5505 lines
160 KiB
C
5505 lines
160 KiB
C
/*-------------------------------------------------------------------------
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*
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* postmaster.c
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* This program acts as a clearing house for requests to the
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* POSTGRES system. Frontend programs connect to the Postmaster,
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* and postmaster forks a new backend process to handle the
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* connection.
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*
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* The postmaster also manages system-wide operations such as
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* startup and shutdown. The postmaster itself doesn't do those
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* operations, mind you --- it just forks off a subprocess to do them
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* at the right times. It also takes care of resetting the system
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* if a backend crashes.
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*
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* The postmaster process creates the shared memory and semaphore
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* pools during startup, but as a rule does not touch them itself.
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* In particular, it is not a member of the PGPROC array of backends
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* and so it cannot participate in lock-manager operations. Keeping
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* the postmaster away from shared memory operations makes it simpler
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* and more reliable. The postmaster is almost always able to recover
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* from crashes of individual backends by resetting shared memory;
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* if it did much with shared memory then it would be prone to crashing
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* along with the backends.
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*
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* When a request message is received, we now fork() immediately.
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* The child process performs authentication of the request, and
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* then becomes a backend if successful. This allows the auth code
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* to be written in a simple single-threaded style (as opposed to the
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* crufty "poor man's multitasking" code that used to be needed).
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* More importantly, it ensures that blockages in non-multithreaded
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* libraries like SSL or PAM cannot cause denial of service to other
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* clients.
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*
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*
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* Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* src/backend/postmaster/postmaster.c
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*
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* NOTES
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*
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* Initialization:
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* The Postmaster sets up shared memory data structures
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* for the backends.
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*
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* Synchronization:
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* The Postmaster shares memory with the backends but should avoid
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* touching shared memory, so as not to become stuck if a crashing
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* backend screws up locks or shared memory. Likewise, the Postmaster
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* should never block on messages from frontend clients.
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*
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* Garbage Collection:
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* The Postmaster cleans up after backends if they have an emergency
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* exit and/or core dump.
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*
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* Error Reporting:
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* Use write_stderr() only for reporting "interactive" errors
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* (essentially, bogus arguments on the command line). Once the
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* postmaster is launched, use ereport().
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include <unistd.h>
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#include <signal.h>
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#include <time.h>
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#include <sys/wait.h>
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#include <ctype.h>
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#include <sys/stat.h>
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#include <sys/socket.h>
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#include <fcntl.h>
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#include <sys/param.h>
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#include <netdb.h>
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#include <limits.h>
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#ifdef USE_BONJOUR
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#include <dns_sd.h>
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#endif
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#ifdef USE_SYSTEMD
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#include <systemd/sd-daemon.h>
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#endif
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#ifdef HAVE_PTHREAD_IS_THREADED_NP
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#include <pthread.h>
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#endif
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#include "access/xlog.h"
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#include "access/xlogrecovery.h"
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#include "common/file_perm.h"
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#include "common/file_utils.h"
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#include "common/ip.h"
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#include "common/pg_prng.h"
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#include "common/string.h"
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#include "lib/ilist.h"
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#include "libpq/libpq.h"
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#include "libpq/pqformat.h"
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#include "libpq/pqsignal.h"
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#include "pg_getopt.h"
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#include "pgstat.h"
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#include "port/pg_bswap.h"
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#include "postmaster/autovacuum.h"
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#include "postmaster/auxprocess.h"
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#include "postmaster/bgworker_internals.h"
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#include "postmaster/pgarch.h"
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#include "postmaster/postmaster.h"
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#include "postmaster/syslogger.h"
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#include "postmaster/walsummarizer.h"
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#include "replication/logicallauncher.h"
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#include "replication/slotsync.h"
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#include "replication/walsender.h"
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#include "storage/fd.h"
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#include "storage/ipc.h"
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#include "storage/pmsignal.h"
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#include "storage/proc.h"
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#include "tcop/tcopprot.h"
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#include "utils/builtins.h"
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#include "utils/datetime.h"
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#include "utils/memutils.h"
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#include "utils/pidfile.h"
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#include "utils/ps_status.h"
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#include "utils/timeout.h"
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#include "utils/timestamp.h"
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#include "utils/varlena.h"
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#ifdef EXEC_BACKEND
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#include "storage/pg_shmem.h"
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#endif
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/*
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* Possible types of a backend. Beyond being the possible bkend_type values in
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* struct bkend, these are OR-able request flag bits for SignalSomeChildren()
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* and CountChildren().
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*/
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#define BACKEND_TYPE_NORMAL 0x0001 /* normal backend */
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#define BACKEND_TYPE_AUTOVAC 0x0002 /* autovacuum worker process */
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#define BACKEND_TYPE_WALSND 0x0004 /* walsender process */
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#define BACKEND_TYPE_BGWORKER 0x0008 /* bgworker process */
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#define BACKEND_TYPE_ALL 0x000F /* OR of all the above */
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/*
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* List of active backends (or child processes anyway; we don't actually
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* know whether a given child has become a backend or is still in the
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* authorization phase). This is used mainly to keep track of how many
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* children we have and send them appropriate signals when necessary.
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*
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* As shown in the above set of backend types, this list includes not only
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* "normal" client sessions, but also autovacuum workers, walsenders, and
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* background workers. (Note that at the time of launch, walsenders are
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* labeled BACKEND_TYPE_NORMAL; we relabel them to BACKEND_TYPE_WALSND
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* upon noticing they've changed their PMChildFlags entry. Hence that check
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* must be done before any operation that needs to distinguish walsenders
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* from normal backends.)
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*
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* Also, "dead_end" children are in it: these are children launched just for
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* the purpose of sending a friendly rejection message to a would-be client.
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* We must track them because they are attached to shared memory, but we know
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* they will never become live backends. dead_end children are not assigned a
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* PMChildSlot. dead_end children have bkend_type NORMAL.
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*
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* "Special" children such as the startup, bgwriter, autovacuum launcher, and
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* slot sync worker tasks are not in this list. They are tracked via StartupPID
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* and other pid_t variables below. (Thus, there can't be more than one of any
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* given "special" child process type. We use BackendList entries for any
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* child process there can be more than one of.)
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*/
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typedef struct bkend
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{
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pid_t pid; /* process id of backend */
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int32 cancel_key; /* cancel key for cancels for this backend */
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int child_slot; /* PMChildSlot for this backend, if any */
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int bkend_type; /* child process flavor, see above */
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bool dead_end; /* is it going to send an error and quit? */
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bool bgworker_notify; /* gets bgworker start/stop notifications */
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dlist_node elem; /* list link in BackendList */
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} Backend;
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static dlist_head BackendList = DLIST_STATIC_INIT(BackendList);
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#ifdef EXEC_BACKEND
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Backend *ShmemBackendArray;
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#endif
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BackgroundWorker *MyBgworkerEntry = NULL;
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/* The socket number we are listening for connections on */
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int PostPortNumber = DEF_PGPORT;
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/* The directory names for Unix socket(s) */
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char *Unix_socket_directories;
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/* The TCP listen address(es) */
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char *ListenAddresses;
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/*
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* SuperuserReservedConnections is the number of backends reserved for
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* superuser use, and ReservedConnections is the number of backends reserved
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* for use by roles with privileges of the pg_use_reserved_connections
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* predefined role. These are taken out of the pool of MaxConnections backend
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* slots, so the number of backend slots available for roles that are neither
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* superuser nor have privileges of pg_use_reserved_connections is
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* (MaxConnections - SuperuserReservedConnections - ReservedConnections).
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*
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* If the number of remaining slots is less than or equal to
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* SuperuserReservedConnections, only superusers can make new connections. If
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* the number of remaining slots is greater than SuperuserReservedConnections
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* but less than or equal to
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* (SuperuserReservedConnections + ReservedConnections), only superusers and
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* roles with privileges of pg_use_reserved_connections can make new
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* connections. Note that pre-existing superuser and
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* pg_use_reserved_connections connections don't count against the limits.
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*/
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int SuperuserReservedConnections;
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int ReservedConnections;
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/* The socket(s) we're listening to. */
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#define MAXLISTEN 64
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static int NumListenSockets = 0;
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static pgsocket *ListenSockets = NULL;
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/* still more option variables */
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bool EnableSSL = false;
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int PreAuthDelay = 0;
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int AuthenticationTimeout = 60;
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bool log_hostname; /* for ps display and logging */
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bool Log_connections = false;
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bool enable_bonjour = false;
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char *bonjour_name;
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bool restart_after_crash = true;
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bool remove_temp_files_after_crash = true;
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bool send_abort_for_crash = false;
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bool send_abort_for_kill = false;
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/* PIDs of special child processes; 0 when not running */
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static pid_t StartupPID = 0,
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BgWriterPID = 0,
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CheckpointerPID = 0,
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WalWriterPID = 0,
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WalReceiverPID = 0,
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WalSummarizerPID = 0,
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AutoVacPID = 0,
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PgArchPID = 0,
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SysLoggerPID = 0,
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SlotSyncWorkerPID = 0;
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/* Startup process's status */
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typedef enum
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{
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STARTUP_NOT_RUNNING,
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STARTUP_RUNNING,
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STARTUP_SIGNALED, /* we sent it a SIGQUIT or SIGKILL */
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STARTUP_CRASHED,
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} StartupStatusEnum;
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static StartupStatusEnum StartupStatus = STARTUP_NOT_RUNNING;
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/* Startup/shutdown state */
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#define NoShutdown 0
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#define SmartShutdown 1
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#define FastShutdown 2
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#define ImmediateShutdown 3
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static int Shutdown = NoShutdown;
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static bool FatalError = false; /* T if recovering from backend crash */
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/*
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* We use a simple state machine to control startup, shutdown, and
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* crash recovery (which is rather like shutdown followed by startup).
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*
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* After doing all the postmaster initialization work, we enter PM_STARTUP
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* state and the startup process is launched. The startup process begins by
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* reading the control file and other preliminary initialization steps.
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* In a normal startup, or after crash recovery, the startup process exits
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* with exit code 0 and we switch to PM_RUN state. However, archive recovery
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* is handled specially since it takes much longer and we would like to support
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* hot standby during archive recovery.
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*
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* When the startup process is ready to start archive recovery, it signals the
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* postmaster, and we switch to PM_RECOVERY state. The background writer and
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* checkpointer are launched, while the startup process continues applying WAL.
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* If Hot Standby is enabled, then, after reaching a consistent point in WAL
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* redo, startup process signals us again, and we switch to PM_HOT_STANDBY
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* state and begin accepting connections to perform read-only queries. When
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* archive recovery is finished, the startup process exits with exit code 0
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* and we switch to PM_RUN state.
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*
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* Normal child backends can only be launched when we are in PM_RUN or
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* PM_HOT_STANDBY state. (connsAllowed can also restrict launching.)
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* In other states we handle connection requests by launching "dead_end"
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* child processes, which will simply send the client an error message and
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* quit. (We track these in the BackendList so that we can know when they
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* are all gone; this is important because they're still connected to shared
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* memory, and would interfere with an attempt to destroy the shmem segment,
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* possibly leading to SHMALL failure when we try to make a new one.)
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* In PM_WAIT_DEAD_END state we are waiting for all the dead_end children
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* to drain out of the system, and therefore stop accepting connection
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* requests at all until the last existing child has quit (which hopefully
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* will not be very long).
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*
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* Notice that this state variable does not distinguish *why* we entered
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* states later than PM_RUN --- Shutdown and FatalError must be consulted
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* to find that out. FatalError is never true in PM_RECOVERY, PM_HOT_STANDBY,
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* or PM_RUN states, nor in PM_SHUTDOWN states (because we don't enter those
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* states when trying to recover from a crash). It can be true in PM_STARTUP
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* state, because we don't clear it until we've successfully started WAL redo.
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*/
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typedef enum
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{
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PM_INIT, /* postmaster starting */
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PM_STARTUP, /* waiting for startup subprocess */
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PM_RECOVERY, /* in archive recovery mode */
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PM_HOT_STANDBY, /* in hot standby mode */
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PM_RUN, /* normal "database is alive" state */
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PM_STOP_BACKENDS, /* need to stop remaining backends */
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PM_WAIT_BACKENDS, /* waiting for live backends to exit */
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PM_SHUTDOWN, /* waiting for checkpointer to do shutdown
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* ckpt */
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PM_SHUTDOWN_2, /* waiting for archiver and walsenders to
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* finish */
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PM_WAIT_DEAD_END, /* waiting for dead_end children to exit */
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PM_NO_CHILDREN, /* all important children have exited */
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} PMState;
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static PMState pmState = PM_INIT;
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/*
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* While performing a "smart shutdown", we restrict new connections but stay
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* in PM_RUN or PM_HOT_STANDBY state until all the client backends are gone.
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* connsAllowed is a sub-state indicator showing the active restriction.
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* It is of no interest unless pmState is PM_RUN or PM_HOT_STANDBY.
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*/
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static bool connsAllowed = true;
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/* Start time of SIGKILL timeout during immediate shutdown or child crash */
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/* Zero means timeout is not running */
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static time_t AbortStartTime = 0;
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/* Length of said timeout */
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#define SIGKILL_CHILDREN_AFTER_SECS 5
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static bool ReachedNormalRunning = false; /* T if we've reached PM_RUN */
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bool ClientAuthInProgress = false; /* T during new-client
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* authentication */
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bool redirection_done = false; /* stderr redirected for syslogger? */
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/* received START_AUTOVAC_LAUNCHER signal */
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static bool start_autovac_launcher = false;
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/* the launcher needs to be signaled to communicate some condition */
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static bool avlauncher_needs_signal = false;
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/* received START_WALRECEIVER signal */
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static bool WalReceiverRequested = false;
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/* set when there's a worker that needs to be started up */
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static bool StartWorkerNeeded = true;
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static bool HaveCrashedWorker = false;
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/* set when signals arrive */
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static volatile sig_atomic_t pending_pm_pmsignal;
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static volatile sig_atomic_t pending_pm_child_exit;
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static volatile sig_atomic_t pending_pm_reload_request;
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static volatile sig_atomic_t pending_pm_shutdown_request;
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static volatile sig_atomic_t pending_pm_fast_shutdown_request;
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static volatile sig_atomic_t pending_pm_immediate_shutdown_request;
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/* event multiplexing object */
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static WaitEventSet *pm_wait_set;
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#ifdef USE_SSL
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/* Set when and if SSL has been initialized properly */
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static bool LoadedSSL = false;
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#endif
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#ifdef USE_BONJOUR
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static DNSServiceRef bonjour_sdref = NULL;
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#endif
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/*
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* postmaster.c - function prototypes
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*/
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static void CloseServerPorts(int status, Datum arg);
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static void unlink_external_pid_file(int status, Datum arg);
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static void getInstallationPaths(const char *argv0);
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static void checkControlFile(void);
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static void handle_pm_pmsignal_signal(SIGNAL_ARGS);
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static void handle_pm_child_exit_signal(SIGNAL_ARGS);
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static void handle_pm_reload_request_signal(SIGNAL_ARGS);
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static void handle_pm_shutdown_request_signal(SIGNAL_ARGS);
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static void process_pm_pmsignal(void);
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static void process_pm_child_exit(void);
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static void process_pm_reload_request(void);
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static void process_pm_shutdown_request(void);
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static void process_startup_packet_die(SIGNAL_ARGS);
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static void dummy_handler(SIGNAL_ARGS);
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static void StartupPacketTimeoutHandler(void);
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static void CleanupBackend(int pid, int exitstatus);
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static bool CleanupBackgroundWorker(int pid, int exitstatus);
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static void HandleChildCrash(int pid, int exitstatus, const char *procname);
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static void LogChildExit(int lev, const char *procname,
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int pid, int exitstatus);
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static void PostmasterStateMachine(void);
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/* Return value of canAcceptConnections() */
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typedef enum CAC_state
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{
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CAC_OK,
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CAC_STARTUP,
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CAC_SHUTDOWN,
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CAC_RECOVERY,
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CAC_NOTCONSISTENT,
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CAC_TOOMANY,
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} CAC_state;
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static void BackendInitialize(ClientSocket *client_sock, CAC_state cac);
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static void ExitPostmaster(int status) pg_attribute_noreturn();
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static int ServerLoop(void);
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static int BackendStartup(ClientSocket *client_sock);
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static int ProcessStartupPacket(Port *port, bool ssl_done, bool gss_done);
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static void SendNegotiateProtocolVersion(List *unrecognized_protocol_options);
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static void processCancelRequest(Port *port, void *pkt);
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static void report_fork_failure_to_client(ClientSocket *client_sock, int errnum);
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static CAC_state canAcceptConnections(int backend_type);
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static bool RandomCancelKey(int32 *cancel_key);
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static void signal_child(pid_t pid, int signal);
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static void sigquit_child(pid_t pid);
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static bool SignalSomeChildren(int signal, int target);
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static void TerminateChildren(int signal);
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#define SignalChildren(sig) SignalSomeChildren(sig, BACKEND_TYPE_ALL)
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static int CountChildren(int target);
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static bool assign_backendlist_entry(RegisteredBgWorker *rw);
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static void maybe_start_bgworkers(void);
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static bool CreateOptsFile(int argc, char *argv[], char *fullprogname);
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static pid_t StartChildProcess(BackendType type);
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static void StartAutovacuumWorker(void);
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static void MaybeStartWalReceiver(void);
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static void MaybeStartWalSummarizer(void);
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static void InitPostmasterDeathWatchHandle(void);
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static void MaybeStartSlotSyncWorker(void);
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/*
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* Archiver is allowed to start up at the current postmaster state?
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*
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* If WAL archiving is enabled always, we are allowed to start archiver
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* even during recovery.
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*/
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#define PgArchStartupAllowed() \
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(((XLogArchivingActive() && pmState == PM_RUN) || \
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(XLogArchivingAlways() && \
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(pmState == PM_RECOVERY || pmState == PM_HOT_STANDBY))) && \
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PgArchCanRestart())
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#ifdef EXEC_BACKEND
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#ifdef WIN32
|
|
#define WNOHANG 0 /* ignored, so any integer value will do */
|
|
|
|
static pid_t waitpid(pid_t pid, int *exitstatus, int options);
|
|
static void WINAPI pgwin32_deadchild_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired);
|
|
|
|
static HANDLE win32ChildQueue;
|
|
|
|
typedef struct
|
|
{
|
|
HANDLE waitHandle;
|
|
HANDLE procHandle;
|
|
DWORD procId;
|
|
} win32_deadchild_waitinfo;
|
|
#endif /* WIN32 */
|
|
|
|
static void ShmemBackendArrayAdd(Backend *bn);
|
|
static void ShmemBackendArrayRemove(Backend *bn);
|
|
#endif /* EXEC_BACKEND */
|
|
|
|
/* Macros to check exit status of a child process */
|
|
#define EXIT_STATUS_0(st) ((st) == 0)
|
|
#define EXIT_STATUS_1(st) (WIFEXITED(st) && WEXITSTATUS(st) == 1)
|
|
#define EXIT_STATUS_3(st) (WIFEXITED(st) && WEXITSTATUS(st) == 3)
|
|
|
|
#ifndef WIN32
|
|
/*
|
|
* File descriptors for pipe used to monitor if postmaster is alive.
|
|
* First is POSTMASTER_FD_WATCH, second is POSTMASTER_FD_OWN.
|
|
*/
|
|
int postmaster_alive_fds[2] = {-1, -1};
|
|
#else
|
|
/* Process handle of postmaster used for the same purpose on Windows */
|
|
HANDLE PostmasterHandle;
|
|
#endif
|
|
|
|
/*
|
|
* Postmaster main entry point
|
|
*/
|
|
void
|
|
PostmasterMain(int argc, char *argv[])
|
|
{
|
|
int opt;
|
|
int status;
|
|
char *userDoption = NULL;
|
|
bool listen_addr_saved = false;
|
|
char *output_config_variable = NULL;
|
|
|
|
InitProcessGlobals();
|
|
|
|
PostmasterPid = MyProcPid;
|
|
|
|
IsPostmasterEnvironment = true;
|
|
|
|
/*
|
|
* Start our win32 signal implementation
|
|
*/
|
|
#ifdef WIN32
|
|
pgwin32_signal_initialize();
|
|
#endif
|
|
|
|
/*
|
|
* We should not be creating any files or directories before we check the
|
|
* data directory (see checkDataDir()), but just in case set the umask to
|
|
* the most restrictive (owner-only) permissions.
|
|
*
|
|
* checkDataDir() will reset the umask based on the data directory
|
|
* permissions.
|
|
*/
|
|
umask(PG_MODE_MASK_OWNER);
|
|
|
|
/*
|
|
* By default, palloc() requests in the postmaster will be allocated in
|
|
* the PostmasterContext, which is space that can be recycled by backends.
|
|
* Allocated data that needs to be available to backends should be
|
|
* allocated in TopMemoryContext.
|
|
*/
|
|
PostmasterContext = AllocSetContextCreate(TopMemoryContext,
|
|
"Postmaster",
|
|
ALLOCSET_DEFAULT_SIZES);
|
|
MemoryContextSwitchTo(PostmasterContext);
|
|
|
|
/* Initialize paths to installation files */
|
|
getInstallationPaths(argv[0]);
|
|
|
|
/*
|
|
* Set up signal handlers for the postmaster process.
|
|
*
|
|
* CAUTION: when changing this list, check for side-effects on the signal
|
|
* handling setup of child processes. See tcop/postgres.c,
|
|
* bootstrap/bootstrap.c, postmaster/bgwriter.c, postmaster/walwriter.c,
|
|
* postmaster/autovacuum.c, postmaster/pgarch.c, postmaster/syslogger.c,
|
|
* postmaster/bgworker.c and postmaster/checkpointer.c.
|
|
*/
|
|
pqinitmask();
|
|
sigprocmask(SIG_SETMASK, &BlockSig, NULL);
|
|
|
|
pqsignal(SIGHUP, handle_pm_reload_request_signal);
|
|
pqsignal(SIGINT, handle_pm_shutdown_request_signal);
|
|
pqsignal(SIGQUIT, handle_pm_shutdown_request_signal);
|
|
pqsignal(SIGTERM, handle_pm_shutdown_request_signal);
|
|
pqsignal(SIGALRM, SIG_IGN); /* ignored */
|
|
pqsignal(SIGPIPE, SIG_IGN); /* ignored */
|
|
pqsignal(SIGUSR1, handle_pm_pmsignal_signal);
|
|
pqsignal(SIGUSR2, dummy_handler); /* unused, reserve for children */
|
|
pqsignal(SIGCHLD, handle_pm_child_exit_signal);
|
|
|
|
/* This may configure SIGURG, depending on platform. */
|
|
InitializeLatchSupport();
|
|
InitProcessLocalLatch();
|
|
|
|
/*
|
|
* No other place in Postgres should touch SIGTTIN/SIGTTOU handling. We
|
|
* ignore those signals in a postmaster environment, so that there is no
|
|
* risk of a child process freezing up due to writing to stderr. But for
|
|
* a standalone backend, their default handling is reasonable. Hence, all
|
|
* child processes should just allow the inherited settings to stand.
|
|
*/
|
|
#ifdef SIGTTIN
|
|
pqsignal(SIGTTIN, SIG_IGN); /* ignored */
|
|
#endif
|
|
#ifdef SIGTTOU
|
|
pqsignal(SIGTTOU, SIG_IGN); /* ignored */
|
|
#endif
|
|
|
|
/* ignore SIGXFSZ, so that ulimit violations work like disk full */
|
|
#ifdef SIGXFSZ
|
|
pqsignal(SIGXFSZ, SIG_IGN); /* ignored */
|
|
#endif
|
|
|
|
/* Begin accepting signals. */
|
|
sigprocmask(SIG_SETMASK, &UnBlockSig, NULL);
|
|
|
|
/*
|
|
* Options setup
|
|
*/
|
|
InitializeGUCOptions();
|
|
|
|
opterr = 1;
|
|
|
|
/*
|
|
* Parse command-line options. CAUTION: keep this in sync with
|
|
* tcop/postgres.c (the option sets should not conflict) and with the
|
|
* common help() function in main/main.c.
|
|
*/
|
|
while ((opt = getopt(argc, argv, "B:bC:c:D:d:EeFf:h:ijk:lN:OPp:r:S:sTt:W:-:")) != -1)
|
|
{
|
|
switch (opt)
|
|
{
|
|
case 'B':
|
|
SetConfigOption("shared_buffers", optarg, PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 'b':
|
|
/* Undocumented flag used for binary upgrades */
|
|
IsBinaryUpgrade = true;
|
|
break;
|
|
|
|
case 'C':
|
|
output_config_variable = strdup(optarg);
|
|
break;
|
|
|
|
case 'c':
|
|
case '-':
|
|
{
|
|
char *name,
|
|
*value;
|
|
|
|
ParseLongOption(optarg, &name, &value);
|
|
if (!value)
|
|
{
|
|
if (opt == '-')
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_SYNTAX_ERROR),
|
|
errmsg("--%s requires a value",
|
|
optarg)));
|
|
else
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_SYNTAX_ERROR),
|
|
errmsg("-c %s requires a value",
|
|
optarg)));
|
|
}
|
|
|
|
SetConfigOption(name, value, PGC_POSTMASTER, PGC_S_ARGV);
|
|
pfree(name);
|
|
pfree(value);
|
|
break;
|
|
}
|
|
|
|
case 'D':
|
|
userDoption = strdup(optarg);
|
|
break;
|
|
|
|
case 'd':
|
|
set_debug_options(atoi(optarg), PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 'E':
|
|
SetConfigOption("log_statement", "all", PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 'e':
|
|
SetConfigOption("datestyle", "euro", PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 'F':
|
|
SetConfigOption("fsync", "false", PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 'f':
|
|
if (!set_plan_disabling_options(optarg, PGC_POSTMASTER, PGC_S_ARGV))
|
|
{
|
|
write_stderr("%s: invalid argument for option -f: \"%s\"\n",
|
|
progname, optarg);
|
|
ExitPostmaster(1);
|
|
}
|
|
break;
|
|
|
|
case 'h':
|
|
SetConfigOption("listen_addresses", optarg, PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 'i':
|
|
SetConfigOption("listen_addresses", "*", PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 'j':
|
|
/* only used by interactive backend */
|
|
break;
|
|
|
|
case 'k':
|
|
SetConfigOption("unix_socket_directories", optarg, PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 'l':
|
|
SetConfigOption("ssl", "true", PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 'N':
|
|
SetConfigOption("max_connections", optarg, PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 'O':
|
|
SetConfigOption("allow_system_table_mods", "true", PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 'P':
|
|
SetConfigOption("ignore_system_indexes", "true", PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 'p':
|
|
SetConfigOption("port", optarg, PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 'r':
|
|
/* only used by single-user backend */
|
|
break;
|
|
|
|
case 'S':
|
|
SetConfigOption("work_mem", optarg, PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 's':
|
|
SetConfigOption("log_statement_stats", "true", PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 'T':
|
|
|
|
/*
|
|
* This option used to be defined as sending SIGSTOP after a
|
|
* backend crash, but sending SIGABRT seems more useful.
|
|
*/
|
|
SetConfigOption("send_abort_for_crash", "true", PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
case 't':
|
|
{
|
|
const char *tmp = get_stats_option_name(optarg);
|
|
|
|
if (tmp)
|
|
{
|
|
SetConfigOption(tmp, "true", PGC_POSTMASTER, PGC_S_ARGV);
|
|
}
|
|
else
|
|
{
|
|
write_stderr("%s: invalid argument for option -t: \"%s\"\n",
|
|
progname, optarg);
|
|
ExitPostmaster(1);
|
|
}
|
|
break;
|
|
}
|
|
|
|
case 'W':
|
|
SetConfigOption("post_auth_delay", optarg, PGC_POSTMASTER, PGC_S_ARGV);
|
|
break;
|
|
|
|
default:
|
|
write_stderr("Try \"%s --help\" for more information.\n",
|
|
progname);
|
|
ExitPostmaster(1);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Postmaster accepts no non-option switch arguments.
|
|
*/
|
|
if (optind < argc)
|
|
{
|
|
write_stderr("%s: invalid argument: \"%s\"\n",
|
|
progname, argv[optind]);
|
|
write_stderr("Try \"%s --help\" for more information.\n",
|
|
progname);
|
|
ExitPostmaster(1);
|
|
}
|
|
|
|
/*
|
|
* Locate the proper configuration files and data directory, and read
|
|
* postgresql.conf for the first time.
|
|
*/
|
|
if (!SelectConfigFiles(userDoption, progname))
|
|
ExitPostmaster(2);
|
|
|
|
if (output_config_variable != NULL)
|
|
{
|
|
/*
|
|
* If this is a runtime-computed GUC, it hasn't yet been initialized,
|
|
* and the present value is not useful. However, this is a convenient
|
|
* place to print the value for most GUCs because it is safe to run
|
|
* postmaster startup to this point even if the server is already
|
|
* running. For the handful of runtime-computed GUCs that we cannot
|
|
* provide meaningful values for yet, we wait until later in
|
|
* postmaster startup to print the value. We won't be able to use -C
|
|
* on running servers for those GUCs, but using this option now would
|
|
* lead to incorrect results for them.
|
|
*/
|
|
int flags = GetConfigOptionFlags(output_config_variable, true);
|
|
|
|
if ((flags & GUC_RUNTIME_COMPUTED) == 0)
|
|
{
|
|
/*
|
|
* "-C guc" was specified, so print GUC's value and exit. No
|
|
* extra permission check is needed because the user is reading
|
|
* inside the data dir.
|
|
*/
|
|
const char *config_val = GetConfigOption(output_config_variable,
|
|
false, false);
|
|
|
|
puts(config_val ? config_val : "");
|
|
ExitPostmaster(0);
|
|
}
|
|
|
|
/*
|
|
* A runtime-computed GUC will be printed later on. As we initialize
|
|
* a server startup sequence, silence any log messages that may show
|
|
* up in the output generated. FATAL and more severe messages are
|
|
* useful to show, even if one would only expect at least PANIC. LOG
|
|
* entries are hidden.
|
|
*/
|
|
SetConfigOption("log_min_messages", "FATAL", PGC_SUSET,
|
|
PGC_S_OVERRIDE);
|
|
}
|
|
|
|
/* Verify that DataDir looks reasonable */
|
|
checkDataDir();
|
|
|
|
/* Check that pg_control exists */
|
|
checkControlFile();
|
|
|
|
/* And switch working directory into it */
|
|
ChangeToDataDir();
|
|
|
|
/*
|
|
* Check for invalid combinations of GUC settings.
|
|
*/
|
|
if (SuperuserReservedConnections + ReservedConnections >= MaxConnections)
|
|
{
|
|
write_stderr("%s: superuser_reserved_connections (%d) plus reserved_connections (%d) must be less than max_connections (%d)\n",
|
|
progname,
|
|
SuperuserReservedConnections, ReservedConnections,
|
|
MaxConnections);
|
|
ExitPostmaster(1);
|
|
}
|
|
if (XLogArchiveMode > ARCHIVE_MODE_OFF && wal_level == WAL_LEVEL_MINIMAL)
|
|
ereport(ERROR,
|
|
(errmsg("WAL archival cannot be enabled when wal_level is \"minimal\"")));
|
|
if (max_wal_senders > 0 && wal_level == WAL_LEVEL_MINIMAL)
|
|
ereport(ERROR,
|
|
(errmsg("WAL streaming (max_wal_senders > 0) requires wal_level \"replica\" or \"logical\"")));
|
|
if (summarize_wal && wal_level == WAL_LEVEL_MINIMAL)
|
|
ereport(ERROR,
|
|
(errmsg("WAL cannot be summarized when wal_level is \"minimal\"")));
|
|
|
|
/*
|
|
* Other one-time internal sanity checks can go here, if they are fast.
|
|
* (Put any slow processing further down, after postmaster.pid creation.)
|
|
*/
|
|
if (!CheckDateTokenTables())
|
|
{
|
|
write_stderr("%s: invalid datetoken tables, please fix\n", progname);
|
|
ExitPostmaster(1);
|
|
}
|
|
|
|
/*
|
|
* Now that we are done processing the postmaster arguments, reset
|
|
* getopt(3) library so that it will work correctly in subprocesses.
|
|
*/
|
|
optind = 1;
|
|
#ifdef HAVE_INT_OPTRESET
|
|
optreset = 1; /* some systems need this too */
|
|
#endif
|
|
|
|
/* For debugging: display postmaster environment */
|
|
{
|
|
extern char **environ;
|
|
char **p;
|
|
|
|
ereport(DEBUG3,
|
|
(errmsg_internal("%s: PostmasterMain: initial environment dump:",
|
|
progname)));
|
|
ereport(DEBUG3,
|
|
(errmsg_internal("-----------------------------------------")));
|
|
for (p = environ; *p; ++p)
|
|
ereport(DEBUG3,
|
|
(errmsg_internal("\t%s", *p)));
|
|
ereport(DEBUG3,
|
|
(errmsg_internal("-----------------------------------------")));
|
|
}
|
|
|
|
/*
|
|
* Create lockfile for data directory.
|
|
*
|
|
* We want to do this before we try to grab the input sockets, because the
|
|
* data directory interlock is more reliable than the socket-file
|
|
* interlock (thanks to whoever decided to put socket files in /tmp :-().
|
|
* For the same reason, it's best to grab the TCP socket(s) before the
|
|
* Unix socket(s).
|
|
*
|
|
* Also note that this internally sets up the on_proc_exit function that
|
|
* is responsible for removing both data directory and socket lockfiles;
|
|
* so it must happen before opening sockets so that at exit, the socket
|
|
* lockfiles go away after CloseServerPorts runs.
|
|
*/
|
|
CreateDataDirLockFile(true);
|
|
|
|
/*
|
|
* Read the control file (for error checking and config info).
|
|
*
|
|
* Since we verify the control file's CRC, this has a useful side effect
|
|
* on machines where we need a run-time test for CRC support instructions.
|
|
* The postmaster will do the test once at startup, and then its child
|
|
* processes will inherit the correct function pointer and not need to
|
|
* repeat the test.
|
|
*/
|
|
LocalProcessControlFile(false);
|
|
|
|
/*
|
|
* Register the apply launcher. It's probably a good idea to call this
|
|
* before any modules had a chance to take the background worker slots.
|
|
*/
|
|
ApplyLauncherRegister();
|
|
|
|
/*
|
|
* process any libraries that should be preloaded at postmaster start
|
|
*/
|
|
process_shared_preload_libraries();
|
|
|
|
/*
|
|
* Initialize SSL library, if specified.
|
|
*/
|
|
#ifdef USE_SSL
|
|
if (EnableSSL)
|
|
{
|
|
(void) secure_initialize(true);
|
|
LoadedSSL = true;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Now that loadable modules have had their chance to alter any GUCs,
|
|
* calculate MaxBackends.
|
|
*/
|
|
InitializeMaxBackends();
|
|
|
|
/*
|
|
* Give preloaded libraries a chance to request additional shared memory.
|
|
*/
|
|
process_shmem_requests();
|
|
|
|
/*
|
|
* Now that loadable modules have had their chance to request additional
|
|
* shared memory, determine the value of any runtime-computed GUCs that
|
|
* depend on the amount of shared memory required.
|
|
*/
|
|
InitializeShmemGUCs();
|
|
|
|
/*
|
|
* Now that modules have been loaded, we can process any custom resource
|
|
* managers specified in the wal_consistency_checking GUC.
|
|
*/
|
|
InitializeWalConsistencyChecking();
|
|
|
|
/*
|
|
* If -C was specified with a runtime-computed GUC, we held off printing
|
|
* the value earlier, as the GUC was not yet initialized. We handle -C
|
|
* for most GUCs before we lock the data directory so that the option may
|
|
* be used on a running server. However, a handful of GUCs are runtime-
|
|
* computed and do not have meaningful values until after locking the data
|
|
* directory, and we cannot safely calculate their values earlier on a
|
|
* running server. At this point, such GUCs should be properly
|
|
* initialized, and we haven't yet set up shared memory, so this is a good
|
|
* time to handle the -C option for these special GUCs.
|
|
*/
|
|
if (output_config_variable != NULL)
|
|
{
|
|
const char *config_val = GetConfigOption(output_config_variable,
|
|
false, false);
|
|
|
|
puts(config_val ? config_val : "");
|
|
ExitPostmaster(0);
|
|
}
|
|
|
|
/*
|
|
* Set up shared memory and semaphores.
|
|
*
|
|
* Note: if using SysV shmem and/or semas, each postmaster startup will
|
|
* normally choose the same IPC keys. This helps ensure that we will
|
|
* clean up dead IPC objects if the postmaster crashes and is restarted.
|
|
*/
|
|
CreateSharedMemoryAndSemaphores();
|
|
|
|
/*
|
|
* Estimate number of openable files. This must happen after setting up
|
|
* semaphores, because on some platforms semaphores count as open files.
|
|
*/
|
|
set_max_safe_fds();
|
|
|
|
/*
|
|
* Set reference point for stack-depth checking.
|
|
*/
|
|
(void) set_stack_base();
|
|
|
|
/*
|
|
* Initialize pipe (or process handle on Windows) that allows children to
|
|
* wake up from sleep on postmaster death.
|
|
*/
|
|
InitPostmasterDeathWatchHandle();
|
|
|
|
#ifdef WIN32
|
|
|
|
/*
|
|
* Initialize I/O completion port used to deliver list of dead children.
|
|
*/
|
|
win32ChildQueue = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 1);
|
|
if (win32ChildQueue == NULL)
|
|
ereport(FATAL,
|
|
(errmsg("could not create I/O completion port for child queue")));
|
|
#endif
|
|
|
|
#ifdef EXEC_BACKEND
|
|
/* Write out nondefault GUC settings for child processes to use */
|
|
write_nondefault_variables(PGC_POSTMASTER);
|
|
|
|
/*
|
|
* Clean out the temp directory used to transmit parameters to child
|
|
* processes (see internal_forkexec). We must do this before launching
|
|
* any child processes, else we have a race condition: we could remove a
|
|
* parameter file before the child can read it. It should be safe to do
|
|
* so now, because we verified earlier that there are no conflicting
|
|
* Postgres processes in this data directory.
|
|
*/
|
|
RemovePgTempFilesInDir(PG_TEMP_FILES_DIR, true, false);
|
|
#endif
|
|
|
|
/*
|
|
* Forcibly remove the files signaling a standby promotion request.
|
|
* Otherwise, the existence of those files triggers a promotion too early,
|
|
* whether a user wants that or not.
|
|
*
|
|
* This removal of files is usually unnecessary because they can exist
|
|
* only during a few moments during a standby promotion. However there is
|
|
* a race condition: if pg_ctl promote is executed and creates the files
|
|
* during a promotion, the files can stay around even after the server is
|
|
* brought up to be the primary. Then, if a new standby starts by using
|
|
* the backup taken from the new primary, the files can exist at server
|
|
* startup and must be removed in order to avoid an unexpected promotion.
|
|
*
|
|
* Note that promotion signal files need to be removed before the startup
|
|
* process is invoked. Because, after that, they can be used by
|
|
* postmaster's SIGUSR1 signal handler.
|
|
*/
|
|
RemovePromoteSignalFiles();
|
|
|
|
/* Do the same for logrotate signal file */
|
|
RemoveLogrotateSignalFiles();
|
|
|
|
/* Remove any outdated file holding the current log filenames. */
|
|
if (unlink(LOG_METAINFO_DATAFILE) < 0 && errno != ENOENT)
|
|
ereport(LOG,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not remove file \"%s\": %m",
|
|
LOG_METAINFO_DATAFILE)));
|
|
|
|
/*
|
|
* If enabled, start up syslogger collection subprocess
|
|
*/
|
|
SysLoggerPID = SysLogger_Start();
|
|
|
|
/*
|
|
* Reset whereToSendOutput from DestDebug (its starting state) to
|
|
* DestNone. This stops ereport from sending log messages to stderr unless
|
|
* Log_destination permits. We don't do this until the postmaster is
|
|
* fully launched, since startup failures may as well be reported to
|
|
* stderr.
|
|
*
|
|
* If we are in fact disabling logging to stderr, first emit a log message
|
|
* saying so, to provide a breadcrumb trail for users who may not remember
|
|
* that their logging is configured to go somewhere else.
|
|
*/
|
|
if (!(Log_destination & LOG_DESTINATION_STDERR))
|
|
ereport(LOG,
|
|
(errmsg("ending log output to stderr"),
|
|
errhint("Future log output will go to log destination \"%s\".",
|
|
Log_destination_string)));
|
|
|
|
whereToSendOutput = DestNone;
|
|
|
|
/*
|
|
* Report server startup in log. While we could emit this much earlier,
|
|
* it seems best to do so after starting the log collector, if we intend
|
|
* to use one.
|
|
*/
|
|
ereport(LOG,
|
|
(errmsg("starting %s", PG_VERSION_STR)));
|
|
|
|
/*
|
|
* Establish input sockets.
|
|
*
|
|
* First set up an on_proc_exit function that's charged with closing the
|
|
* sockets again at postmaster shutdown.
|
|
*/
|
|
ListenSockets = palloc(MAXLISTEN * sizeof(pgsocket));
|
|
on_proc_exit(CloseServerPorts, 0);
|
|
|
|
if (ListenAddresses)
|
|
{
|
|
char *rawstring;
|
|
List *elemlist;
|
|
ListCell *l;
|
|
int success = 0;
|
|
|
|
/* Need a modifiable copy of ListenAddresses */
|
|
rawstring = pstrdup(ListenAddresses);
|
|
|
|
/* Parse string into list of hostnames */
|
|
if (!SplitGUCList(rawstring, ',', &elemlist))
|
|
{
|
|
/* syntax error in list */
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
|
|
errmsg("invalid list syntax in parameter \"%s\"",
|
|
"listen_addresses")));
|
|
}
|
|
|
|
foreach(l, elemlist)
|
|
{
|
|
char *curhost = (char *) lfirst(l);
|
|
|
|
if (strcmp(curhost, "*") == 0)
|
|
status = ListenServerPort(AF_UNSPEC, NULL,
|
|
(unsigned short) PostPortNumber,
|
|
NULL,
|
|
ListenSockets,
|
|
&NumListenSockets,
|
|
MAXLISTEN);
|
|
else
|
|
status = ListenServerPort(AF_UNSPEC, curhost,
|
|
(unsigned short) PostPortNumber,
|
|
NULL,
|
|
ListenSockets,
|
|
&NumListenSockets,
|
|
MAXLISTEN);
|
|
|
|
if (status == STATUS_OK)
|
|
{
|
|
success++;
|
|
/* record the first successful host addr in lockfile */
|
|
if (!listen_addr_saved)
|
|
{
|
|
AddToDataDirLockFile(LOCK_FILE_LINE_LISTEN_ADDR, curhost);
|
|
listen_addr_saved = true;
|
|
}
|
|
}
|
|
else
|
|
ereport(WARNING,
|
|
(errmsg("could not create listen socket for \"%s\"",
|
|
curhost)));
|
|
}
|
|
|
|
if (!success && elemlist != NIL)
|
|
ereport(FATAL,
|
|
(errmsg("could not create any TCP/IP sockets")));
|
|
|
|
list_free(elemlist);
|
|
pfree(rawstring);
|
|
}
|
|
|
|
#ifdef USE_BONJOUR
|
|
/* Register for Bonjour only if we opened TCP socket(s) */
|
|
if (enable_bonjour && NumListenSockets > 0)
|
|
{
|
|
DNSServiceErrorType err;
|
|
|
|
/*
|
|
* We pass 0 for interface_index, which will result in registering on
|
|
* all "applicable" interfaces. It's not entirely clear from the
|
|
* DNS-SD docs whether this would be appropriate if we have bound to
|
|
* just a subset of the available network interfaces.
|
|
*/
|
|
err = DNSServiceRegister(&bonjour_sdref,
|
|
0,
|
|
0,
|
|
bonjour_name,
|
|
"_postgresql._tcp.",
|
|
NULL,
|
|
NULL,
|
|
pg_hton16(PostPortNumber),
|
|
0,
|
|
NULL,
|
|
NULL,
|
|
NULL);
|
|
if (err != kDNSServiceErr_NoError)
|
|
ereport(LOG,
|
|
(errmsg("DNSServiceRegister() failed: error code %ld",
|
|
(long) err)));
|
|
|
|
/*
|
|
* We don't bother to read the mDNS daemon's reply, and we expect that
|
|
* it will automatically terminate our registration when the socket is
|
|
* closed at postmaster termination. So there's nothing more to be
|
|
* done here. However, the bonjour_sdref is kept around so that
|
|
* forked children can close their copies of the socket.
|
|
*/
|
|
}
|
|
#endif
|
|
|
|
if (Unix_socket_directories)
|
|
{
|
|
char *rawstring;
|
|
List *elemlist;
|
|
ListCell *l;
|
|
int success = 0;
|
|
|
|
/* Need a modifiable copy of Unix_socket_directories */
|
|
rawstring = pstrdup(Unix_socket_directories);
|
|
|
|
/* Parse string into list of directories */
|
|
if (!SplitDirectoriesString(rawstring, ',', &elemlist))
|
|
{
|
|
/* syntax error in list */
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
|
|
errmsg("invalid list syntax in parameter \"%s\"",
|
|
"unix_socket_directories")));
|
|
}
|
|
|
|
foreach(l, elemlist)
|
|
{
|
|
char *socketdir = (char *) lfirst(l);
|
|
|
|
status = ListenServerPort(AF_UNIX, NULL,
|
|
(unsigned short) PostPortNumber,
|
|
socketdir,
|
|
ListenSockets,
|
|
&NumListenSockets,
|
|
MAXLISTEN);
|
|
|
|
if (status == STATUS_OK)
|
|
{
|
|
success++;
|
|
/* record the first successful Unix socket in lockfile */
|
|
if (success == 1)
|
|
AddToDataDirLockFile(LOCK_FILE_LINE_SOCKET_DIR, socketdir);
|
|
}
|
|
else
|
|
ereport(WARNING,
|
|
(errmsg("could not create Unix-domain socket in directory \"%s\"",
|
|
socketdir)));
|
|
}
|
|
|
|
if (!success && elemlist != NIL)
|
|
ereport(FATAL,
|
|
(errmsg("could not create any Unix-domain sockets")));
|
|
|
|
list_free_deep(elemlist);
|
|
pfree(rawstring);
|
|
}
|
|
|
|
/*
|
|
* check that we have some socket to listen on
|
|
*/
|
|
if (NumListenSockets == 0)
|
|
ereport(FATAL,
|
|
(errmsg("no socket created for listening")));
|
|
|
|
/*
|
|
* If no valid TCP ports, write an empty line for listen address,
|
|
* indicating the Unix socket must be used. Note that this line is not
|
|
* added to the lock file until there is a socket backing it.
|
|
*/
|
|
if (!listen_addr_saved)
|
|
AddToDataDirLockFile(LOCK_FILE_LINE_LISTEN_ADDR, "");
|
|
|
|
/*
|
|
* Record postmaster options. We delay this till now to avoid recording
|
|
* bogus options (eg, unusable port number).
|
|
*/
|
|
if (!CreateOptsFile(argc, argv, my_exec_path))
|
|
ExitPostmaster(1);
|
|
|
|
/*
|
|
* Write the external PID file if requested
|
|
*/
|
|
if (external_pid_file)
|
|
{
|
|
FILE *fpidfile = fopen(external_pid_file, "w");
|
|
|
|
if (fpidfile)
|
|
{
|
|
fprintf(fpidfile, "%d\n", MyProcPid);
|
|
fclose(fpidfile);
|
|
|
|
/* Make PID file world readable */
|
|
if (chmod(external_pid_file, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH) != 0)
|
|
write_stderr("%s: could not change permissions of external PID file \"%s\": %m\n",
|
|
progname, external_pid_file);
|
|
}
|
|
else
|
|
write_stderr("%s: could not write external PID file \"%s\": %m\n",
|
|
progname, external_pid_file);
|
|
|
|
on_proc_exit(unlink_external_pid_file, 0);
|
|
}
|
|
|
|
/*
|
|
* Remove old temporary files. At this point there can be no other
|
|
* Postgres processes running in this directory, so this should be safe.
|
|
*/
|
|
RemovePgTempFiles();
|
|
|
|
/*
|
|
* Initialize the autovacuum subsystem (again, no process start yet)
|
|
*/
|
|
autovac_init();
|
|
|
|
/*
|
|
* Load configuration files for client authentication.
|
|
*/
|
|
if (!load_hba())
|
|
{
|
|
/*
|
|
* It makes no sense to continue if we fail to load the HBA file,
|
|
* since there is no way to connect to the database in this case.
|
|
*/
|
|
ereport(FATAL,
|
|
/* translator: %s is a configuration file */
|
|
(errmsg("could not load %s", HbaFileName)));
|
|
}
|
|
if (!load_ident())
|
|
{
|
|
/*
|
|
* We can start up without the IDENT file, although it means that you
|
|
* cannot log in using any of the authentication methods that need a
|
|
* user name mapping. load_ident() already logged the details of error
|
|
* to the log.
|
|
*/
|
|
}
|
|
|
|
#ifdef HAVE_PTHREAD_IS_THREADED_NP
|
|
|
|
/*
|
|
* On macOS, libintl replaces setlocale() with a version that calls
|
|
* CFLocaleCopyCurrent() when its second argument is "" and every relevant
|
|
* environment variable is unset or empty. CFLocaleCopyCurrent() makes
|
|
* the process multithreaded. The postmaster calls sigprocmask() and
|
|
* calls fork() without an immediate exec(), both of which have undefined
|
|
* behavior in a multithreaded program. A multithreaded postmaster is the
|
|
* normal case on Windows, which offers neither fork() nor sigprocmask().
|
|
*/
|
|
if (pthread_is_threaded_np() != 0)
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("postmaster became multithreaded during startup"),
|
|
errhint("Set the LC_ALL environment variable to a valid locale.")));
|
|
#endif
|
|
|
|
/*
|
|
* Remember postmaster startup time
|
|
*/
|
|
PgStartTime = GetCurrentTimestamp();
|
|
|
|
/*
|
|
* Report postmaster status in the postmaster.pid file, to allow pg_ctl to
|
|
* see what's happening.
|
|
*/
|
|
AddToDataDirLockFile(LOCK_FILE_LINE_PM_STATUS, PM_STATUS_STARTING);
|
|
|
|
/* Start bgwriter and checkpointer so they can help with recovery */
|
|
if (CheckpointerPID == 0)
|
|
CheckpointerPID = StartChildProcess(B_CHECKPOINTER);
|
|
if (BgWriterPID == 0)
|
|
BgWriterPID = StartChildProcess(B_BG_WRITER);
|
|
|
|
/*
|
|
* We're ready to rock and roll...
|
|
*/
|
|
StartupPID = StartChildProcess(B_STARTUP);
|
|
Assert(StartupPID != 0);
|
|
StartupStatus = STARTUP_RUNNING;
|
|
pmState = PM_STARTUP;
|
|
|
|
/* Some workers may be scheduled to start now */
|
|
maybe_start_bgworkers();
|
|
|
|
status = ServerLoop();
|
|
|
|
/*
|
|
* ServerLoop probably shouldn't ever return, but if it does, close down.
|
|
*/
|
|
ExitPostmaster(status != STATUS_OK);
|
|
|
|
abort(); /* not reached */
|
|
}
|
|
|
|
|
|
/*
|
|
* on_proc_exit callback to close server's listen sockets
|
|
*/
|
|
static void
|
|
CloseServerPorts(int status, Datum arg)
|
|
{
|
|
int i;
|
|
|
|
/*
|
|
* First, explicitly close all the socket FDs. We used to just let this
|
|
* happen implicitly at postmaster exit, but it's better to close them
|
|
* before we remove the postmaster.pid lockfile; otherwise there's a race
|
|
* condition if a new postmaster wants to re-use the TCP port number.
|
|
*/
|
|
for (i = 0; i < NumListenSockets; i++)
|
|
{
|
|
if (closesocket(ListenSockets[i]) != 0)
|
|
elog(LOG, "could not close listen socket: %m");
|
|
}
|
|
NumListenSockets = 0;
|
|
|
|
/*
|
|
* Next, remove any filesystem entries for Unix sockets. To avoid race
|
|
* conditions against incoming postmasters, this must happen after closing
|
|
* the sockets and before removing lock files.
|
|
*/
|
|
RemoveSocketFiles();
|
|
|
|
/*
|
|
* We don't do anything about socket lock files here; those will be
|
|
* removed in a later on_proc_exit callback.
|
|
*/
|
|
}
|
|
|
|
/*
|
|
* on_proc_exit callback to delete external_pid_file
|
|
*/
|
|
static void
|
|
unlink_external_pid_file(int status, Datum arg)
|
|
{
|
|
if (external_pid_file)
|
|
unlink(external_pid_file);
|
|
}
|
|
|
|
|
|
/*
|
|
* Compute and check the directory paths to files that are part of the
|
|
* installation (as deduced from the postgres executable's own location)
|
|
*/
|
|
static void
|
|
getInstallationPaths(const char *argv0)
|
|
{
|
|
DIR *pdir;
|
|
|
|
/* Locate the postgres executable itself */
|
|
if (find_my_exec(argv0, my_exec_path) < 0)
|
|
ereport(FATAL,
|
|
(errmsg("%s: could not locate my own executable path", argv0)));
|
|
|
|
#ifdef EXEC_BACKEND
|
|
/* Locate executable backend before we change working directory */
|
|
if (find_other_exec(argv0, "postgres", PG_BACKEND_VERSIONSTR,
|
|
postgres_exec_path) < 0)
|
|
ereport(FATAL,
|
|
(errmsg("%s: could not locate matching postgres executable",
|
|
argv0)));
|
|
#endif
|
|
|
|
/*
|
|
* Locate the pkglib directory --- this has to be set early in case we try
|
|
* to load any modules from it in response to postgresql.conf entries.
|
|
*/
|
|
get_pkglib_path(my_exec_path, pkglib_path);
|
|
|
|
/*
|
|
* Verify that there's a readable directory there; otherwise the Postgres
|
|
* installation is incomplete or corrupt. (A typical cause of this
|
|
* failure is that the postgres executable has been moved or hardlinked to
|
|
* some directory that's not a sibling of the installation lib/
|
|
* directory.)
|
|
*/
|
|
pdir = AllocateDir(pkglib_path);
|
|
if (pdir == NULL)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not open directory \"%s\": %m",
|
|
pkglib_path),
|
|
errhint("This may indicate an incomplete PostgreSQL installation, or that the file \"%s\" has been moved away from its proper location.",
|
|
my_exec_path)));
|
|
FreeDir(pdir);
|
|
|
|
/*
|
|
* It's not worth checking the share/ directory. If the lib/ directory is
|
|
* there, then share/ probably is too.
|
|
*/
|
|
}
|
|
|
|
/*
|
|
* Check that pg_control exists in the correct location in the data directory.
|
|
*
|
|
* No attempt is made to validate the contents of pg_control here. This is
|
|
* just a sanity check to see if we are looking at a real data directory.
|
|
*/
|
|
static void
|
|
checkControlFile(void)
|
|
{
|
|
char path[MAXPGPATH];
|
|
FILE *fp;
|
|
|
|
snprintf(path, sizeof(path), "%s/global/pg_control", DataDir);
|
|
|
|
fp = AllocateFile(path, PG_BINARY_R);
|
|
if (fp == NULL)
|
|
{
|
|
write_stderr("%s: could not find the database system\n"
|
|
"Expected to find it in the directory \"%s\",\n"
|
|
"but could not open file \"%s\": %m\n",
|
|
progname, DataDir, path);
|
|
ExitPostmaster(2);
|
|
}
|
|
FreeFile(fp);
|
|
}
|
|
|
|
/*
|
|
* Determine how long should we let ServerLoop sleep, in milliseconds.
|
|
*
|
|
* In normal conditions we wait at most one minute, to ensure that the other
|
|
* background tasks handled by ServerLoop get done even when no requests are
|
|
* arriving. However, if there are background workers waiting to be started,
|
|
* we don't actually sleep so that they are quickly serviced. Other exception
|
|
* cases are as shown in the code.
|
|
*/
|
|
static int
|
|
DetermineSleepTime(void)
|
|
{
|
|
TimestampTz next_wakeup = 0;
|
|
|
|
/*
|
|
* Normal case: either there are no background workers at all, or we're in
|
|
* a shutdown sequence (during which we ignore bgworkers altogether).
|
|
*/
|
|
if (Shutdown > NoShutdown ||
|
|
(!StartWorkerNeeded && !HaveCrashedWorker))
|
|
{
|
|
if (AbortStartTime != 0)
|
|
{
|
|
int seconds;
|
|
|
|
/* time left to abort; clamp to 0 in case it already expired */
|
|
seconds = SIGKILL_CHILDREN_AFTER_SECS -
|
|
(time(NULL) - AbortStartTime);
|
|
|
|
return Max(seconds * 1000, 0);
|
|
}
|
|
else
|
|
return 60 * 1000;
|
|
}
|
|
|
|
if (StartWorkerNeeded)
|
|
return 0;
|
|
|
|
if (HaveCrashedWorker)
|
|
{
|
|
slist_mutable_iter siter;
|
|
|
|
/*
|
|
* When there are crashed bgworkers, we sleep just long enough that
|
|
* they are restarted when they request to be. Scan the list to
|
|
* determine the minimum of all wakeup times according to most recent
|
|
* crash time and requested restart interval.
|
|
*/
|
|
slist_foreach_modify(siter, &BackgroundWorkerList)
|
|
{
|
|
RegisteredBgWorker *rw;
|
|
TimestampTz this_wakeup;
|
|
|
|
rw = slist_container(RegisteredBgWorker, rw_lnode, siter.cur);
|
|
|
|
if (rw->rw_crashed_at == 0)
|
|
continue;
|
|
|
|
if (rw->rw_worker.bgw_restart_time == BGW_NEVER_RESTART
|
|
|| rw->rw_terminate)
|
|
{
|
|
ForgetBackgroundWorker(&siter);
|
|
continue;
|
|
}
|
|
|
|
this_wakeup = TimestampTzPlusMilliseconds(rw->rw_crashed_at,
|
|
1000L * rw->rw_worker.bgw_restart_time);
|
|
if (next_wakeup == 0 || this_wakeup < next_wakeup)
|
|
next_wakeup = this_wakeup;
|
|
}
|
|
}
|
|
|
|
if (next_wakeup != 0)
|
|
{
|
|
int ms;
|
|
|
|
/* result of TimestampDifferenceMilliseconds is in [0, INT_MAX] */
|
|
ms = (int) TimestampDifferenceMilliseconds(GetCurrentTimestamp(),
|
|
next_wakeup);
|
|
return Min(60 * 1000, ms);
|
|
}
|
|
|
|
return 60 * 1000;
|
|
}
|
|
|
|
/*
|
|
* Activate or deactivate notifications of server socket events. Since we
|
|
* don't currently have a way to remove events from an existing WaitEventSet,
|
|
* we'll just destroy and recreate the whole thing. This is called during
|
|
* shutdown so we can wait for backends to exit without accepting new
|
|
* connections, and during crash reinitialization when we need to start
|
|
* listening for new connections again. The WaitEventSet will be freed in fork
|
|
* children by ClosePostmasterPorts().
|
|
*/
|
|
static void
|
|
ConfigurePostmasterWaitSet(bool accept_connections)
|
|
{
|
|
if (pm_wait_set)
|
|
FreeWaitEventSet(pm_wait_set);
|
|
pm_wait_set = NULL;
|
|
|
|
pm_wait_set = CreateWaitEventSet(NULL,
|
|
accept_connections ? (1 + NumListenSockets) : 1);
|
|
AddWaitEventToSet(pm_wait_set, WL_LATCH_SET, PGINVALID_SOCKET, MyLatch,
|
|
NULL);
|
|
|
|
if (accept_connections)
|
|
{
|
|
for (int i = 0; i < NumListenSockets; i++)
|
|
AddWaitEventToSet(pm_wait_set, WL_SOCKET_ACCEPT, ListenSockets[i],
|
|
NULL, NULL);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Main idle loop of postmaster
|
|
*/
|
|
static int
|
|
ServerLoop(void)
|
|
{
|
|
time_t last_lockfile_recheck_time,
|
|
last_touch_time;
|
|
WaitEvent events[MAXLISTEN];
|
|
int nevents;
|
|
|
|
ConfigurePostmasterWaitSet(true);
|
|
last_lockfile_recheck_time = last_touch_time = time(NULL);
|
|
|
|
for (;;)
|
|
{
|
|
time_t now;
|
|
|
|
nevents = WaitEventSetWait(pm_wait_set,
|
|
DetermineSleepTime(),
|
|
events,
|
|
lengthof(events),
|
|
0 /* postmaster posts no wait_events */ );
|
|
|
|
/*
|
|
* Latch set by signal handler, or new connection pending on any of
|
|
* our sockets? If the latter, fork a child process to deal with it.
|
|
*/
|
|
for (int i = 0; i < nevents; i++)
|
|
{
|
|
if (events[i].events & WL_LATCH_SET)
|
|
ResetLatch(MyLatch);
|
|
|
|
/*
|
|
* The following requests are handled unconditionally, even if we
|
|
* didn't see WL_LATCH_SET. This gives high priority to shutdown
|
|
* and reload requests where the latch happens to appear later in
|
|
* events[] or will be reported by a later call to
|
|
* WaitEventSetWait().
|
|
*/
|
|
if (pending_pm_shutdown_request)
|
|
process_pm_shutdown_request();
|
|
if (pending_pm_reload_request)
|
|
process_pm_reload_request();
|
|
if (pending_pm_child_exit)
|
|
process_pm_child_exit();
|
|
if (pending_pm_pmsignal)
|
|
process_pm_pmsignal();
|
|
|
|
if (events[i].events & WL_SOCKET_ACCEPT)
|
|
{
|
|
ClientSocket s;
|
|
|
|
if (AcceptConnection(events[i].fd, &s) == STATUS_OK)
|
|
BackendStartup(&s);
|
|
|
|
/* We no longer need the open socket in this process */
|
|
if (s.sock != PGINVALID_SOCKET)
|
|
{
|
|
if (closesocket(s.sock) != 0)
|
|
elog(LOG, "could not close client socket: %m");
|
|
}
|
|
}
|
|
}
|
|
|
|
/* If we have lost the log collector, try to start a new one */
|
|
if (SysLoggerPID == 0 && Logging_collector)
|
|
SysLoggerPID = SysLogger_Start();
|
|
|
|
/*
|
|
* If no background writer process is running, and we are not in a
|
|
* state that prevents it, start one. It doesn't matter if this
|
|
* fails, we'll just try again later. Likewise for the checkpointer.
|
|
*/
|
|
if (pmState == PM_RUN || pmState == PM_RECOVERY ||
|
|
pmState == PM_HOT_STANDBY || pmState == PM_STARTUP)
|
|
{
|
|
if (CheckpointerPID == 0)
|
|
CheckpointerPID = StartChildProcess(B_CHECKPOINTER);
|
|
if (BgWriterPID == 0)
|
|
BgWriterPID = StartChildProcess(B_BG_WRITER);
|
|
}
|
|
|
|
/*
|
|
* Likewise, if we have lost the walwriter process, try to start a new
|
|
* one. But this is needed only in normal operation (else we cannot
|
|
* be writing any new WAL).
|
|
*/
|
|
if (WalWriterPID == 0 && pmState == PM_RUN)
|
|
WalWriterPID = StartChildProcess(B_WAL_WRITER);
|
|
|
|
/*
|
|
* If we have lost the autovacuum launcher, try to start a new one. We
|
|
* don't want autovacuum to run in binary upgrade mode because
|
|
* autovacuum might update relfrozenxid for empty tables before the
|
|
* physical files are put in place.
|
|
*/
|
|
if (!IsBinaryUpgrade && AutoVacPID == 0 &&
|
|
(AutoVacuumingActive() || start_autovac_launcher) &&
|
|
pmState == PM_RUN)
|
|
{
|
|
AutoVacPID = StartChildProcess(B_AUTOVAC_LAUNCHER);
|
|
if (AutoVacPID != 0)
|
|
start_autovac_launcher = false; /* signal processed */
|
|
}
|
|
|
|
/* If we have lost the archiver, try to start a new one. */
|
|
if (PgArchPID == 0 && PgArchStartupAllowed())
|
|
PgArchPID = StartChildProcess(B_ARCHIVER);
|
|
|
|
/* If we need to start a slot sync worker, try to do that now */
|
|
MaybeStartSlotSyncWorker();
|
|
|
|
/* If we need to signal the autovacuum launcher, do so now */
|
|
if (avlauncher_needs_signal)
|
|
{
|
|
avlauncher_needs_signal = false;
|
|
if (AutoVacPID != 0)
|
|
kill(AutoVacPID, SIGUSR2);
|
|
}
|
|
|
|
/* If we need to start a WAL receiver, try to do that now */
|
|
if (WalReceiverRequested)
|
|
MaybeStartWalReceiver();
|
|
|
|
/* If we need to start a WAL summarizer, try to do that now */
|
|
MaybeStartWalSummarizer();
|
|
|
|
/* Get other worker processes running, if needed */
|
|
if (StartWorkerNeeded || HaveCrashedWorker)
|
|
maybe_start_bgworkers();
|
|
|
|
#ifdef HAVE_PTHREAD_IS_THREADED_NP
|
|
|
|
/*
|
|
* With assertions enabled, check regularly for appearance of
|
|
* additional threads. All builds check at start and exit.
|
|
*/
|
|
Assert(pthread_is_threaded_np() == 0);
|
|
#endif
|
|
|
|
/*
|
|
* Lastly, check to see if it's time to do some things that we don't
|
|
* want to do every single time through the loop, because they're a
|
|
* bit expensive. Note that there's up to a minute of slop in when
|
|
* these tasks will be performed, since DetermineSleepTime() will let
|
|
* us sleep at most that long; except for SIGKILL timeout which has
|
|
* special-case logic there.
|
|
*/
|
|
now = time(NULL);
|
|
|
|
/*
|
|
* If we already sent SIGQUIT to children and they are slow to shut
|
|
* down, it's time to send them SIGKILL (or SIGABRT if requested).
|
|
* This doesn't happen normally, but under certain conditions backends
|
|
* can get stuck while shutting down. This is a last measure to get
|
|
* them unwedged.
|
|
*
|
|
* Note we also do this during recovery from a process crash.
|
|
*/
|
|
if ((Shutdown >= ImmediateShutdown || FatalError) &&
|
|
AbortStartTime != 0 &&
|
|
(now - AbortStartTime) >= SIGKILL_CHILDREN_AFTER_SECS)
|
|
{
|
|
/* We were gentle with them before. Not anymore */
|
|
ereport(LOG,
|
|
/* translator: %s is SIGKILL or SIGABRT */
|
|
(errmsg("issuing %s to recalcitrant children",
|
|
send_abort_for_kill ? "SIGABRT" : "SIGKILL")));
|
|
TerminateChildren(send_abort_for_kill ? SIGABRT : SIGKILL);
|
|
/* reset flag so we don't SIGKILL again */
|
|
AbortStartTime = 0;
|
|
}
|
|
|
|
/*
|
|
* Once a minute, verify that postmaster.pid hasn't been removed or
|
|
* overwritten. If it has, we force a shutdown. This avoids having
|
|
* postmasters and child processes hanging around after their database
|
|
* is gone, and maybe causing problems if a new database cluster is
|
|
* created in the same place. It also provides some protection
|
|
* against a DBA foolishly removing postmaster.pid and manually
|
|
* starting a new postmaster. Data corruption is likely to ensue from
|
|
* that anyway, but we can minimize the damage by aborting ASAP.
|
|
*/
|
|
if (now - last_lockfile_recheck_time >= 1 * SECS_PER_MINUTE)
|
|
{
|
|
if (!RecheckDataDirLockFile())
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("performing immediate shutdown because data directory lock file is invalid")));
|
|
kill(MyProcPid, SIGQUIT);
|
|
}
|
|
last_lockfile_recheck_time = now;
|
|
}
|
|
|
|
/*
|
|
* Touch Unix socket and lock files every 58 minutes, to ensure that
|
|
* they are not removed by overzealous /tmp-cleaning tasks. We assume
|
|
* no one runs cleaners with cutoff times of less than an hour ...
|
|
*/
|
|
if (now - last_touch_time >= 58 * SECS_PER_MINUTE)
|
|
{
|
|
TouchSocketFiles();
|
|
TouchSocketLockFiles();
|
|
last_touch_time = now;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Read a client's startup packet and do something according to it.
|
|
*
|
|
* Returns STATUS_OK or STATUS_ERROR, or might call ereport(FATAL) and
|
|
* not return at all.
|
|
*
|
|
* (Note that ereport(FATAL) stuff is sent to the client, so only use it
|
|
* if that's what you want. Return STATUS_ERROR if you don't want to
|
|
* send anything to the client, which would typically be appropriate
|
|
* if we detect a communications failure.)
|
|
*
|
|
* Set ssl_done and/or gss_done when negotiation of an encrypted layer
|
|
* (currently, TLS or GSSAPI) is completed. A successful negotiation of either
|
|
* encryption layer sets both flags, but a rejected negotiation sets only the
|
|
* flag for that layer, since the client may wish to try the other one. We
|
|
* should make no assumption here about the order in which the client may make
|
|
* requests.
|
|
*/
|
|
static int
|
|
ProcessStartupPacket(Port *port, bool ssl_done, bool gss_done)
|
|
{
|
|
int32 len;
|
|
char *buf;
|
|
ProtocolVersion proto;
|
|
MemoryContext oldcontext;
|
|
|
|
pq_startmsgread();
|
|
|
|
/*
|
|
* Grab the first byte of the length word separately, so that we can tell
|
|
* whether we have no data at all or an incomplete packet. (This might
|
|
* sound inefficient, but it's not really, because of buffering in
|
|
* pqcomm.c.)
|
|
*/
|
|
if (pq_getbytes((char *) &len, 1) == EOF)
|
|
{
|
|
/*
|
|
* If we get no data at all, don't clutter the log with a complaint;
|
|
* such cases often occur for legitimate reasons. An example is that
|
|
* we might be here after responding to NEGOTIATE_SSL_CODE, and if the
|
|
* client didn't like our response, it'll probably just drop the
|
|
* connection. Service-monitoring software also often just opens and
|
|
* closes a connection without sending anything. (So do port
|
|
* scanners, which may be less benign, but it's not really our job to
|
|
* notice those.)
|
|
*/
|
|
return STATUS_ERROR;
|
|
}
|
|
|
|
if (pq_getbytes(((char *) &len) + 1, 3) == EOF)
|
|
{
|
|
/* Got a partial length word, so bleat about that */
|
|
if (!ssl_done && !gss_done)
|
|
ereport(COMMERROR,
|
|
(errcode(ERRCODE_PROTOCOL_VIOLATION),
|
|
errmsg("incomplete startup packet")));
|
|
return STATUS_ERROR;
|
|
}
|
|
|
|
len = pg_ntoh32(len);
|
|
len -= 4;
|
|
|
|
if (len < (int32) sizeof(ProtocolVersion) ||
|
|
len > MAX_STARTUP_PACKET_LENGTH)
|
|
{
|
|
ereport(COMMERROR,
|
|
(errcode(ERRCODE_PROTOCOL_VIOLATION),
|
|
errmsg("invalid length of startup packet")));
|
|
return STATUS_ERROR;
|
|
}
|
|
|
|
/*
|
|
* Allocate space to hold the startup packet, plus one extra byte that's
|
|
* initialized to be zero. This ensures we will have null termination of
|
|
* all strings inside the packet.
|
|
*/
|
|
buf = palloc(len + 1);
|
|
buf[len] = '\0';
|
|
|
|
if (pq_getbytes(buf, len) == EOF)
|
|
{
|
|
ereport(COMMERROR,
|
|
(errcode(ERRCODE_PROTOCOL_VIOLATION),
|
|
errmsg("incomplete startup packet")));
|
|
return STATUS_ERROR;
|
|
}
|
|
pq_endmsgread();
|
|
|
|
/*
|
|
* The first field is either a protocol version number or a special
|
|
* request code.
|
|
*/
|
|
port->proto = proto = pg_ntoh32(*((ProtocolVersion *) buf));
|
|
|
|
if (proto == CANCEL_REQUEST_CODE)
|
|
{
|
|
if (len != sizeof(CancelRequestPacket))
|
|
{
|
|
ereport(COMMERROR,
|
|
(errcode(ERRCODE_PROTOCOL_VIOLATION),
|
|
errmsg("invalid length of startup packet")));
|
|
return STATUS_ERROR;
|
|
}
|
|
processCancelRequest(port, buf);
|
|
/* Not really an error, but we don't want to proceed further */
|
|
return STATUS_ERROR;
|
|
}
|
|
|
|
if (proto == NEGOTIATE_SSL_CODE && !ssl_done)
|
|
{
|
|
char SSLok;
|
|
|
|
#ifdef USE_SSL
|
|
/* No SSL when disabled or on Unix sockets */
|
|
if (!LoadedSSL || port->laddr.addr.ss_family == AF_UNIX)
|
|
SSLok = 'N';
|
|
else
|
|
SSLok = 'S'; /* Support for SSL */
|
|
#else
|
|
SSLok = 'N'; /* No support for SSL */
|
|
#endif
|
|
|
|
retry1:
|
|
if (send(port->sock, &SSLok, 1, 0) != 1)
|
|
{
|
|
if (errno == EINTR)
|
|
goto retry1; /* if interrupted, just retry */
|
|
ereport(COMMERROR,
|
|
(errcode_for_socket_access(),
|
|
errmsg("failed to send SSL negotiation response: %m")));
|
|
return STATUS_ERROR; /* close the connection */
|
|
}
|
|
|
|
#ifdef USE_SSL
|
|
if (SSLok == 'S' && secure_open_server(port) == -1)
|
|
return STATUS_ERROR;
|
|
#endif
|
|
|
|
/*
|
|
* At this point we should have no data already buffered. If we do,
|
|
* it was received before we performed the SSL handshake, so it wasn't
|
|
* encrypted and indeed may have been injected by a man-in-the-middle.
|
|
* We report this case to the client.
|
|
*/
|
|
if (pq_buffer_has_data())
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_PROTOCOL_VIOLATION),
|
|
errmsg("received unencrypted data after SSL request"),
|
|
errdetail("This could be either a client-software bug or evidence of an attempted man-in-the-middle attack.")));
|
|
|
|
/*
|
|
* regular startup packet, cancel, etc packet should follow, but not
|
|
* another SSL negotiation request, and a GSS request should only
|
|
* follow if SSL was rejected (client may negotiate in either order)
|
|
*/
|
|
return ProcessStartupPacket(port, true, SSLok == 'S');
|
|
}
|
|
else if (proto == NEGOTIATE_GSS_CODE && !gss_done)
|
|
{
|
|
char GSSok = 'N';
|
|
|
|
#ifdef ENABLE_GSS
|
|
/* No GSSAPI encryption when on Unix socket */
|
|
if (port->laddr.addr.ss_family != AF_UNIX)
|
|
GSSok = 'G';
|
|
#endif
|
|
|
|
while (send(port->sock, &GSSok, 1, 0) != 1)
|
|
{
|
|
if (errno == EINTR)
|
|
continue;
|
|
ereport(COMMERROR,
|
|
(errcode_for_socket_access(),
|
|
errmsg("failed to send GSSAPI negotiation response: %m")));
|
|
return STATUS_ERROR; /* close the connection */
|
|
}
|
|
|
|
#ifdef ENABLE_GSS
|
|
if (GSSok == 'G' && secure_open_gssapi(port) == -1)
|
|
return STATUS_ERROR;
|
|
#endif
|
|
|
|
/*
|
|
* At this point we should have no data already buffered. If we do,
|
|
* it was received before we performed the GSS handshake, so it wasn't
|
|
* encrypted and indeed may have been injected by a man-in-the-middle.
|
|
* We report this case to the client.
|
|
*/
|
|
if (pq_buffer_has_data())
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_PROTOCOL_VIOLATION),
|
|
errmsg("received unencrypted data after GSSAPI encryption request"),
|
|
errdetail("This could be either a client-software bug or evidence of an attempted man-in-the-middle attack.")));
|
|
|
|
/*
|
|
* regular startup packet, cancel, etc packet should follow, but not
|
|
* another GSS negotiation request, and an SSL request should only
|
|
* follow if GSS was rejected (client may negotiate in either order)
|
|
*/
|
|
return ProcessStartupPacket(port, GSSok == 'G', true);
|
|
}
|
|
|
|
/* Could add additional special packet types here */
|
|
|
|
/*
|
|
* Set FrontendProtocol now so that ereport() knows what format to send if
|
|
* we fail during startup.
|
|
*/
|
|
FrontendProtocol = proto;
|
|
|
|
/* Check that the major protocol version is in range. */
|
|
if (PG_PROTOCOL_MAJOR(proto) < PG_PROTOCOL_MAJOR(PG_PROTOCOL_EARLIEST) ||
|
|
PG_PROTOCOL_MAJOR(proto) > PG_PROTOCOL_MAJOR(PG_PROTOCOL_LATEST))
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
|
|
errmsg("unsupported frontend protocol %u.%u: server supports %u.0 to %u.%u",
|
|
PG_PROTOCOL_MAJOR(proto), PG_PROTOCOL_MINOR(proto),
|
|
PG_PROTOCOL_MAJOR(PG_PROTOCOL_EARLIEST),
|
|
PG_PROTOCOL_MAJOR(PG_PROTOCOL_LATEST),
|
|
PG_PROTOCOL_MINOR(PG_PROTOCOL_LATEST))));
|
|
|
|
/*
|
|
* Now fetch parameters out of startup packet and save them into the Port
|
|
* structure.
|
|
*/
|
|
oldcontext = MemoryContextSwitchTo(TopMemoryContext);
|
|
|
|
/* Handle protocol version 3 startup packet */
|
|
{
|
|
int32 offset = sizeof(ProtocolVersion);
|
|
List *unrecognized_protocol_options = NIL;
|
|
|
|
/*
|
|
* Scan packet body for name/option pairs. We can assume any string
|
|
* beginning within the packet body is null-terminated, thanks to
|
|
* zeroing extra byte above.
|
|
*/
|
|
port->guc_options = NIL;
|
|
|
|
while (offset < len)
|
|
{
|
|
char *nameptr = buf + offset;
|
|
int32 valoffset;
|
|
char *valptr;
|
|
|
|
if (*nameptr == '\0')
|
|
break; /* found packet terminator */
|
|
valoffset = offset + strlen(nameptr) + 1;
|
|
if (valoffset >= len)
|
|
break; /* missing value, will complain below */
|
|
valptr = buf + valoffset;
|
|
|
|
if (strcmp(nameptr, "database") == 0)
|
|
port->database_name = pstrdup(valptr);
|
|
else if (strcmp(nameptr, "user") == 0)
|
|
port->user_name = pstrdup(valptr);
|
|
else if (strcmp(nameptr, "options") == 0)
|
|
port->cmdline_options = pstrdup(valptr);
|
|
else if (strcmp(nameptr, "replication") == 0)
|
|
{
|
|
/*
|
|
* Due to backward compatibility concerns the replication
|
|
* parameter is a hybrid beast which allows the value to be
|
|
* either boolean or the string 'database'. The latter
|
|
* connects to a specific database which is e.g. required for
|
|
* logical decoding while.
|
|
*/
|
|
if (strcmp(valptr, "database") == 0)
|
|
{
|
|
am_walsender = true;
|
|
am_db_walsender = true;
|
|
}
|
|
else if (!parse_bool(valptr, &am_walsender))
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
|
|
errmsg("invalid value for parameter \"%s\": \"%s\"",
|
|
"replication",
|
|
valptr),
|
|
errhint("Valid values are: \"false\", 0, \"true\", 1, \"database\".")));
|
|
}
|
|
else if (strncmp(nameptr, "_pq_.", 5) == 0)
|
|
{
|
|
/*
|
|
* Any option beginning with _pq_. is reserved for use as a
|
|
* protocol-level option, but at present no such options are
|
|
* defined.
|
|
*/
|
|
unrecognized_protocol_options =
|
|
lappend(unrecognized_protocol_options, pstrdup(nameptr));
|
|
}
|
|
else
|
|
{
|
|
/* Assume it's a generic GUC option */
|
|
port->guc_options = lappend(port->guc_options,
|
|
pstrdup(nameptr));
|
|
port->guc_options = lappend(port->guc_options,
|
|
pstrdup(valptr));
|
|
|
|
/*
|
|
* Copy application_name to port if we come across it. This
|
|
* is done so we can log the application_name in the
|
|
* connection authorization message. Note that the GUC would
|
|
* be used but we haven't gone through GUC setup yet.
|
|
*/
|
|
if (strcmp(nameptr, "application_name") == 0)
|
|
{
|
|
port->application_name = pg_clean_ascii(valptr, 0);
|
|
}
|
|
}
|
|
offset = valoffset + strlen(valptr) + 1;
|
|
}
|
|
|
|
/*
|
|
* If we didn't find a packet terminator exactly at the end of the
|
|
* given packet length, complain.
|
|
*/
|
|
if (offset != len - 1)
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_PROTOCOL_VIOLATION),
|
|
errmsg("invalid startup packet layout: expected terminator as last byte")));
|
|
|
|
/*
|
|
* If the client requested a newer protocol version or if the client
|
|
* requested any protocol options we didn't recognize, let them know
|
|
* the newest minor protocol version we do support and the names of
|
|
* any unrecognized options.
|
|
*/
|
|
if (PG_PROTOCOL_MINOR(proto) > PG_PROTOCOL_MINOR(PG_PROTOCOL_LATEST) ||
|
|
unrecognized_protocol_options != NIL)
|
|
SendNegotiateProtocolVersion(unrecognized_protocol_options);
|
|
}
|
|
|
|
/* Check a user name was given. */
|
|
if (port->user_name == NULL || port->user_name[0] == '\0')
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
|
|
errmsg("no PostgreSQL user name specified in startup packet")));
|
|
|
|
/* The database defaults to the user name. */
|
|
if (port->database_name == NULL || port->database_name[0] == '\0')
|
|
port->database_name = pstrdup(port->user_name);
|
|
|
|
if (am_walsender)
|
|
MyBackendType = B_WAL_SENDER;
|
|
else
|
|
MyBackendType = B_BACKEND;
|
|
|
|
/*
|
|
* Normal walsender backends, e.g. for streaming replication, are not
|
|
* connected to a particular database. But walsenders used for logical
|
|
* replication need to connect to a specific database. We allow streaming
|
|
* replication commands to be issued even if connected to a database as it
|
|
* can make sense to first make a basebackup and then stream changes
|
|
* starting from that.
|
|
*/
|
|
if (am_walsender && !am_db_walsender)
|
|
port->database_name[0] = '\0';
|
|
|
|
/*
|
|
* Done filling the Port structure
|
|
*/
|
|
MemoryContextSwitchTo(oldcontext);
|
|
|
|
return STATUS_OK;
|
|
}
|
|
|
|
/*
|
|
* Send a NegotiateProtocolVersion to the client. This lets the client know
|
|
* that they have requested a newer minor protocol version than we are able
|
|
* to speak. We'll speak the highest version we know about; the client can,
|
|
* of course, abandon the connection if that's a problem.
|
|
*
|
|
* We also include in the response a list of protocol options we didn't
|
|
* understand. This allows clients to include optional parameters that might
|
|
* be present either in newer protocol versions or third-party protocol
|
|
* extensions without fear of having to reconnect if those options are not
|
|
* understood, while at the same time making certain that the client is aware
|
|
* of which options were actually accepted.
|
|
*/
|
|
static void
|
|
SendNegotiateProtocolVersion(List *unrecognized_protocol_options)
|
|
{
|
|
StringInfoData buf;
|
|
ListCell *lc;
|
|
|
|
pq_beginmessage(&buf, PqMsg_NegotiateProtocolVersion);
|
|
pq_sendint32(&buf, PG_PROTOCOL_LATEST);
|
|
pq_sendint32(&buf, list_length(unrecognized_protocol_options));
|
|
foreach(lc, unrecognized_protocol_options)
|
|
pq_sendstring(&buf, lfirst(lc));
|
|
pq_endmessage(&buf);
|
|
|
|
/* no need to flush, some other message will follow */
|
|
}
|
|
|
|
/*
|
|
* The client has sent a cancel request packet, not a normal
|
|
* start-a-new-connection packet. Perform the necessary processing.
|
|
* Nothing is sent back to the client.
|
|
*/
|
|
static void
|
|
processCancelRequest(Port *port, void *pkt)
|
|
{
|
|
CancelRequestPacket *canc = (CancelRequestPacket *) pkt;
|
|
int backendPID;
|
|
int32 cancelAuthCode;
|
|
Backend *bp;
|
|
|
|
#ifndef EXEC_BACKEND
|
|
dlist_iter iter;
|
|
#else
|
|
int i;
|
|
#endif
|
|
|
|
backendPID = (int) pg_ntoh32(canc->backendPID);
|
|
cancelAuthCode = (int32) pg_ntoh32(canc->cancelAuthCode);
|
|
|
|
/*
|
|
* See if we have a matching backend. In the EXEC_BACKEND case, we can no
|
|
* longer access the postmaster's own backend list, and must rely on the
|
|
* duplicate array in shared memory.
|
|
*/
|
|
#ifndef EXEC_BACKEND
|
|
dlist_foreach(iter, &BackendList)
|
|
{
|
|
bp = dlist_container(Backend, elem, iter.cur);
|
|
#else
|
|
for (i = MaxLivePostmasterChildren() - 1; i >= 0; i--)
|
|
{
|
|
bp = (Backend *) &ShmemBackendArray[i];
|
|
#endif
|
|
if (bp->pid == backendPID)
|
|
{
|
|
if (bp->cancel_key == cancelAuthCode)
|
|
{
|
|
/* Found a match; signal that backend to cancel current op */
|
|
ereport(DEBUG2,
|
|
(errmsg_internal("processing cancel request: sending SIGINT to process %d",
|
|
backendPID)));
|
|
signal_child(bp->pid, SIGINT);
|
|
}
|
|
else
|
|
/* Right PID, wrong key: no way, Jose */
|
|
ereport(LOG,
|
|
(errmsg("wrong key in cancel request for process %d",
|
|
backendPID)));
|
|
return;
|
|
}
|
|
#ifndef EXEC_BACKEND /* make GNU Emacs 26.1 see brace balance */
|
|
}
|
|
#else
|
|
}
|
|
#endif
|
|
|
|
/* No matching backend */
|
|
ereport(LOG,
|
|
(errmsg("PID %d in cancel request did not match any process",
|
|
backendPID)));
|
|
}
|
|
|
|
/*
|
|
* canAcceptConnections --- check to see if database state allows connections
|
|
* of the specified type. backend_type can be BACKEND_TYPE_NORMAL,
|
|
* BACKEND_TYPE_AUTOVAC, or BACKEND_TYPE_BGWORKER. (Note that we don't yet
|
|
* know whether a NORMAL connection might turn into a walsender.)
|
|
*/
|
|
static CAC_state
|
|
canAcceptConnections(int backend_type)
|
|
{
|
|
CAC_state result = CAC_OK;
|
|
|
|
/*
|
|
* Can't start backends when in startup/shutdown/inconsistent recovery
|
|
* state. We treat autovac workers the same as user backends for this
|
|
* purpose. However, bgworkers are excluded from this test; we expect
|
|
* bgworker_should_start_now() decided whether the DB state allows them.
|
|
*/
|
|
if (pmState != PM_RUN && pmState != PM_HOT_STANDBY &&
|
|
backend_type != BACKEND_TYPE_BGWORKER)
|
|
{
|
|
if (Shutdown > NoShutdown)
|
|
return CAC_SHUTDOWN; /* shutdown is pending */
|
|
else if (!FatalError && pmState == PM_STARTUP)
|
|
return CAC_STARTUP; /* normal startup */
|
|
else if (!FatalError && pmState == PM_RECOVERY)
|
|
return CAC_NOTCONSISTENT; /* not yet at consistent recovery
|
|
* state */
|
|
else
|
|
return CAC_RECOVERY; /* else must be crash recovery */
|
|
}
|
|
|
|
/*
|
|
* "Smart shutdown" restrictions are applied only to normal connections,
|
|
* not to autovac workers or bgworkers.
|
|
*/
|
|
if (!connsAllowed && backend_type == BACKEND_TYPE_NORMAL)
|
|
return CAC_SHUTDOWN; /* shutdown is pending */
|
|
|
|
/*
|
|
* Don't start too many children.
|
|
*
|
|
* We allow more connections here than we can have backends because some
|
|
* might still be authenticating; they might fail auth, or some existing
|
|
* backend might exit before the auth cycle is completed. The exact
|
|
* MaxBackends limit is enforced when a new backend tries to join the
|
|
* shared-inval backend array.
|
|
*
|
|
* The limit here must match the sizes of the per-child-process arrays;
|
|
* see comments for MaxLivePostmasterChildren().
|
|
*/
|
|
if (CountChildren(BACKEND_TYPE_ALL) >= MaxLivePostmasterChildren())
|
|
result = CAC_TOOMANY;
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* ClosePostmasterPorts -- close all the postmaster's open sockets
|
|
*
|
|
* This is called during child process startup to release file descriptors
|
|
* that are not needed by that child process. The postmaster still has
|
|
* them open, of course.
|
|
*
|
|
* Note: we pass am_syslogger as a boolean because we don't want to set
|
|
* the global variable yet when this is called.
|
|
*/
|
|
void
|
|
ClosePostmasterPorts(bool am_syslogger)
|
|
{
|
|
/* Release resources held by the postmaster's WaitEventSet. */
|
|
if (pm_wait_set)
|
|
{
|
|
FreeWaitEventSetAfterFork(pm_wait_set);
|
|
pm_wait_set = NULL;
|
|
}
|
|
|
|
#ifndef WIN32
|
|
|
|
/*
|
|
* Close the write end of postmaster death watch pipe. It's important to
|
|
* do this as early as possible, so that if postmaster dies, others won't
|
|
* think that it's still running because we're holding the pipe open.
|
|
*/
|
|
if (close(postmaster_alive_fds[POSTMASTER_FD_OWN]) != 0)
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg_internal("could not close postmaster death monitoring pipe in child process: %m")));
|
|
postmaster_alive_fds[POSTMASTER_FD_OWN] = -1;
|
|
/* Notify fd.c that we released one pipe FD. */
|
|
ReleaseExternalFD();
|
|
#endif
|
|
|
|
/*
|
|
* Close the postmaster's listen sockets. These aren't tracked by fd.c,
|
|
* so we don't call ReleaseExternalFD() here.
|
|
*
|
|
* The listen sockets are marked as FD_CLOEXEC, so this isn't needed in
|
|
* EXEC_BACKEND mode.
|
|
*/
|
|
#ifndef EXEC_BACKEND
|
|
if (ListenSockets)
|
|
{
|
|
for (int i = 0; i < NumListenSockets; i++)
|
|
{
|
|
if (closesocket(ListenSockets[i]) != 0)
|
|
elog(LOG, "could not close listen socket: %m");
|
|
}
|
|
pfree(ListenSockets);
|
|
}
|
|
NumListenSockets = 0;
|
|
ListenSockets = NULL;
|
|
#endif
|
|
|
|
/*
|
|
* If using syslogger, close the read side of the pipe. We don't bother
|
|
* tracking this in fd.c, either.
|
|
*/
|
|
if (!am_syslogger)
|
|
{
|
|
#ifndef WIN32
|
|
if (syslogPipe[0] >= 0)
|
|
close(syslogPipe[0]);
|
|
syslogPipe[0] = -1;
|
|
#else
|
|
if (syslogPipe[0])
|
|
CloseHandle(syslogPipe[0]);
|
|
syslogPipe[0] = 0;
|
|
#endif
|
|
}
|
|
|
|
#ifdef USE_BONJOUR
|
|
/* If using Bonjour, close the connection to the mDNS daemon */
|
|
if (bonjour_sdref)
|
|
close(DNSServiceRefSockFD(bonjour_sdref));
|
|
#endif
|
|
}
|
|
|
|
|
|
/*
|
|
* InitProcessGlobals -- set MyProcPid, MyStartTime[stamp], random seeds
|
|
*
|
|
* Called early in the postmaster and every backend.
|
|
*/
|
|
void
|
|
InitProcessGlobals(void)
|
|
{
|
|
MyProcPid = getpid();
|
|
MyStartTimestamp = GetCurrentTimestamp();
|
|
MyStartTime = timestamptz_to_time_t(MyStartTimestamp);
|
|
|
|
/*
|
|
* Set a different global seed in every process. We want something
|
|
* unpredictable, so if possible, use high-quality random bits for the
|
|
* seed. Otherwise, fall back to a seed based on timestamp and PID.
|
|
*/
|
|
if (unlikely(!pg_prng_strong_seed(&pg_global_prng_state)))
|
|
{
|
|
uint64 rseed;
|
|
|
|
/*
|
|
* Since PIDs and timestamps tend to change more frequently in their
|
|
* least significant bits, shift the timestamp left to allow a larger
|
|
* total number of seeds in a given time period. Since that would
|
|
* leave only 20 bits of the timestamp that cycle every ~1 second,
|
|
* also mix in some higher bits.
|
|
*/
|
|
rseed = ((uint64) MyProcPid) ^
|
|
((uint64) MyStartTimestamp << 12) ^
|
|
((uint64) MyStartTimestamp >> 20);
|
|
|
|
pg_prng_seed(&pg_global_prng_state, rseed);
|
|
}
|
|
|
|
/*
|
|
* Also make sure that we've set a good seed for random(3). Use of that
|
|
* is deprecated in core Postgres, but extensions might use it.
|
|
*/
|
|
#ifndef WIN32
|
|
srandom(pg_prng_uint32(&pg_global_prng_state));
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Child processes use SIGUSR1 to notify us of 'pmsignals'. pg_ctl uses
|
|
* SIGUSR1 to ask postmaster to check for logrotate and promote files.
|
|
*/
|
|
static void
|
|
handle_pm_pmsignal_signal(SIGNAL_ARGS)
|
|
{
|
|
pending_pm_pmsignal = true;
|
|
SetLatch(MyLatch);
|
|
}
|
|
|
|
/*
|
|
* pg_ctl uses SIGHUP to request a reload of the configuration files.
|
|
*/
|
|
static void
|
|
handle_pm_reload_request_signal(SIGNAL_ARGS)
|
|
{
|
|
pending_pm_reload_request = true;
|
|
SetLatch(MyLatch);
|
|
}
|
|
|
|
/*
|
|
* Re-read config files, and tell children to do same.
|
|
*/
|
|
static void
|
|
process_pm_reload_request(void)
|
|
{
|
|
pending_pm_reload_request = false;
|
|
|
|
ereport(DEBUG2,
|
|
(errmsg_internal("postmaster received reload request signal")));
|
|
|
|
if (Shutdown <= SmartShutdown)
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("received SIGHUP, reloading configuration files")));
|
|
ProcessConfigFile(PGC_SIGHUP);
|
|
SignalChildren(SIGHUP);
|
|
if (StartupPID != 0)
|
|
signal_child(StartupPID, SIGHUP);
|
|
if (BgWriterPID != 0)
|
|
signal_child(BgWriterPID, SIGHUP);
|
|
if (CheckpointerPID != 0)
|
|
signal_child(CheckpointerPID, SIGHUP);
|
|
if (WalWriterPID != 0)
|
|
signal_child(WalWriterPID, SIGHUP);
|
|
if (WalReceiverPID != 0)
|
|
signal_child(WalReceiverPID, SIGHUP);
|
|
if (WalSummarizerPID != 0)
|
|
signal_child(WalSummarizerPID, SIGHUP);
|
|
if (AutoVacPID != 0)
|
|
signal_child(AutoVacPID, SIGHUP);
|
|
if (PgArchPID != 0)
|
|
signal_child(PgArchPID, SIGHUP);
|
|
if (SysLoggerPID != 0)
|
|
signal_child(SysLoggerPID, SIGHUP);
|
|
if (SlotSyncWorkerPID != 0)
|
|
signal_child(SlotSyncWorkerPID, SIGHUP);
|
|
|
|
/* Reload authentication config files too */
|
|
if (!load_hba())
|
|
ereport(LOG,
|
|
/* translator: %s is a configuration file */
|
|
(errmsg("%s was not reloaded", HbaFileName)));
|
|
|
|
if (!load_ident())
|
|
ereport(LOG,
|
|
(errmsg("%s was not reloaded", IdentFileName)));
|
|
|
|
#ifdef USE_SSL
|
|
/* Reload SSL configuration as well */
|
|
if (EnableSSL)
|
|
{
|
|
if (secure_initialize(false) == 0)
|
|
LoadedSSL = true;
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("SSL configuration was not reloaded")));
|
|
}
|
|
else
|
|
{
|
|
secure_destroy();
|
|
LoadedSSL = false;
|
|
}
|
|
#endif
|
|
|
|
#ifdef EXEC_BACKEND
|
|
/* Update the starting-point file for future children */
|
|
write_nondefault_variables(PGC_SIGHUP);
|
|
#endif
|
|
}
|
|
}
|
|
|
|
/*
|
|
* pg_ctl uses SIGTERM, SIGINT and SIGQUIT to request different types of
|
|
* shutdown.
|
|
*/
|
|
static void
|
|
handle_pm_shutdown_request_signal(SIGNAL_ARGS)
|
|
{
|
|
switch (postgres_signal_arg)
|
|
{
|
|
case SIGTERM:
|
|
/* smart is implied if the other two flags aren't set */
|
|
pending_pm_shutdown_request = true;
|
|
break;
|
|
case SIGINT:
|
|
pending_pm_fast_shutdown_request = true;
|
|
pending_pm_shutdown_request = true;
|
|
break;
|
|
case SIGQUIT:
|
|
pending_pm_immediate_shutdown_request = true;
|
|
pending_pm_shutdown_request = true;
|
|
break;
|
|
}
|
|
SetLatch(MyLatch);
|
|
}
|
|
|
|
/*
|
|
* Process shutdown request.
|
|
*/
|
|
static void
|
|
process_pm_shutdown_request(void)
|
|
{
|
|
int mode;
|
|
|
|
ereport(DEBUG2,
|
|
(errmsg_internal("postmaster received shutdown request signal")));
|
|
|
|
pending_pm_shutdown_request = false;
|
|
|
|
/*
|
|
* If more than one shutdown request signal arrived since the last server
|
|
* loop, take the one that is the most immediate. That matches the
|
|
* priority that would apply if we processed them one by one in any order.
|
|
*/
|
|
if (pending_pm_immediate_shutdown_request)
|
|
{
|
|
pending_pm_immediate_shutdown_request = false;
|
|
pending_pm_fast_shutdown_request = false;
|
|
mode = ImmediateShutdown;
|
|
}
|
|
else if (pending_pm_fast_shutdown_request)
|
|
{
|
|
pending_pm_fast_shutdown_request = false;
|
|
mode = FastShutdown;
|
|
}
|
|
else
|
|
mode = SmartShutdown;
|
|
|
|
switch (mode)
|
|
{
|
|
case SmartShutdown:
|
|
|
|
/*
|
|
* Smart Shutdown:
|
|
*
|
|
* Wait for children to end their work, then shut down.
|
|
*/
|
|
if (Shutdown >= SmartShutdown)
|
|
break;
|
|
Shutdown = SmartShutdown;
|
|
ereport(LOG,
|
|
(errmsg("received smart shutdown request")));
|
|
|
|
/* Report status */
|
|
AddToDataDirLockFile(LOCK_FILE_LINE_PM_STATUS, PM_STATUS_STOPPING);
|
|
#ifdef USE_SYSTEMD
|
|
sd_notify(0, "STOPPING=1");
|
|
#endif
|
|
|
|
/*
|
|
* If we reached normal running, we go straight to waiting for
|
|
* client backends to exit. If already in PM_STOP_BACKENDS or a
|
|
* later state, do not change it.
|
|
*/
|
|
if (pmState == PM_RUN || pmState == PM_HOT_STANDBY)
|
|
connsAllowed = false;
|
|
else if (pmState == PM_STARTUP || pmState == PM_RECOVERY)
|
|
{
|
|
/* There should be no clients, so proceed to stop children */
|
|
pmState = PM_STOP_BACKENDS;
|
|
}
|
|
|
|
/*
|
|
* Now wait for online backup mode to end and backends to exit. If
|
|
* that is already the case, PostmasterStateMachine will take the
|
|
* next step.
|
|
*/
|
|
PostmasterStateMachine();
|
|
break;
|
|
|
|
case FastShutdown:
|
|
|
|
/*
|
|
* Fast Shutdown:
|
|
*
|
|
* Abort all children with SIGTERM (rollback active transactions
|
|
* and exit) and shut down when they are gone.
|
|
*/
|
|
if (Shutdown >= FastShutdown)
|
|
break;
|
|
Shutdown = FastShutdown;
|
|
ereport(LOG,
|
|
(errmsg("received fast shutdown request")));
|
|
|
|
/* Report status */
|
|
AddToDataDirLockFile(LOCK_FILE_LINE_PM_STATUS, PM_STATUS_STOPPING);
|
|
#ifdef USE_SYSTEMD
|
|
sd_notify(0, "STOPPING=1");
|
|
#endif
|
|
|
|
if (pmState == PM_STARTUP || pmState == PM_RECOVERY)
|
|
{
|
|
/* Just shut down background processes silently */
|
|
pmState = PM_STOP_BACKENDS;
|
|
}
|
|
else if (pmState == PM_RUN ||
|
|
pmState == PM_HOT_STANDBY)
|
|
{
|
|
/* Report that we're about to zap live client sessions */
|
|
ereport(LOG,
|
|
(errmsg("aborting any active transactions")));
|
|
pmState = PM_STOP_BACKENDS;
|
|
}
|
|
|
|
/*
|
|
* PostmasterStateMachine will issue any necessary signals, or
|
|
* take the next step if no child processes need to be killed.
|
|
*/
|
|
PostmasterStateMachine();
|
|
break;
|
|
|
|
case ImmediateShutdown:
|
|
|
|
/*
|
|
* Immediate Shutdown:
|
|
*
|
|
* abort all children with SIGQUIT, wait for them to exit,
|
|
* terminate remaining ones with SIGKILL, then exit without
|
|
* attempt to properly shut down the data base system.
|
|
*/
|
|
if (Shutdown >= ImmediateShutdown)
|
|
break;
|
|
Shutdown = ImmediateShutdown;
|
|
ereport(LOG,
|
|
(errmsg("received immediate shutdown request")));
|
|
|
|
/* Report status */
|
|
AddToDataDirLockFile(LOCK_FILE_LINE_PM_STATUS, PM_STATUS_STOPPING);
|
|
#ifdef USE_SYSTEMD
|
|
sd_notify(0, "STOPPING=1");
|
|
#endif
|
|
|
|
/* tell children to shut down ASAP */
|
|
/* (note we don't apply send_abort_for_crash here) */
|
|
SetQuitSignalReason(PMQUIT_FOR_STOP);
|
|
TerminateChildren(SIGQUIT);
|
|
pmState = PM_WAIT_BACKENDS;
|
|
|
|
/* set stopwatch for them to die */
|
|
AbortStartTime = time(NULL);
|
|
|
|
/*
|
|
* Now wait for backends to exit. If there are none,
|
|
* PostmasterStateMachine will take the next step.
|
|
*/
|
|
PostmasterStateMachine();
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void
|
|
handle_pm_child_exit_signal(SIGNAL_ARGS)
|
|
{
|
|
pending_pm_child_exit = true;
|
|
SetLatch(MyLatch);
|
|
}
|
|
|
|
/*
|
|
* Cleanup after a child process dies.
|
|
*/
|
|
static void
|
|
process_pm_child_exit(void)
|
|
{
|
|
int pid; /* process id of dead child process */
|
|
int exitstatus; /* its exit status */
|
|
|
|
pending_pm_child_exit = false;
|
|
|
|
ereport(DEBUG4,
|
|
(errmsg_internal("reaping dead processes")));
|
|
|
|
while ((pid = waitpid(-1, &exitstatus, WNOHANG)) > 0)
|
|
{
|
|
/*
|
|
* Check if this child was a startup process.
|
|
*/
|
|
if (pid == StartupPID)
|
|
{
|
|
StartupPID = 0;
|
|
|
|
/*
|
|
* Startup process exited in response to a shutdown request (or it
|
|
* completed normally regardless of the shutdown request).
|
|
*/
|
|
if (Shutdown > NoShutdown &&
|
|
(EXIT_STATUS_0(exitstatus) || EXIT_STATUS_1(exitstatus)))
|
|
{
|
|
StartupStatus = STARTUP_NOT_RUNNING;
|
|
pmState = PM_WAIT_BACKENDS;
|
|
/* PostmasterStateMachine logic does the rest */
|
|
continue;
|
|
}
|
|
|
|
if (EXIT_STATUS_3(exitstatus))
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("shutdown at recovery target")));
|
|
StartupStatus = STARTUP_NOT_RUNNING;
|
|
Shutdown = Max(Shutdown, SmartShutdown);
|
|
TerminateChildren(SIGTERM);
|
|
pmState = PM_WAIT_BACKENDS;
|
|
/* PostmasterStateMachine logic does the rest */
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Unexpected exit of startup process (including FATAL exit)
|
|
* during PM_STARTUP is treated as catastrophic. There are no
|
|
* other processes running yet, so we can just exit.
|
|
*/
|
|
if (pmState == PM_STARTUP &&
|
|
StartupStatus != STARTUP_SIGNALED &&
|
|
!EXIT_STATUS_0(exitstatus))
|
|
{
|
|
LogChildExit(LOG, _("startup process"),
|
|
pid, exitstatus);
|
|
ereport(LOG,
|
|
(errmsg("aborting startup due to startup process failure")));
|
|
ExitPostmaster(1);
|
|
}
|
|
|
|
/*
|
|
* After PM_STARTUP, any unexpected exit (including FATAL exit) of
|
|
* the startup process is catastrophic, so kill other children,
|
|
* and set StartupStatus so we don't try to reinitialize after
|
|
* they're gone. Exception: if StartupStatus is STARTUP_SIGNALED,
|
|
* then we previously sent the startup process a SIGQUIT; so
|
|
* that's probably the reason it died, and we do want to try to
|
|
* restart in that case.
|
|
*
|
|
* This stanza also handles the case where we sent a SIGQUIT
|
|
* during PM_STARTUP due to some dead_end child crashing: in that
|
|
* situation, if the startup process dies on the SIGQUIT, we need
|
|
* to transition to PM_WAIT_BACKENDS state which will allow
|
|
* PostmasterStateMachine to restart the startup process. (On the
|
|
* other hand, the startup process might complete normally, if we
|
|
* were too late with the SIGQUIT. In that case we'll fall
|
|
* through and commence normal operations.)
|
|
*/
|
|
if (!EXIT_STATUS_0(exitstatus))
|
|
{
|
|
if (StartupStatus == STARTUP_SIGNALED)
|
|
{
|
|
StartupStatus = STARTUP_NOT_RUNNING;
|
|
if (pmState == PM_STARTUP)
|
|
pmState = PM_WAIT_BACKENDS;
|
|
}
|
|
else
|
|
StartupStatus = STARTUP_CRASHED;
|
|
HandleChildCrash(pid, exitstatus,
|
|
_("startup process"));
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Startup succeeded, commence normal operations
|
|
*/
|
|
StartupStatus = STARTUP_NOT_RUNNING;
|
|
FatalError = false;
|
|
AbortStartTime = 0;
|
|
ReachedNormalRunning = true;
|
|
pmState = PM_RUN;
|
|
connsAllowed = true;
|
|
|
|
/*
|
|
* Crank up the background tasks, if we didn't do that already
|
|
* when we entered consistent recovery state. It doesn't matter
|
|
* if this fails, we'll just try again later.
|
|
*/
|
|
if (CheckpointerPID == 0)
|
|
CheckpointerPID = StartChildProcess(B_CHECKPOINTER);
|
|
if (BgWriterPID == 0)
|
|
BgWriterPID = StartChildProcess(B_BG_WRITER);
|
|
if (WalWriterPID == 0)
|
|
WalWriterPID = StartChildProcess(B_WAL_WRITER);
|
|
MaybeStartWalSummarizer();
|
|
|
|
/*
|
|
* Likewise, start other special children as needed. In a restart
|
|
* situation, some of them may be alive already.
|
|
*/
|
|
if (!IsBinaryUpgrade && AutoVacuumingActive() && AutoVacPID == 0)
|
|
AutoVacPID = StartChildProcess(B_AUTOVAC_LAUNCHER);
|
|
if (PgArchStartupAllowed() && PgArchPID == 0)
|
|
PgArchPID = StartChildProcess(B_ARCHIVER);
|
|
MaybeStartSlotSyncWorker();
|
|
|
|
/* workers may be scheduled to start now */
|
|
maybe_start_bgworkers();
|
|
|
|
/* at this point we are really open for business */
|
|
ereport(LOG,
|
|
(errmsg("database system is ready to accept connections")));
|
|
|
|
/* Report status */
|
|
AddToDataDirLockFile(LOCK_FILE_LINE_PM_STATUS, PM_STATUS_READY);
|
|
#ifdef USE_SYSTEMD
|
|
sd_notify(0, "READY=1");
|
|
#endif
|
|
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Was it the bgwriter? Normal exit can be ignored; we'll start a new
|
|
* one at the next iteration of the postmaster's main loop, if
|
|
* necessary. Any other exit condition is treated as a crash.
|
|
*/
|
|
if (pid == BgWriterPID)
|
|
{
|
|
BgWriterPID = 0;
|
|
if (!EXIT_STATUS_0(exitstatus))
|
|
HandleChildCrash(pid, exitstatus,
|
|
_("background writer process"));
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Was it the checkpointer?
|
|
*/
|
|
if (pid == CheckpointerPID)
|
|
{
|
|
CheckpointerPID = 0;
|
|
if (EXIT_STATUS_0(exitstatus) && pmState == PM_SHUTDOWN)
|
|
{
|
|
/*
|
|
* OK, we saw normal exit of the checkpointer after it's been
|
|
* told to shut down. We expect that it wrote a shutdown
|
|
* checkpoint. (If for some reason it didn't, recovery will
|
|
* occur on next postmaster start.)
|
|
*
|
|
* At this point we should have no normal backend children
|
|
* left (else we'd not be in PM_SHUTDOWN state) but we might
|
|
* have dead_end children to wait for.
|
|
*
|
|
* If we have an archiver subprocess, tell it to do a last
|
|
* archive cycle and quit. Likewise, if we have walsender
|
|
* processes, tell them to send any remaining WAL and quit.
|
|
*/
|
|
Assert(Shutdown > NoShutdown);
|
|
|
|
/* Waken archiver for the last time */
|
|
if (PgArchPID != 0)
|
|
signal_child(PgArchPID, SIGUSR2);
|
|
|
|
/*
|
|
* Waken walsenders for the last time. No regular backends
|
|
* should be around anymore.
|
|
*/
|
|
SignalChildren(SIGUSR2);
|
|
|
|
pmState = PM_SHUTDOWN_2;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Any unexpected exit of the checkpointer (including FATAL
|
|
* exit) is treated as a crash.
|
|
*/
|
|
HandleChildCrash(pid, exitstatus,
|
|
_("checkpointer process"));
|
|
}
|
|
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Was it the wal writer? Normal exit can be ignored; we'll start a
|
|
* new one at the next iteration of the postmaster's main loop, if
|
|
* necessary. Any other exit condition is treated as a crash.
|
|
*/
|
|
if (pid == WalWriterPID)
|
|
{
|
|
WalWriterPID = 0;
|
|
if (!EXIT_STATUS_0(exitstatus))
|
|
HandleChildCrash(pid, exitstatus,
|
|
_("WAL writer process"));
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Was it the wal receiver? If exit status is zero (normal) or one
|
|
* (FATAL exit), we assume everything is all right just like normal
|
|
* backends. (If we need a new wal receiver, we'll start one at the
|
|
* next iteration of the postmaster's main loop.)
|
|
*/
|
|
if (pid == WalReceiverPID)
|
|
{
|
|
WalReceiverPID = 0;
|
|
if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
|
|
HandleChildCrash(pid, exitstatus,
|
|
_("WAL receiver process"));
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Was it the wal summarizer? Normal exit can be ignored; we'll start
|
|
* a new one at the next iteration of the postmaster's main loop, if
|
|
* necessary. Any other exit condition is treated as a crash.
|
|
*/
|
|
if (pid == WalSummarizerPID)
|
|
{
|
|
WalSummarizerPID = 0;
|
|
if (!EXIT_STATUS_0(exitstatus))
|
|
HandleChildCrash(pid, exitstatus,
|
|
_("WAL summarizer process"));
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Was it the autovacuum launcher? Normal exit can be ignored; we'll
|
|
* start a new one at the next iteration of the postmaster's main
|
|
* loop, if necessary. Any other exit condition is treated as a
|
|
* crash.
|
|
*/
|
|
if (pid == AutoVacPID)
|
|
{
|
|
AutoVacPID = 0;
|
|
if (!EXIT_STATUS_0(exitstatus))
|
|
HandleChildCrash(pid, exitstatus,
|
|
_("autovacuum launcher process"));
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Was it the archiver? If exit status is zero (normal) or one (FATAL
|
|
* exit), we assume everything is all right just like normal backends
|
|
* and just try to restart a new one so that we immediately retry
|
|
* archiving remaining files. (If fail, we'll try again in future
|
|
* cycles of the postmaster's main loop.) Unless we were waiting for
|
|
* it to shut down; don't restart it in that case, and
|
|
* PostmasterStateMachine() will advance to the next shutdown step.
|
|
*/
|
|
if (pid == PgArchPID)
|
|
{
|
|
PgArchPID = 0;
|
|
if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
|
|
HandleChildCrash(pid, exitstatus,
|
|
_("archiver process"));
|
|
if (PgArchStartupAllowed())
|
|
PgArchPID = StartChildProcess(B_ARCHIVER);
|
|
continue;
|
|
}
|
|
|
|
/* Was it the system logger? If so, try to start a new one */
|
|
if (pid == SysLoggerPID)
|
|
{
|
|
SysLoggerPID = 0;
|
|
/* for safety's sake, launch new logger *first* */
|
|
SysLoggerPID = SysLogger_Start();
|
|
if (!EXIT_STATUS_0(exitstatus))
|
|
LogChildExit(LOG, _("system logger process"),
|
|
pid, exitstatus);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Was it the slot sync worker? Normal exit or FATAL exit can be
|
|
* ignored (FATAL can be caused by libpqwalreceiver on receiving
|
|
* shutdown request by the startup process during promotion); we'll
|
|
* start a new one at the next iteration of the postmaster's main
|
|
* loop, if necessary. Any other exit condition is treated as a crash.
|
|
*/
|
|
if (pid == SlotSyncWorkerPID)
|
|
{
|
|
SlotSyncWorkerPID = 0;
|
|
if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
|
|
HandleChildCrash(pid, exitstatus,
|
|
_("slot sync worker process"));
|
|
continue;
|
|
}
|
|
|
|
/* Was it one of our background workers? */
|
|
if (CleanupBackgroundWorker(pid, exitstatus))
|
|
{
|
|
/* have it be restarted */
|
|
HaveCrashedWorker = true;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Else do standard backend child cleanup.
|
|
*/
|
|
CleanupBackend(pid, exitstatus);
|
|
} /* loop over pending child-death reports */
|
|
|
|
/*
|
|
* After cleaning out the SIGCHLD queue, see if we have any state changes
|
|
* or actions to make.
|
|
*/
|
|
PostmasterStateMachine();
|
|
}
|
|
|
|
/*
|
|
* Scan the bgworkers list and see if the given PID (which has just stopped
|
|
* or crashed) is in it. Handle its shutdown if so, and return true. If not a
|
|
* bgworker, return false.
|
|
*
|
|
* This is heavily based on CleanupBackend. One important difference is that
|
|
* we don't know yet that the dying process is a bgworker, so we must be silent
|
|
* until we're sure it is.
|
|
*/
|
|
static bool
|
|
CleanupBackgroundWorker(int pid,
|
|
int exitstatus) /* child's exit status */
|
|
{
|
|
char namebuf[MAXPGPATH];
|
|
slist_mutable_iter iter;
|
|
|
|
slist_foreach_modify(iter, &BackgroundWorkerList)
|
|
{
|
|
RegisteredBgWorker *rw;
|
|
|
|
rw = slist_container(RegisteredBgWorker, rw_lnode, iter.cur);
|
|
|
|
if (rw->rw_pid != pid)
|
|
continue;
|
|
|
|
#ifdef WIN32
|
|
/* see CleanupBackend */
|
|
if (exitstatus == ERROR_WAIT_NO_CHILDREN)
|
|
exitstatus = 0;
|
|
#endif
|
|
|
|
snprintf(namebuf, MAXPGPATH, _("background worker \"%s\""),
|
|
rw->rw_worker.bgw_type);
|
|
|
|
|
|
if (!EXIT_STATUS_0(exitstatus))
|
|
{
|
|
/* Record timestamp, so we know when to restart the worker. */
|
|
rw->rw_crashed_at = GetCurrentTimestamp();
|
|
}
|
|
else
|
|
{
|
|
/* Zero exit status means terminate */
|
|
rw->rw_crashed_at = 0;
|
|
rw->rw_terminate = true;
|
|
}
|
|
|
|
/*
|
|
* Additionally, just like a backend, any exit status other than 0 or
|
|
* 1 is considered a crash and causes a system-wide restart.
|
|
*/
|
|
if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
|
|
{
|
|
HandleChildCrash(pid, exitstatus, namebuf);
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* We must release the postmaster child slot. If the worker failed to
|
|
* do so, it did not clean up after itself, requiring a crash-restart
|
|
* cycle.
|
|
*/
|
|
if (!ReleasePostmasterChildSlot(rw->rw_child_slot))
|
|
{
|
|
HandleChildCrash(pid, exitstatus, namebuf);
|
|
return true;
|
|
}
|
|
|
|
/* Get it out of the BackendList and clear out remaining data */
|
|
dlist_delete(&rw->rw_backend->elem);
|
|
#ifdef EXEC_BACKEND
|
|
ShmemBackendArrayRemove(rw->rw_backend);
|
|
#endif
|
|
|
|
/*
|
|
* It's possible that this background worker started some OTHER
|
|
* background worker and asked to be notified when that worker started
|
|
* or stopped. If so, cancel any notifications destined for the
|
|
* now-dead backend.
|
|
*/
|
|
if (rw->rw_backend->bgworker_notify)
|
|
BackgroundWorkerStopNotifications(rw->rw_pid);
|
|
pfree(rw->rw_backend);
|
|
rw->rw_backend = NULL;
|
|
rw->rw_pid = 0;
|
|
rw->rw_child_slot = 0;
|
|
ReportBackgroundWorkerExit(&iter); /* report child death */
|
|
|
|
LogChildExit(EXIT_STATUS_0(exitstatus) ? DEBUG1 : LOG,
|
|
namebuf, pid, exitstatus);
|
|
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* CleanupBackend -- cleanup after terminated backend.
|
|
*
|
|
* Remove all local state associated with backend.
|
|
*
|
|
* If you change this, see also CleanupBackgroundWorker.
|
|
*/
|
|
static void
|
|
CleanupBackend(int pid,
|
|
int exitstatus) /* child's exit status. */
|
|
{
|
|
dlist_mutable_iter iter;
|
|
|
|
LogChildExit(DEBUG2, _("server process"), pid, exitstatus);
|
|
|
|
/*
|
|
* If a backend dies in an ugly way then we must signal all other backends
|
|
* to quickdie. If exit status is zero (normal) or one (FATAL exit), we
|
|
* assume everything is all right and proceed to remove the backend from
|
|
* the active backend list.
|
|
*/
|
|
|
|
#ifdef WIN32
|
|
|
|
/*
|
|
* On win32, also treat ERROR_WAIT_NO_CHILDREN (128) as nonfatal case,
|
|
* since that sometimes happens under load when the process fails to start
|
|
* properly (long before it starts using shared memory). Microsoft reports
|
|
* it is related to mutex failure:
|
|
* http://archives.postgresql.org/pgsql-hackers/2010-09/msg00790.php
|
|
*/
|
|
if (exitstatus == ERROR_WAIT_NO_CHILDREN)
|
|
{
|
|
LogChildExit(LOG, _("server process"), pid, exitstatus);
|
|
exitstatus = 0;
|
|
}
|
|
#endif
|
|
|
|
if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
|
|
{
|
|
HandleChildCrash(pid, exitstatus, _("server process"));
|
|
return;
|
|
}
|
|
|
|
dlist_foreach_modify(iter, &BackendList)
|
|
{
|
|
Backend *bp = dlist_container(Backend, elem, iter.cur);
|
|
|
|
if (bp->pid == pid)
|
|
{
|
|
if (!bp->dead_end)
|
|
{
|
|
if (!ReleasePostmasterChildSlot(bp->child_slot))
|
|
{
|
|
/*
|
|
* Uh-oh, the child failed to clean itself up. Treat as a
|
|
* crash after all.
|
|
*/
|
|
HandleChildCrash(pid, exitstatus, _("server process"));
|
|
return;
|
|
}
|
|
#ifdef EXEC_BACKEND
|
|
ShmemBackendArrayRemove(bp);
|
|
#endif
|
|
}
|
|
if (bp->bgworker_notify)
|
|
{
|
|
/*
|
|
* This backend may have been slated to receive SIGUSR1 when
|
|
* some background worker started or stopped. Cancel those
|
|
* notifications, as we don't want to signal PIDs that are not
|
|
* PostgreSQL backends. This gets skipped in the (probably
|
|
* very common) case where the backend has never requested any
|
|
* such notifications.
|
|
*/
|
|
BackgroundWorkerStopNotifications(bp->pid);
|
|
}
|
|
dlist_delete(iter.cur);
|
|
pfree(bp);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* HandleChildCrash -- cleanup after failed backend, bgwriter, checkpointer,
|
|
* walwriter, autovacuum, archiver, slot sync worker, or background worker.
|
|
*
|
|
* The objectives here are to clean up our local state about the child
|
|
* process, and to signal all other remaining children to quickdie.
|
|
*/
|
|
static void
|
|
HandleChildCrash(int pid, int exitstatus, const char *procname)
|
|
{
|
|
dlist_mutable_iter iter;
|
|
slist_iter siter;
|
|
Backend *bp;
|
|
bool take_action;
|
|
|
|
/*
|
|
* We only log messages and send signals if this is the first process
|
|
* crash and we're not doing an immediate shutdown; otherwise, we're only
|
|
* here to update postmaster's idea of live processes. If we have already
|
|
* signaled children, nonzero exit status is to be expected, so don't
|
|
* clutter log.
|
|
*/
|
|
take_action = !FatalError && Shutdown != ImmediateShutdown;
|
|
|
|
if (take_action)
|
|
{
|
|
LogChildExit(LOG, procname, pid, exitstatus);
|
|
ereport(LOG,
|
|
(errmsg("terminating any other active server processes")));
|
|
SetQuitSignalReason(PMQUIT_FOR_CRASH);
|
|
}
|
|
|
|
/* Process background workers. */
|
|
slist_foreach(siter, &BackgroundWorkerList)
|
|
{
|
|
RegisteredBgWorker *rw;
|
|
|
|
rw = slist_container(RegisteredBgWorker, rw_lnode, siter.cur);
|
|
if (rw->rw_pid == 0)
|
|
continue; /* not running */
|
|
if (rw->rw_pid == pid)
|
|
{
|
|
/*
|
|
* Found entry for freshly-dead worker, so remove it.
|
|
*/
|
|
(void) ReleasePostmasterChildSlot(rw->rw_child_slot);
|
|
dlist_delete(&rw->rw_backend->elem);
|
|
#ifdef EXEC_BACKEND
|
|
ShmemBackendArrayRemove(rw->rw_backend);
|
|
#endif
|
|
pfree(rw->rw_backend);
|
|
rw->rw_backend = NULL;
|
|
rw->rw_pid = 0;
|
|
rw->rw_child_slot = 0;
|
|
/* don't reset crashed_at */
|
|
/* don't report child stop, either */
|
|
/* Keep looping so we can signal remaining workers */
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* This worker is still alive. Unless we did so already, tell it
|
|
* to commit hara-kiri.
|
|
*/
|
|
if (take_action)
|
|
sigquit_child(rw->rw_pid);
|
|
}
|
|
}
|
|
|
|
/* Process regular backends */
|
|
dlist_foreach_modify(iter, &BackendList)
|
|
{
|
|
bp = dlist_container(Backend, elem, iter.cur);
|
|
|
|
if (bp->pid == pid)
|
|
{
|
|
/*
|
|
* Found entry for freshly-dead backend, so remove it.
|
|
*/
|
|
if (!bp->dead_end)
|
|
{
|
|
(void) ReleasePostmasterChildSlot(bp->child_slot);
|
|
#ifdef EXEC_BACKEND
|
|
ShmemBackendArrayRemove(bp);
|
|
#endif
|
|
}
|
|
dlist_delete(iter.cur);
|
|
pfree(bp);
|
|
/* Keep looping so we can signal remaining backends */
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* This backend is still alive. Unless we did so already, tell it
|
|
* to commit hara-kiri.
|
|
*
|
|
* We could exclude dead_end children here, but at least when
|
|
* sending SIGABRT it seems better to include them.
|
|
*
|
|
* Background workers were already processed above; ignore them
|
|
* here.
|
|
*/
|
|
if (bp->bkend_type == BACKEND_TYPE_BGWORKER)
|
|
continue;
|
|
|
|
if (take_action)
|
|
sigquit_child(bp->pid);
|
|
}
|
|
}
|
|
|
|
/* Take care of the startup process too */
|
|
if (pid == StartupPID)
|
|
{
|
|
StartupPID = 0;
|
|
/* Caller adjusts StartupStatus, so don't touch it here */
|
|
}
|
|
else if (StartupPID != 0 && take_action)
|
|
{
|
|
sigquit_child(StartupPID);
|
|
StartupStatus = STARTUP_SIGNALED;
|
|
}
|
|
|
|
/* Take care of the bgwriter too */
|
|
if (pid == BgWriterPID)
|
|
BgWriterPID = 0;
|
|
else if (BgWriterPID != 0 && take_action)
|
|
sigquit_child(BgWriterPID);
|
|
|
|
/* Take care of the checkpointer too */
|
|
if (pid == CheckpointerPID)
|
|
CheckpointerPID = 0;
|
|
else if (CheckpointerPID != 0 && take_action)
|
|
sigquit_child(CheckpointerPID);
|
|
|
|
/* Take care of the walwriter too */
|
|
if (pid == WalWriterPID)
|
|
WalWriterPID = 0;
|
|
else if (WalWriterPID != 0 && take_action)
|
|
sigquit_child(WalWriterPID);
|
|
|
|
/* Take care of the walreceiver too */
|
|
if (pid == WalReceiverPID)
|
|
WalReceiverPID = 0;
|
|
else if (WalReceiverPID != 0 && take_action)
|
|
sigquit_child(WalReceiverPID);
|
|
|
|
/* Take care of the walsummarizer too */
|
|
if (pid == WalSummarizerPID)
|
|
WalSummarizerPID = 0;
|
|
else if (WalSummarizerPID != 0 && take_action)
|
|
sigquit_child(WalSummarizerPID);
|
|
|
|
/* Take care of the autovacuum launcher too */
|
|
if (pid == AutoVacPID)
|
|
AutoVacPID = 0;
|
|
else if (AutoVacPID != 0 && take_action)
|
|
sigquit_child(AutoVacPID);
|
|
|
|
/* Take care of the archiver too */
|
|
if (pid == PgArchPID)
|
|
PgArchPID = 0;
|
|
else if (PgArchPID != 0 && take_action)
|
|
sigquit_child(PgArchPID);
|
|
|
|
/* Take care of the slot sync worker too */
|
|
if (pid == SlotSyncWorkerPID)
|
|
SlotSyncWorkerPID = 0;
|
|
else if (SlotSyncWorkerPID != 0 && take_action)
|
|
sigquit_child(SlotSyncWorkerPID);
|
|
|
|
/* We do NOT restart the syslogger */
|
|
|
|
if (Shutdown != ImmediateShutdown)
|
|
FatalError = true;
|
|
|
|
/* We now transit into a state of waiting for children to die */
|
|
if (pmState == PM_RECOVERY ||
|
|
pmState == PM_HOT_STANDBY ||
|
|
pmState == PM_RUN ||
|
|
pmState == PM_STOP_BACKENDS ||
|
|
pmState == PM_SHUTDOWN)
|
|
pmState = PM_WAIT_BACKENDS;
|
|
|
|
/*
|
|
* .. and if this doesn't happen quickly enough, now the clock is ticking
|
|
* for us to kill them without mercy.
|
|
*/
|
|
if (AbortStartTime == 0)
|
|
AbortStartTime = time(NULL);
|
|
}
|
|
|
|
/*
|
|
* Log the death of a child process.
|
|
*/
|
|
static void
|
|
LogChildExit(int lev, const char *procname, int pid, int exitstatus)
|
|
{
|
|
/*
|
|
* size of activity_buffer is arbitrary, but set equal to default
|
|
* track_activity_query_size
|
|
*/
|
|
char activity_buffer[1024];
|
|
const char *activity = NULL;
|
|
|
|
if (!EXIT_STATUS_0(exitstatus))
|
|
activity = pgstat_get_crashed_backend_activity(pid,
|
|
activity_buffer,
|
|
sizeof(activity_buffer));
|
|
|
|
if (WIFEXITED(exitstatus))
|
|
ereport(lev,
|
|
|
|
/*------
|
|
translator: %s is a noun phrase describing a child process, such as
|
|
"server process" */
|
|
(errmsg("%s (PID %d) exited with exit code %d",
|
|
procname, pid, WEXITSTATUS(exitstatus)),
|
|
activity ? errdetail("Failed process was running: %s", activity) : 0));
|
|
else if (WIFSIGNALED(exitstatus))
|
|
{
|
|
#if defined(WIN32)
|
|
ereport(lev,
|
|
|
|
/*------
|
|
translator: %s is a noun phrase describing a child process, such as
|
|
"server process" */
|
|
(errmsg("%s (PID %d) was terminated by exception 0x%X",
|
|
procname, pid, WTERMSIG(exitstatus)),
|
|
errhint("See C include file \"ntstatus.h\" for a description of the hexadecimal value."),
|
|
activity ? errdetail("Failed process was running: %s", activity) : 0));
|
|
#else
|
|
ereport(lev,
|
|
|
|
/*------
|
|
translator: %s is a noun phrase describing a child process, such as
|
|
"server process" */
|
|
(errmsg("%s (PID %d) was terminated by signal %d: %s",
|
|
procname, pid, WTERMSIG(exitstatus),
|
|
pg_strsignal(WTERMSIG(exitstatus))),
|
|
activity ? errdetail("Failed process was running: %s", activity) : 0));
|
|
#endif
|
|
}
|
|
else
|
|
ereport(lev,
|
|
|
|
/*------
|
|
translator: %s is a noun phrase describing a child process, such as
|
|
"server process" */
|
|
(errmsg("%s (PID %d) exited with unrecognized status %d",
|
|
procname, pid, exitstatus),
|
|
activity ? errdetail("Failed process was running: %s", activity) : 0));
|
|
}
|
|
|
|
/*
|
|
* Advance the postmaster's state machine and take actions as appropriate
|
|
*
|
|
* This is common code for process_pm_shutdown_request(),
|
|
* process_pm_child_exit() and process_pm_pmsignal(), which process the signals
|
|
* that might mean we need to change state.
|
|
*/
|
|
static void
|
|
PostmasterStateMachine(void)
|
|
{
|
|
/* If we're doing a smart shutdown, try to advance that state. */
|
|
if (pmState == PM_RUN || pmState == PM_HOT_STANDBY)
|
|
{
|
|
if (!connsAllowed)
|
|
{
|
|
/*
|
|
* This state ends when we have no normal client backends running.
|
|
* Then we're ready to stop other children.
|
|
*/
|
|
if (CountChildren(BACKEND_TYPE_NORMAL) == 0)
|
|
pmState = PM_STOP_BACKENDS;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we're ready to do so, signal child processes to shut down. (This
|
|
* isn't a persistent state, but treating it as a distinct pmState allows
|
|
* us to share this code across multiple shutdown code paths.)
|
|
*/
|
|
if (pmState == PM_STOP_BACKENDS)
|
|
{
|
|
/*
|
|
* Forget any pending requests for background workers, since we're no
|
|
* longer willing to launch any new workers. (If additional requests
|
|
* arrive, BackgroundWorkerStateChange will reject them.)
|
|
*/
|
|
ForgetUnstartedBackgroundWorkers();
|
|
|
|
/* Signal all backend children except walsenders */
|
|
SignalSomeChildren(SIGTERM,
|
|
BACKEND_TYPE_ALL - BACKEND_TYPE_WALSND);
|
|
/* and the autovac launcher too */
|
|
if (AutoVacPID != 0)
|
|
signal_child(AutoVacPID, SIGTERM);
|
|
/* and the bgwriter too */
|
|
if (BgWriterPID != 0)
|
|
signal_child(BgWriterPID, SIGTERM);
|
|
/* and the walwriter too */
|
|
if (WalWriterPID != 0)
|
|
signal_child(WalWriterPID, SIGTERM);
|
|
/* If we're in recovery, also stop startup and walreceiver procs */
|
|
if (StartupPID != 0)
|
|
signal_child(StartupPID, SIGTERM);
|
|
if (WalReceiverPID != 0)
|
|
signal_child(WalReceiverPID, SIGTERM);
|
|
if (WalSummarizerPID != 0)
|
|
signal_child(WalSummarizerPID, SIGTERM);
|
|
if (SlotSyncWorkerPID != 0)
|
|
signal_child(SlotSyncWorkerPID, SIGTERM);
|
|
/* checkpointer, archiver, stats, and syslogger may continue for now */
|
|
|
|
/* Now transition to PM_WAIT_BACKENDS state to wait for them to die */
|
|
pmState = PM_WAIT_BACKENDS;
|
|
}
|
|
|
|
/*
|
|
* If we are in a state-machine state that implies waiting for backends to
|
|
* exit, see if they're all gone, and change state if so.
|
|
*/
|
|
if (pmState == PM_WAIT_BACKENDS)
|
|
{
|
|
/*
|
|
* PM_WAIT_BACKENDS state ends when we have no regular backends
|
|
* (including autovac workers), no bgworkers (including unconnected
|
|
* ones), and no walwriter, autovac launcher, bgwriter or slot sync
|
|
* worker. If we are doing crash recovery or an immediate shutdown
|
|
* then we expect the checkpointer to exit as well, otherwise not. The
|
|
* stats and syslogger processes are disregarded since they are not
|
|
* connected to shared memory; we also disregard dead_end children
|
|
* here. Walsenders and archiver are also disregarded, they will be
|
|
* terminated later after writing the checkpoint record.
|
|
*/
|
|
if (CountChildren(BACKEND_TYPE_ALL - BACKEND_TYPE_WALSND) == 0 &&
|
|
StartupPID == 0 &&
|
|
WalReceiverPID == 0 &&
|
|
WalSummarizerPID == 0 &&
|
|
BgWriterPID == 0 &&
|
|
(CheckpointerPID == 0 ||
|
|
(!FatalError && Shutdown < ImmediateShutdown)) &&
|
|
WalWriterPID == 0 &&
|
|
AutoVacPID == 0 &&
|
|
SlotSyncWorkerPID == 0)
|
|
{
|
|
if (Shutdown >= ImmediateShutdown || FatalError)
|
|
{
|
|
/*
|
|
* Start waiting for dead_end children to die. This state
|
|
* change causes ServerLoop to stop creating new ones.
|
|
*/
|
|
pmState = PM_WAIT_DEAD_END;
|
|
|
|
/*
|
|
* We already SIGQUIT'd the archiver and stats processes, if
|
|
* any, when we started immediate shutdown or entered
|
|
* FatalError state.
|
|
*/
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* If we get here, we are proceeding with normal shutdown. All
|
|
* the regular children are gone, and it's time to tell the
|
|
* checkpointer to do a shutdown checkpoint.
|
|
*/
|
|
Assert(Shutdown > NoShutdown);
|
|
/* Start the checkpointer if not running */
|
|
if (CheckpointerPID == 0)
|
|
CheckpointerPID = StartChildProcess(B_CHECKPOINTER);
|
|
/* And tell it to shut down */
|
|
if (CheckpointerPID != 0)
|
|
{
|
|
signal_child(CheckpointerPID, SIGUSR2);
|
|
pmState = PM_SHUTDOWN;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* If we failed to fork a checkpointer, just shut down.
|
|
* Any required cleanup will happen at next restart. We
|
|
* set FatalError so that an "abnormal shutdown" message
|
|
* gets logged when we exit.
|
|
*
|
|
* We don't consult send_abort_for_crash here, as it's
|
|
* unlikely that dumping cores would illuminate the reason
|
|
* for checkpointer fork failure.
|
|
*/
|
|
FatalError = true;
|
|
pmState = PM_WAIT_DEAD_END;
|
|
|
|
/* Kill the walsenders and archiver too */
|
|
SignalChildren(SIGQUIT);
|
|
if (PgArchPID != 0)
|
|
signal_child(PgArchPID, SIGQUIT);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (pmState == PM_SHUTDOWN_2)
|
|
{
|
|
/*
|
|
* PM_SHUTDOWN_2 state ends when there's no other children than
|
|
* dead_end children left. There shouldn't be any regular backends
|
|
* left by now anyway; what we're really waiting for is walsenders and
|
|
* archiver.
|
|
*/
|
|
if (PgArchPID == 0 && CountChildren(BACKEND_TYPE_ALL) == 0)
|
|
{
|
|
pmState = PM_WAIT_DEAD_END;
|
|
}
|
|
}
|
|
|
|
if (pmState == PM_WAIT_DEAD_END)
|
|
{
|
|
/* Don't allow any new socket connection events. */
|
|
ConfigurePostmasterWaitSet(false);
|
|
|
|
/*
|
|
* PM_WAIT_DEAD_END state ends when the BackendList is entirely empty
|
|
* (ie, no dead_end children remain), and the archiver is gone too.
|
|
*
|
|
* The reason we wait for those two is to protect them against a new
|
|
* postmaster starting conflicting subprocesses; this isn't an
|
|
* ironclad protection, but it at least helps in the
|
|
* shutdown-and-immediately-restart scenario. Note that they have
|
|
* already been sent appropriate shutdown signals, either during a
|
|
* normal state transition leading up to PM_WAIT_DEAD_END, or during
|
|
* FatalError processing.
|
|
*/
|
|
if (dlist_is_empty(&BackendList) && PgArchPID == 0)
|
|
{
|
|
/* These other guys should be dead already */
|
|
Assert(StartupPID == 0);
|
|
Assert(WalReceiverPID == 0);
|
|
Assert(WalSummarizerPID == 0);
|
|
Assert(BgWriterPID == 0);
|
|
Assert(CheckpointerPID == 0);
|
|
Assert(WalWriterPID == 0);
|
|
Assert(AutoVacPID == 0);
|
|
Assert(SlotSyncWorkerPID == 0);
|
|
/* syslogger is not considered here */
|
|
pmState = PM_NO_CHILDREN;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we've been told to shut down, we exit as soon as there are no
|
|
* remaining children. If there was a crash, cleanup will occur at the
|
|
* next startup. (Before PostgreSQL 8.3, we tried to recover from the
|
|
* crash before exiting, but that seems unwise if we are quitting because
|
|
* we got SIGTERM from init --- there may well not be time for recovery
|
|
* before init decides to SIGKILL us.)
|
|
*
|
|
* Note that the syslogger continues to run. It will exit when it sees
|
|
* EOF on its input pipe, which happens when there are no more upstream
|
|
* processes.
|
|
*/
|
|
if (Shutdown > NoShutdown && pmState == PM_NO_CHILDREN)
|
|
{
|
|
if (FatalError)
|
|
{
|
|
ereport(LOG, (errmsg("abnormal database system shutdown")));
|
|
ExitPostmaster(1);
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Normal exit from the postmaster is here. We don't need to log
|
|
* anything here, since the UnlinkLockFiles proc_exit callback
|
|
* will do so, and that should be the last user-visible action.
|
|
*/
|
|
ExitPostmaster(0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If the startup process failed, or the user does not want an automatic
|
|
* restart after backend crashes, wait for all non-syslogger children to
|
|
* exit, and then exit postmaster. We don't try to reinitialize when the
|
|
* startup process fails, because more than likely it will just fail again
|
|
* and we will keep trying forever.
|
|
*/
|
|
if (pmState == PM_NO_CHILDREN)
|
|
{
|
|
if (StartupStatus == STARTUP_CRASHED)
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("shutting down due to startup process failure")));
|
|
ExitPostmaster(1);
|
|
}
|
|
if (!restart_after_crash)
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("shutting down because restart_after_crash is off")));
|
|
ExitPostmaster(1);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we need to recover from a crash, wait for all non-syslogger children
|
|
* to exit, then reset shmem and start the startup process.
|
|
*/
|
|
if (FatalError && pmState == PM_NO_CHILDREN)
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("all server processes terminated; reinitializing")));
|
|
|
|
/* remove leftover temporary files after a crash */
|
|
if (remove_temp_files_after_crash)
|
|
RemovePgTempFiles();
|
|
|
|
/* allow background workers to immediately restart */
|
|
ResetBackgroundWorkerCrashTimes();
|
|
|
|
shmem_exit(1);
|
|
|
|
/* re-read control file into local memory */
|
|
LocalProcessControlFile(true);
|
|
|
|
/* re-create shared memory and semaphores */
|
|
CreateSharedMemoryAndSemaphores();
|
|
|
|
StartupPID = StartChildProcess(B_STARTUP);
|
|
Assert(StartupPID != 0);
|
|
StartupStatus = STARTUP_RUNNING;
|
|
pmState = PM_STARTUP;
|
|
/* crash recovery started, reset SIGKILL flag */
|
|
AbortStartTime = 0;
|
|
|
|
/* start accepting server socket connection events again */
|
|
ConfigurePostmasterWaitSet(true);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Send a signal to a postmaster child process
|
|
*
|
|
* On systems that have setsid(), each child process sets itself up as a
|
|
* process group leader. For signals that are generally interpreted in the
|
|
* appropriate fashion, we signal the entire process group not just the
|
|
* direct child process. This allows us to, for example, SIGQUIT a blocked
|
|
* archive_recovery script, or SIGINT a script being run by a backend via
|
|
* system().
|
|
*
|
|
* There is a race condition for recently-forked children: they might not
|
|
* have executed setsid() yet. So we signal the child directly as well as
|
|
* the group. We assume such a child will handle the signal before trying
|
|
* to spawn any grandchild processes. We also assume that signaling the
|
|
* child twice will not cause any problems.
|
|
*/
|
|
static void
|
|
signal_child(pid_t pid, int signal)
|
|
{
|
|
if (kill(pid, signal) < 0)
|
|
elog(DEBUG3, "kill(%ld,%d) failed: %m", (long) pid, signal);
|
|
#ifdef HAVE_SETSID
|
|
switch (signal)
|
|
{
|
|
case SIGINT:
|
|
case SIGTERM:
|
|
case SIGQUIT:
|
|
case SIGKILL:
|
|
case SIGABRT:
|
|
if (kill(-pid, signal) < 0)
|
|
elog(DEBUG3, "kill(%ld,%d) failed: %m", (long) (-pid), signal);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Convenience function for killing a child process after a crash of some
|
|
* other child process. We log the action at a higher level than we would
|
|
* otherwise do, and we apply send_abort_for_crash to decide which signal
|
|
* to send. Normally it's SIGQUIT -- and most other comments in this file
|
|
* are written on the assumption that it is -- but developers might prefer
|
|
* to use SIGABRT to collect per-child core dumps.
|
|
*/
|
|
static void
|
|
sigquit_child(pid_t pid)
|
|
{
|
|
ereport(DEBUG2,
|
|
(errmsg_internal("sending %s to process %d",
|
|
(send_abort_for_crash ? "SIGABRT" : "SIGQUIT"),
|
|
(int) pid)));
|
|
signal_child(pid, (send_abort_for_crash ? SIGABRT : SIGQUIT));
|
|
}
|
|
|
|
/*
|
|
* Send a signal to the targeted children (but NOT special children;
|
|
* dead_end children are never signaled, either).
|
|
*/
|
|
static bool
|
|
SignalSomeChildren(int signal, int target)
|
|
{
|
|
dlist_iter iter;
|
|
bool signaled = false;
|
|
|
|
dlist_foreach(iter, &BackendList)
|
|
{
|
|
Backend *bp = dlist_container(Backend, elem, iter.cur);
|
|
|
|
if (bp->dead_end)
|
|
continue;
|
|
|
|
/*
|
|
* Since target == BACKEND_TYPE_ALL is the most common case, we test
|
|
* it first and avoid touching shared memory for every child.
|
|
*/
|
|
if (target != BACKEND_TYPE_ALL)
|
|
{
|
|
/*
|
|
* Assign bkend_type for any recently announced WAL Sender
|
|
* processes.
|
|
*/
|
|
if (bp->bkend_type == BACKEND_TYPE_NORMAL &&
|
|
IsPostmasterChildWalSender(bp->child_slot))
|
|
bp->bkend_type = BACKEND_TYPE_WALSND;
|
|
|
|
if (!(target & bp->bkend_type))
|
|
continue;
|
|
}
|
|
|
|
ereport(DEBUG4,
|
|
(errmsg_internal("sending signal %d to process %d",
|
|
signal, (int) bp->pid)));
|
|
signal_child(bp->pid, signal);
|
|
signaled = true;
|
|
}
|
|
return signaled;
|
|
}
|
|
|
|
/*
|
|
* Send a termination signal to children. This considers all of our children
|
|
* processes, except syslogger and dead_end backends.
|
|
*/
|
|
static void
|
|
TerminateChildren(int signal)
|
|
{
|
|
SignalChildren(signal);
|
|
if (StartupPID != 0)
|
|
{
|
|
signal_child(StartupPID, signal);
|
|
if (signal == SIGQUIT || signal == SIGKILL || signal == SIGABRT)
|
|
StartupStatus = STARTUP_SIGNALED;
|
|
}
|
|
if (BgWriterPID != 0)
|
|
signal_child(BgWriterPID, signal);
|
|
if (CheckpointerPID != 0)
|
|
signal_child(CheckpointerPID, signal);
|
|
if (WalWriterPID != 0)
|
|
signal_child(WalWriterPID, signal);
|
|
if (WalReceiverPID != 0)
|
|
signal_child(WalReceiverPID, signal);
|
|
if (WalSummarizerPID != 0)
|
|
signal_child(WalSummarizerPID, signal);
|
|
if (AutoVacPID != 0)
|
|
signal_child(AutoVacPID, signal);
|
|
if (PgArchPID != 0)
|
|
signal_child(PgArchPID, signal);
|
|
if (SlotSyncWorkerPID != 0)
|
|
signal_child(SlotSyncWorkerPID, signal);
|
|
}
|
|
|
|
/* Information passed from postmaster to backend process */
|
|
typedef struct BackendStartupData
|
|
{
|
|
CAC_state canAcceptConnections;
|
|
} BackendStartupData;
|
|
|
|
/*
|
|
* BackendStartup -- start backend process
|
|
*
|
|
* returns: STATUS_ERROR if the fork failed, STATUS_OK otherwise.
|
|
*
|
|
* Note: if you change this code, also consider StartAutovacuumWorker.
|
|
*/
|
|
static int
|
|
BackendStartup(ClientSocket *client_sock)
|
|
{
|
|
Backend *bn; /* for backend cleanup */
|
|
pid_t pid;
|
|
BackendStartupData startup_data;
|
|
|
|
/*
|
|
* Create backend data structure. Better before the fork() so we can
|
|
* handle failure cleanly.
|
|
*/
|
|
bn = (Backend *) palloc_extended(sizeof(Backend), MCXT_ALLOC_NO_OOM);
|
|
if (!bn)
|
|
{
|
|
ereport(LOG,
|
|
(errcode(ERRCODE_OUT_OF_MEMORY),
|
|
errmsg("out of memory")));
|
|
return STATUS_ERROR;
|
|
}
|
|
|
|
/*
|
|
* Compute the cancel key that will be assigned to this backend. The
|
|
* backend will have its own copy in the forked-off process' value of
|
|
* MyCancelKey, so that it can transmit the key to the frontend.
|
|
*/
|
|
if (!RandomCancelKey(&MyCancelKey))
|
|
{
|
|
pfree(bn);
|
|
ereport(LOG,
|
|
(errcode(ERRCODE_INTERNAL_ERROR),
|
|
errmsg("could not generate random cancel key")));
|
|
return STATUS_ERROR;
|
|
}
|
|
|
|
/* Pass down canAcceptConnections state */
|
|
startup_data.canAcceptConnections = canAcceptConnections(BACKEND_TYPE_NORMAL);
|
|
bn->dead_end = (startup_data.canAcceptConnections != CAC_OK);
|
|
bn->cancel_key = MyCancelKey;
|
|
|
|
/*
|
|
* Unless it's a dead_end child, assign it a child slot number
|
|
*/
|
|
if (!bn->dead_end)
|
|
bn->child_slot = MyPMChildSlot = AssignPostmasterChildSlot();
|
|
else
|
|
bn->child_slot = 0;
|
|
|
|
/* Hasn't asked to be notified about any bgworkers yet */
|
|
bn->bgworker_notify = false;
|
|
|
|
pid = postmaster_child_launch(B_BACKEND,
|
|
(char *) &startup_data, sizeof(startup_data),
|
|
client_sock);
|
|
if (pid < 0)
|
|
{
|
|
/* in parent, fork failed */
|
|
int save_errno = errno;
|
|
|
|
if (!bn->dead_end)
|
|
(void) ReleasePostmasterChildSlot(bn->child_slot);
|
|
pfree(bn);
|
|
errno = save_errno;
|
|
ereport(LOG,
|
|
(errmsg("could not fork new process for connection: %m")));
|
|
report_fork_failure_to_client(client_sock, save_errno);
|
|
return STATUS_ERROR;
|
|
}
|
|
|
|
/* in parent, successful fork */
|
|
ereport(DEBUG2,
|
|
(errmsg_internal("forked new backend, pid=%d socket=%d",
|
|
(int) pid, (int) client_sock->sock)));
|
|
|
|
/*
|
|
* Everything's been successful, it's safe to add this backend to our list
|
|
* of backends.
|
|
*/
|
|
bn->pid = pid;
|
|
bn->bkend_type = BACKEND_TYPE_NORMAL; /* Can change later to WALSND */
|
|
dlist_push_head(&BackendList, &bn->elem);
|
|
|
|
#ifdef EXEC_BACKEND
|
|
if (!bn->dead_end)
|
|
ShmemBackendArrayAdd(bn);
|
|
#endif
|
|
|
|
return STATUS_OK;
|
|
}
|
|
|
|
/*
|
|
* Try to report backend fork() failure to client before we close the
|
|
* connection. Since we do not care to risk blocking the postmaster on
|
|
* this connection, we set the connection to non-blocking and try only once.
|
|
*
|
|
* This is grungy special-purpose code; we cannot use backend libpq since
|
|
* it's not up and running.
|
|
*/
|
|
static void
|
|
report_fork_failure_to_client(ClientSocket *client_sock, int errnum)
|
|
{
|
|
char buffer[1000];
|
|
int rc;
|
|
|
|
/* Format the error message packet (always V2 protocol) */
|
|
snprintf(buffer, sizeof(buffer), "E%s%s\n",
|
|
_("could not fork new process for connection: "),
|
|
strerror(errnum));
|
|
|
|
/* Set port to non-blocking. Don't do send() if this fails */
|
|
if (!pg_set_noblock(client_sock->sock))
|
|
return;
|
|
|
|
/* We'll retry after EINTR, but ignore all other failures */
|
|
do
|
|
{
|
|
rc = send(client_sock->sock, buffer, strlen(buffer) + 1, 0);
|
|
} while (rc < 0 && errno == EINTR);
|
|
}
|
|
|
|
|
|
/*
|
|
* BackendInitialize -- initialize an interactive (postmaster-child)
|
|
* backend process, and collect the client's startup packet.
|
|
*
|
|
* returns: nothing. Will not return at all if there's any failure.
|
|
*
|
|
* Note: this code does not depend on having any access to shared memory.
|
|
* Indeed, our approach to SIGTERM/timeout handling *requires* that
|
|
* shared memory not have been touched yet; see comments within.
|
|
* In the EXEC_BACKEND case, we are physically attached to shared memory
|
|
* but have not yet set up most of our local pointers to shmem structures.
|
|
*/
|
|
static void
|
|
BackendInitialize(ClientSocket *client_sock, CAC_state cac)
|
|
{
|
|
int status;
|
|
int ret;
|
|
Port *port;
|
|
char remote_host[NI_MAXHOST];
|
|
char remote_port[NI_MAXSERV];
|
|
StringInfoData ps_data;
|
|
MemoryContext oldcontext;
|
|
|
|
/* Tell fd.c about the long-lived FD associated with the client_sock */
|
|
ReserveExternalFD();
|
|
|
|
/*
|
|
* PreAuthDelay is a debugging aid for investigating problems in the
|
|
* authentication cycle: it can be set in postgresql.conf to allow time to
|
|
* attach to the newly-forked backend with a debugger. (See also
|
|
* PostAuthDelay, which we allow clients to pass through PGOPTIONS, but it
|
|
* is not honored until after authentication.)
|
|
*/
|
|
if (PreAuthDelay > 0)
|
|
pg_usleep(PreAuthDelay * 1000000L);
|
|
|
|
/* This flag will remain set until InitPostgres finishes authentication */
|
|
ClientAuthInProgress = true; /* limit visibility of log messages */
|
|
|
|
/*
|
|
* Initialize libpq and enable reporting of ereport errors to the client.
|
|
* Must do this now because authentication uses libpq to send messages.
|
|
*
|
|
* The Port structure and all data structures attached to it are allocated
|
|
* in TopMemoryContext, so that they survive into PostgresMain execution.
|
|
* We need not worry about leaking this storage on failure, since we
|
|
* aren't in the postmaster process anymore.
|
|
*/
|
|
oldcontext = MemoryContextSwitchTo(TopMemoryContext);
|
|
port = MyProcPort = pq_init(client_sock);
|
|
MemoryContextSwitchTo(oldcontext);
|
|
|
|
whereToSendOutput = DestRemote; /* now safe to ereport to client */
|
|
|
|
/* set these to empty in case they are needed before we set them up */
|
|
port->remote_host = "";
|
|
port->remote_port = "";
|
|
|
|
/*
|
|
* We arrange to do _exit(1) if we receive SIGTERM or timeout while trying
|
|
* to collect the startup packet; while SIGQUIT results in _exit(2).
|
|
* Otherwise the postmaster cannot shutdown the database FAST or IMMED
|
|
* cleanly if a buggy client fails to send the packet promptly.
|
|
*
|
|
* Exiting with _exit(1) is only possible because we have not yet touched
|
|
* shared memory; therefore no outside-the-process state needs to get
|
|
* cleaned up.
|
|
*/
|
|
pqsignal(SIGTERM, process_startup_packet_die);
|
|
/* SIGQUIT handler was already set up by InitPostmasterChild */
|
|
InitializeTimeouts(); /* establishes SIGALRM handler */
|
|
sigprocmask(SIG_SETMASK, &StartupBlockSig, NULL);
|
|
|
|
/*
|
|
* Get the remote host name and port for logging and status display.
|
|
*/
|
|
remote_host[0] = '\0';
|
|
remote_port[0] = '\0';
|
|
if ((ret = pg_getnameinfo_all(&port->raddr.addr, port->raddr.salen,
|
|
remote_host, sizeof(remote_host),
|
|
remote_port, sizeof(remote_port),
|
|
(log_hostname ? 0 : NI_NUMERICHOST) | NI_NUMERICSERV)) != 0)
|
|
ereport(WARNING,
|
|
(errmsg_internal("pg_getnameinfo_all() failed: %s",
|
|
gai_strerror(ret))));
|
|
|
|
/*
|
|
* Save remote_host and remote_port in port structure (after this, they
|
|
* will appear in log_line_prefix data for log messages).
|
|
*/
|
|
oldcontext = MemoryContextSwitchTo(TopMemoryContext);
|
|
port->remote_host = pstrdup(remote_host);
|
|
port->remote_port = pstrdup(remote_port);
|
|
|
|
/* And now we can issue the Log_connections message, if wanted */
|
|
if (Log_connections)
|
|
{
|
|
if (remote_port[0])
|
|
ereport(LOG,
|
|
(errmsg("connection received: host=%s port=%s",
|
|
remote_host,
|
|
remote_port)));
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("connection received: host=%s",
|
|
remote_host)));
|
|
}
|
|
|
|
/*
|
|
* If we did a reverse lookup to name, we might as well save the results
|
|
* rather than possibly repeating the lookup during authentication.
|
|
*
|
|
* Note that we don't want to specify NI_NAMEREQD above, because then we'd
|
|
* get nothing useful for a client without an rDNS entry. Therefore, we
|
|
* must check whether we got a numeric IPv4 or IPv6 address, and not save
|
|
* it into remote_hostname if so. (This test is conservative and might
|
|
* sometimes classify a hostname as numeric, but an error in that
|
|
* direction is safe; it only results in a possible extra lookup.)
|
|
*/
|
|
if (log_hostname &&
|
|
ret == 0 &&
|
|
strspn(remote_host, "0123456789.") < strlen(remote_host) &&
|
|
strspn(remote_host, "0123456789ABCDEFabcdef:") < strlen(remote_host))
|
|
{
|
|
port->remote_hostname = pstrdup(remote_host);
|
|
}
|
|
MemoryContextSwitchTo(oldcontext);
|
|
|
|
/*
|
|
* Ready to begin client interaction. We will give up and _exit(1) after
|
|
* a time delay, so that a broken client can't hog a connection
|
|
* indefinitely. PreAuthDelay and any DNS interactions above don't count
|
|
* against the time limit.
|
|
*
|
|
* Note: AuthenticationTimeout is applied here while waiting for the
|
|
* startup packet, and then again in InitPostgres for the duration of any
|
|
* authentication operations. So a hostile client could tie up the
|
|
* process for nearly twice AuthenticationTimeout before we kick him off.
|
|
*
|
|
* Note: because PostgresMain will call InitializeTimeouts again, the
|
|
* registration of STARTUP_PACKET_TIMEOUT will be lost. This is okay
|
|
* since we never use it again after this function.
|
|
*/
|
|
RegisterTimeout(STARTUP_PACKET_TIMEOUT, StartupPacketTimeoutHandler);
|
|
enable_timeout_after(STARTUP_PACKET_TIMEOUT, AuthenticationTimeout * 1000);
|
|
|
|
/*
|
|
* Receive the startup packet (which might turn out to be a cancel request
|
|
* packet).
|
|
*/
|
|
status = ProcessStartupPacket(port, false, false);
|
|
|
|
/*
|
|
* If we're going to reject the connection due to database state, say so
|
|
* now instead of wasting cycles on an authentication exchange. (This also
|
|
* allows a pg_ping utility to be written.)
|
|
*/
|
|
if (status == STATUS_OK)
|
|
{
|
|
switch (cac)
|
|
{
|
|
case CAC_STARTUP:
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_CANNOT_CONNECT_NOW),
|
|
errmsg("the database system is starting up")));
|
|
break;
|
|
case CAC_NOTCONSISTENT:
|
|
if (EnableHotStandby)
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_CANNOT_CONNECT_NOW),
|
|
errmsg("the database system is not yet accepting connections"),
|
|
errdetail("Consistent recovery state has not been yet reached.")));
|
|
else
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_CANNOT_CONNECT_NOW),
|
|
errmsg("the database system is not accepting connections"),
|
|
errdetail("Hot standby mode is disabled.")));
|
|
break;
|
|
case CAC_SHUTDOWN:
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_CANNOT_CONNECT_NOW),
|
|
errmsg("the database system is shutting down")));
|
|
break;
|
|
case CAC_RECOVERY:
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_CANNOT_CONNECT_NOW),
|
|
errmsg("the database system is in recovery mode")));
|
|
break;
|
|
case CAC_TOOMANY:
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_TOO_MANY_CONNECTIONS),
|
|
errmsg("sorry, too many clients already")));
|
|
break;
|
|
case CAC_OK:
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Disable the timeout, and prevent SIGTERM again.
|
|
*/
|
|
disable_timeout(STARTUP_PACKET_TIMEOUT, false);
|
|
sigprocmask(SIG_SETMASK, &BlockSig, NULL);
|
|
|
|
/*
|
|
* As a safety check that nothing in startup has yet performed
|
|
* shared-memory modifications that would need to be undone if we had
|
|
* exited through SIGTERM or timeout above, check that no on_shmem_exit
|
|
* handlers have been registered yet. (This isn't terribly bulletproof,
|
|
* since someone might misuse an on_proc_exit handler for shmem cleanup,
|
|
* but it's a cheap and helpful check. We cannot disallow on_proc_exit
|
|
* handlers unfortunately, since pq_init() already registered one.)
|
|
*/
|
|
check_on_shmem_exit_lists_are_empty();
|
|
|
|
/*
|
|
* Stop here if it was bad or a cancel packet. ProcessStartupPacket
|
|
* already did any appropriate error reporting.
|
|
*/
|
|
if (status != STATUS_OK)
|
|
proc_exit(0);
|
|
|
|
/*
|
|
* Now that we have the user and database name, we can set the process
|
|
* title for ps. It's good to do this as early as possible in startup.
|
|
*/
|
|
initStringInfo(&ps_data);
|
|
if (am_walsender)
|
|
appendStringInfo(&ps_data, "%s ", GetBackendTypeDesc(B_WAL_SENDER));
|
|
appendStringInfo(&ps_data, "%s ", port->user_name);
|
|
if (port->database_name[0] != '\0')
|
|
appendStringInfo(&ps_data, "%s ", port->database_name);
|
|
appendStringInfoString(&ps_data, port->remote_host);
|
|
if (port->remote_port[0] != '\0')
|
|
appendStringInfo(&ps_data, "(%s)", port->remote_port);
|
|
|
|
init_ps_display(ps_data.data);
|
|
pfree(ps_data.data);
|
|
|
|
set_ps_display("initializing");
|
|
}
|
|
|
|
void
|
|
BackendMain(char *startup_data, size_t startup_data_len)
|
|
{
|
|
BackendStartupData *bsdata = (BackendStartupData *) startup_data;
|
|
|
|
Assert(startup_data_len == sizeof(BackendStartupData));
|
|
Assert(MyClientSocket != NULL);
|
|
|
|
#ifdef EXEC_BACKEND
|
|
|
|
/*
|
|
* Need to reinitialize the SSL library in the backend, since the context
|
|
* structures contain function pointers and cannot be passed through the
|
|
* parameter file.
|
|
*
|
|
* If for some reason reload fails (maybe the user installed broken key
|
|
* files), soldier on without SSL; that's better than all connections
|
|
* becoming impossible.
|
|
*
|
|
* XXX should we do this in all child processes? For the moment it's
|
|
* enough to do it in backend children.
|
|
*/
|
|
#ifdef USE_SSL
|
|
if (EnableSSL)
|
|
{
|
|
if (secure_initialize(false) == 0)
|
|
LoadedSSL = true;
|
|
else
|
|
ereport(LOG,
|
|
(errmsg("SSL configuration could not be loaded in child process")));
|
|
}
|
|
#endif
|
|
#endif
|
|
|
|
/* Perform additional initialization and collect startup packet */
|
|
BackendInitialize(MyClientSocket, bsdata->canAcceptConnections);
|
|
|
|
/*
|
|
* Create a per-backend PGPROC struct in shared memory. We must do this
|
|
* before we can use LWLocks or access any shared memory.
|
|
*/
|
|
InitProcess();
|
|
|
|
/*
|
|
* Make sure we aren't in PostmasterContext anymore. (We can't delete it
|
|
* just yet, though, because InitPostgres will need the HBA data.)
|
|
*/
|
|
MemoryContextSwitchTo(TopMemoryContext);
|
|
|
|
PostgresMain(MyProcPort->database_name, MyProcPort->user_name);
|
|
}
|
|
|
|
|
|
/*
|
|
* ExitPostmaster -- cleanup
|
|
*
|
|
* Do NOT call exit() directly --- always go through here!
|
|
*/
|
|
static void
|
|
ExitPostmaster(int status)
|
|
{
|
|
#ifdef HAVE_PTHREAD_IS_THREADED_NP
|
|
|
|
/*
|
|
* There is no known cause for a postmaster to become multithreaded after
|
|
* startup. Recheck to account for the possibility of unknown causes.
|
|
* This message uses LOG level, because an unclean shutdown at this point
|
|
* would usually not look much different from a clean shutdown.
|
|
*/
|
|
if (pthread_is_threaded_np() != 0)
|
|
ereport(LOG,
|
|
(errcode(ERRCODE_INTERNAL_ERROR),
|
|
errmsg_internal("postmaster became multithreaded"),
|
|
errdetail("Please report this to <%s>.", PACKAGE_BUGREPORT)));
|
|
#endif
|
|
|
|
/* should cleanup shared memory and kill all backends */
|
|
|
|
/*
|
|
* Not sure of the semantics here. When the Postmaster dies, should the
|
|
* backends all be killed? probably not.
|
|
*
|
|
* MUST -- vadim 05-10-1999
|
|
*/
|
|
|
|
proc_exit(status);
|
|
}
|
|
|
|
/*
|
|
* Handle pmsignal conditions representing requests from backends,
|
|
* and check for promote and logrotate requests from pg_ctl.
|
|
*/
|
|
static void
|
|
process_pm_pmsignal(void)
|
|
{
|
|
pending_pm_pmsignal = false;
|
|
|
|
ereport(DEBUG2,
|
|
(errmsg_internal("postmaster received pmsignal signal")));
|
|
|
|
/*
|
|
* RECOVERY_STARTED and BEGIN_HOT_STANDBY signals are ignored in
|
|
* unexpected states. If the startup process quickly starts up, completes
|
|
* recovery, exits, we might process the death of the startup process
|
|
* first. We don't want to go back to recovery in that case.
|
|
*/
|
|
if (CheckPostmasterSignal(PMSIGNAL_RECOVERY_STARTED) &&
|
|
pmState == PM_STARTUP && Shutdown == NoShutdown)
|
|
{
|
|
/* WAL redo has started. We're out of reinitialization. */
|
|
FatalError = false;
|
|
AbortStartTime = 0;
|
|
|
|
/*
|
|
* Start the archiver if we're responsible for (re-)archiving received
|
|
* files.
|
|
*/
|
|
Assert(PgArchPID == 0);
|
|
if (XLogArchivingAlways())
|
|
PgArchPID = StartChildProcess(B_ARCHIVER);
|
|
|
|
/*
|
|
* If we aren't planning to enter hot standby mode later, treat
|
|
* RECOVERY_STARTED as meaning we're out of startup, and report status
|
|
* accordingly.
|
|
*/
|
|
if (!EnableHotStandby)
|
|
{
|
|
AddToDataDirLockFile(LOCK_FILE_LINE_PM_STATUS, PM_STATUS_STANDBY);
|
|
#ifdef USE_SYSTEMD
|
|
sd_notify(0, "READY=1");
|
|
#endif
|
|
}
|
|
|
|
pmState = PM_RECOVERY;
|
|
}
|
|
|
|
if (CheckPostmasterSignal(PMSIGNAL_BEGIN_HOT_STANDBY) &&
|
|
pmState == PM_RECOVERY && Shutdown == NoShutdown)
|
|
{
|
|
ereport(LOG,
|
|
(errmsg("database system is ready to accept read-only connections")));
|
|
|
|
/* Report status */
|
|
AddToDataDirLockFile(LOCK_FILE_LINE_PM_STATUS, PM_STATUS_READY);
|
|
#ifdef USE_SYSTEMD
|
|
sd_notify(0, "READY=1");
|
|
#endif
|
|
|
|
pmState = PM_HOT_STANDBY;
|
|
connsAllowed = true;
|
|
|
|
/* Some workers may be scheduled to start now */
|
|
StartWorkerNeeded = true;
|
|
}
|
|
|
|
/* Process background worker state changes. */
|
|
if (CheckPostmasterSignal(PMSIGNAL_BACKGROUND_WORKER_CHANGE))
|
|
{
|
|
/* Accept new worker requests only if not stopping. */
|
|
BackgroundWorkerStateChange(pmState < PM_STOP_BACKENDS);
|
|
StartWorkerNeeded = true;
|
|
}
|
|
|
|
if (StartWorkerNeeded || HaveCrashedWorker)
|
|
maybe_start_bgworkers();
|
|
|
|
/* Tell syslogger to rotate logfile if requested */
|
|
if (SysLoggerPID != 0)
|
|
{
|
|
if (CheckLogrotateSignal())
|
|
{
|
|
signal_child(SysLoggerPID, SIGUSR1);
|
|
RemoveLogrotateSignalFiles();
|
|
}
|
|
else if (CheckPostmasterSignal(PMSIGNAL_ROTATE_LOGFILE))
|
|
{
|
|
signal_child(SysLoggerPID, SIGUSR1);
|
|
}
|
|
}
|
|
|
|
if (CheckPostmasterSignal(PMSIGNAL_START_AUTOVAC_LAUNCHER) &&
|
|
Shutdown <= SmartShutdown && pmState < PM_STOP_BACKENDS)
|
|
{
|
|
/*
|
|
* Start one iteration of the autovacuum daemon, even if autovacuuming
|
|
* is nominally not enabled. This is so we can have an active defense
|
|
* against transaction ID wraparound. We set a flag for the main loop
|
|
* to do it rather than trying to do it here --- this is because the
|
|
* autovac process itself may send the signal, and we want to handle
|
|
* that by launching another iteration as soon as the current one
|
|
* completes.
|
|
*/
|
|
start_autovac_launcher = true;
|
|
}
|
|
|
|
if (CheckPostmasterSignal(PMSIGNAL_START_AUTOVAC_WORKER) &&
|
|
Shutdown <= SmartShutdown && pmState < PM_STOP_BACKENDS)
|
|
{
|
|
/* The autovacuum launcher wants us to start a worker process. */
|
|
StartAutovacuumWorker();
|
|
}
|
|
|
|
if (CheckPostmasterSignal(PMSIGNAL_START_WALRECEIVER))
|
|
{
|
|
/* Startup Process wants us to start the walreceiver process. */
|
|
/* Start immediately if possible, else remember request for later. */
|
|
WalReceiverRequested = true;
|
|
MaybeStartWalReceiver();
|
|
}
|
|
|
|
/*
|
|
* Try to advance postmaster's state machine, if a child requests it.
|
|
*
|
|
* Be careful about the order of this action relative to this function's
|
|
* other actions. Generally, this should be after other actions, in case
|
|
* they have effects PostmasterStateMachine would need to know about.
|
|
* However, we should do it before the CheckPromoteSignal step, which
|
|
* cannot have any (immediate) effect on the state machine, but does
|
|
* depend on what state we're in now.
|
|
*/
|
|
if (CheckPostmasterSignal(PMSIGNAL_ADVANCE_STATE_MACHINE))
|
|
{
|
|
PostmasterStateMachine();
|
|
}
|
|
|
|
if (StartupPID != 0 &&
|
|
(pmState == PM_STARTUP || pmState == PM_RECOVERY ||
|
|
pmState == PM_HOT_STANDBY) &&
|
|
CheckPromoteSignal())
|
|
{
|
|
/*
|
|
* Tell startup process to finish recovery.
|
|
*
|
|
* Leave the promote signal file in place and let the Startup process
|
|
* do the unlink.
|
|
*/
|
|
signal_child(StartupPID, SIGUSR2);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* SIGTERM while processing startup packet.
|
|
*
|
|
* Running proc_exit() from a signal handler would be quite unsafe.
|
|
* However, since we have not yet touched shared memory, we can just
|
|
* pull the plug and exit without running any atexit handlers.
|
|
*
|
|
* One might be tempted to try to send a message, or log one, indicating
|
|
* why we are disconnecting. However, that would be quite unsafe in itself.
|
|
* Also, it seems undesirable to provide clues about the database's state
|
|
* to a client that has not yet completed authentication, or even sent us
|
|
* a startup packet.
|
|
*/
|
|
static void
|
|
process_startup_packet_die(SIGNAL_ARGS)
|
|
{
|
|
_exit(1);
|
|
}
|
|
|
|
/*
|
|
* Dummy signal handler
|
|
*
|
|
* We use this for signals that we don't actually use in the postmaster,
|
|
* but we do use in backends. If we were to SIG_IGN such signals in the
|
|
* postmaster, then a newly started backend might drop a signal that arrives
|
|
* before it's able to reconfigure its signal processing. (See notes in
|
|
* tcop/postgres.c.)
|
|
*/
|
|
static void
|
|
dummy_handler(SIGNAL_ARGS)
|
|
{
|
|
}
|
|
|
|
/*
|
|
* Timeout while processing startup packet.
|
|
* As for process_startup_packet_die(), we exit via _exit(1).
|
|
*/
|
|
static void
|
|
StartupPacketTimeoutHandler(void)
|
|
{
|
|
_exit(1);
|
|
}
|
|
|
|
|
|
/*
|
|
* Generate a random cancel key.
|
|
*/
|
|
static bool
|
|
RandomCancelKey(int32 *cancel_key)
|
|
{
|
|
return pg_strong_random(cancel_key, sizeof(int32));
|
|
}
|
|
|
|
/*
|
|
* Count up number of child processes of specified types (dead_end children
|
|
* are always excluded).
|
|
*/
|
|
static int
|
|
CountChildren(int target)
|
|
{
|
|
dlist_iter iter;
|
|
int cnt = 0;
|
|
|
|
dlist_foreach(iter, &BackendList)
|
|
{
|
|
Backend *bp = dlist_container(Backend, elem, iter.cur);
|
|
|
|
if (bp->dead_end)
|
|
continue;
|
|
|
|
/*
|
|
* Since target == BACKEND_TYPE_ALL is the most common case, we test
|
|
* it first and avoid touching shared memory for every child.
|
|
*/
|
|
if (target != BACKEND_TYPE_ALL)
|
|
{
|
|
/*
|
|
* Assign bkend_type for any recently announced WAL Sender
|
|
* processes.
|
|
*/
|
|
if (bp->bkend_type == BACKEND_TYPE_NORMAL &&
|
|
IsPostmasterChildWalSender(bp->child_slot))
|
|
bp->bkend_type = BACKEND_TYPE_WALSND;
|
|
|
|
if (!(target & bp->bkend_type))
|
|
continue;
|
|
}
|
|
|
|
cnt++;
|
|
}
|
|
return cnt;
|
|
}
|
|
|
|
|
|
/*
|
|
* StartChildProcess -- start an auxiliary process for the postmaster
|
|
*
|
|
* "type" determines what kind of child will be started. All child types
|
|
* initially go to AuxiliaryProcessMain, which will handle common setup.
|
|
*
|
|
* Return value of StartChildProcess is subprocess' PID, or 0 if failed
|
|
* to start subprocess.
|
|
*/
|
|
static pid_t
|
|
StartChildProcess(BackendType type)
|
|
{
|
|
pid_t pid;
|
|
|
|
pid = postmaster_child_launch(type, NULL, 0, NULL);
|
|
if (pid < 0)
|
|
{
|
|
/* in parent, fork failed */
|
|
ereport(LOG,
|
|
(errmsg("could not fork \"%s\" process: %m", PostmasterChildName(type))));
|
|
|
|
/*
|
|
* fork failure is fatal during startup, but there's no need to choke
|
|
* immediately if starting other child types fails.
|
|
*/
|
|
if (type == B_STARTUP)
|
|
ExitPostmaster(1);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* in parent, successful fork
|
|
*/
|
|
return pid;
|
|
}
|
|
|
|
/*
|
|
* StartAutovacuumWorker
|
|
* Start an autovac worker process.
|
|
*
|
|
* This function is here because it enters the resulting PID into the
|
|
* postmaster's private backends list.
|
|
*
|
|
* NB -- this code very roughly matches BackendStartup.
|
|
*/
|
|
static void
|
|
StartAutovacuumWorker(void)
|
|
{
|
|
Backend *bn;
|
|
|
|
/*
|
|
* If not in condition to run a process, don't try, but handle it like a
|
|
* fork failure. This does not normally happen, since the signal is only
|
|
* supposed to be sent by autovacuum launcher when it's OK to do it, but
|
|
* we have to check to avoid race-condition problems during DB state
|
|
* changes.
|
|
*/
|
|
if (canAcceptConnections(BACKEND_TYPE_AUTOVAC) == CAC_OK)
|
|
{
|
|
/*
|
|
* Compute the cancel key that will be assigned to this session. We
|
|
* probably don't need cancel keys for autovac workers, but we'd
|
|
* better have something random in the field to prevent unfriendly
|
|
* people from sending cancels to them.
|
|
*/
|
|
if (!RandomCancelKey(&MyCancelKey))
|
|
{
|
|
ereport(LOG,
|
|
(errcode(ERRCODE_INTERNAL_ERROR),
|
|
errmsg("could not generate random cancel key")));
|
|
return;
|
|
}
|
|
|
|
bn = (Backend *) palloc_extended(sizeof(Backend), MCXT_ALLOC_NO_OOM);
|
|
if (bn)
|
|
{
|
|
bn->cancel_key = MyCancelKey;
|
|
|
|
/* Autovac workers are not dead_end and need a child slot */
|
|
bn->dead_end = false;
|
|
bn->child_slot = MyPMChildSlot = AssignPostmasterChildSlot();
|
|
bn->bgworker_notify = false;
|
|
|
|
bn->pid = StartChildProcess(B_AUTOVAC_WORKER);
|
|
if (bn->pid > 0)
|
|
{
|
|
bn->bkend_type = BACKEND_TYPE_AUTOVAC;
|
|
dlist_push_head(&BackendList, &bn->elem);
|
|
#ifdef EXEC_BACKEND
|
|
ShmemBackendArrayAdd(bn);
|
|
#endif
|
|
/* all OK */
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* fork failed, fall through to report -- actual error message was
|
|
* logged by StartChildProcess
|
|
*/
|
|
(void) ReleasePostmasterChildSlot(bn->child_slot);
|
|
pfree(bn);
|
|
}
|
|
else
|
|
ereport(LOG,
|
|
(errcode(ERRCODE_OUT_OF_MEMORY),
|
|
errmsg("out of memory")));
|
|
}
|
|
|
|
/*
|
|
* Report the failure to the launcher, if it's running. (If it's not, we
|
|
* might not even be connected to shared memory, so don't try to call
|
|
* AutoVacWorkerFailed.) Note that we also need to signal it so that it
|
|
* responds to the condition, but we don't do that here, instead waiting
|
|
* for ServerLoop to do it. This way we avoid a ping-pong signaling in
|
|
* quick succession between the autovac launcher and postmaster in case
|
|
* things get ugly.
|
|
*/
|
|
if (AutoVacPID != 0)
|
|
{
|
|
AutoVacWorkerFailed();
|
|
avlauncher_needs_signal = true;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* MaybeStartWalReceiver
|
|
* Start the WAL receiver process, if not running and our state allows.
|
|
*
|
|
* Note: if WalReceiverPID is already nonzero, it might seem that we should
|
|
* clear WalReceiverRequested. However, there's a race condition if the
|
|
* walreceiver terminates and the startup process immediately requests a new
|
|
* one: it's quite possible to get the signal for the request before reaping
|
|
* the dead walreceiver process. Better to risk launching an extra
|
|
* walreceiver than to miss launching one we need. (The walreceiver code
|
|
* has logic to recognize that it should go away if not needed.)
|
|
*/
|
|
static void
|
|
MaybeStartWalReceiver(void)
|
|
{
|
|
if (WalReceiverPID == 0 &&
|
|
(pmState == PM_STARTUP || pmState == PM_RECOVERY ||
|
|
pmState == PM_HOT_STANDBY) &&
|
|
Shutdown <= SmartShutdown)
|
|
{
|
|
WalReceiverPID = StartChildProcess(B_WAL_RECEIVER);
|
|
if (WalReceiverPID != 0)
|
|
WalReceiverRequested = false;
|
|
/* else leave the flag set, so we'll try again later */
|
|
}
|
|
}
|
|
|
|
/*
|
|
* MaybeStartWalSummarizer
|
|
* Start the WAL summarizer process, if not running and our state allows.
|
|
*/
|
|
static void
|
|
MaybeStartWalSummarizer(void)
|
|
{
|
|
if (summarize_wal && WalSummarizerPID == 0 &&
|
|
(pmState == PM_RUN || pmState == PM_HOT_STANDBY) &&
|
|
Shutdown <= SmartShutdown)
|
|
WalSummarizerPID = StartChildProcess(B_WAL_SUMMARIZER);
|
|
}
|
|
|
|
|
|
/*
|
|
* MaybeStartSlotSyncWorker
|
|
* Start the slot sync worker, if not running and our state allows.
|
|
*
|
|
* We allow to start the slot sync worker when we are on a hot standby,
|
|
* fast or immediate shutdown is not in progress, slot sync parameters
|
|
* are configured correctly, and it is the first time of worker's launch,
|
|
* or enough time has passed since the worker was launched last.
|
|
*/
|
|
static void
|
|
MaybeStartSlotSyncWorker(void)
|
|
{
|
|
if (SlotSyncWorkerPID == 0 && pmState == PM_HOT_STANDBY &&
|
|
Shutdown <= SmartShutdown && sync_replication_slots &&
|
|
ValidateSlotSyncParams(LOG) && SlotSyncWorkerCanRestart())
|
|
SlotSyncWorkerPID = StartChildProcess(B_SLOTSYNC_WORKER);
|
|
}
|
|
|
|
/*
|
|
* Create the opts file
|
|
*/
|
|
static bool
|
|
CreateOptsFile(int argc, char *argv[], char *fullprogname)
|
|
{
|
|
FILE *fp;
|
|
int i;
|
|
|
|
#define OPTS_FILE "postmaster.opts"
|
|
|
|
if ((fp = fopen(OPTS_FILE, "w")) == NULL)
|
|
{
|
|
ereport(LOG,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not create file \"%s\": %m", OPTS_FILE)));
|
|
return false;
|
|
}
|
|
|
|
fprintf(fp, "%s", fullprogname);
|
|
for (i = 1; i < argc; i++)
|
|
fprintf(fp, " \"%s\"", argv[i]);
|
|
fputs("\n", fp);
|
|
|
|
if (fclose(fp))
|
|
{
|
|
ereport(LOG,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write file \"%s\": %m", OPTS_FILE)));
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
/*
|
|
* MaxLivePostmasterChildren
|
|
*
|
|
* This reports the number of entries needed in per-child-process arrays
|
|
* (the PMChildFlags array, and if EXEC_BACKEND the ShmemBackendArray).
|
|
* These arrays include regular backends, autovac workers, walsenders
|
|
* and background workers, but not special children nor dead_end children.
|
|
* This allows the arrays to have a fixed maximum size, to wit the same
|
|
* too-many-children limit enforced by canAcceptConnections(). The exact value
|
|
* isn't too critical as long as it's more than MaxBackends.
|
|
*/
|
|
int
|
|
MaxLivePostmasterChildren(void)
|
|
{
|
|
return 2 * (MaxConnections + autovacuum_max_workers + 1 +
|
|
max_wal_senders + max_worker_processes);
|
|
}
|
|
|
|
/*
|
|
* Connect background worker to a database.
|
|
*/
|
|
void
|
|
BackgroundWorkerInitializeConnection(const char *dbname, const char *username, uint32 flags)
|
|
{
|
|
BackgroundWorker *worker = MyBgworkerEntry;
|
|
bits32 init_flags = 0; /* never honor session_preload_libraries */
|
|
|
|
/* ignore datallowconn? */
|
|
if (flags & BGWORKER_BYPASS_ALLOWCONN)
|
|
init_flags |= INIT_PG_OVERRIDE_ALLOW_CONNS;
|
|
/* ignore rolcanlogin? */
|
|
if (flags & BGWORKER_BYPASS_ROLELOGINCHECK)
|
|
init_flags |= INIT_PG_OVERRIDE_ROLE_LOGIN;
|
|
|
|
/* XXX is this the right errcode? */
|
|
if (!(worker->bgw_flags & BGWORKER_BACKEND_DATABASE_CONNECTION))
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("database connection requirement not indicated during registration")));
|
|
|
|
InitPostgres(dbname, InvalidOid, /* database to connect to */
|
|
username, InvalidOid, /* role to connect as */
|
|
init_flags,
|
|
NULL); /* no out_dbname */
|
|
|
|
/* it had better not gotten out of "init" mode yet */
|
|
if (!IsInitProcessingMode())
|
|
ereport(ERROR,
|
|
(errmsg("invalid processing mode in background worker")));
|
|
SetProcessingMode(NormalProcessing);
|
|
}
|
|
|
|
/*
|
|
* Connect background worker to a database using OIDs.
|
|
*/
|
|
void
|
|
BackgroundWorkerInitializeConnectionByOid(Oid dboid, Oid useroid, uint32 flags)
|
|
{
|
|
BackgroundWorker *worker = MyBgworkerEntry;
|
|
bits32 init_flags = 0; /* never honor session_preload_libraries */
|
|
|
|
/* ignore datallowconn? */
|
|
if (flags & BGWORKER_BYPASS_ALLOWCONN)
|
|
init_flags |= INIT_PG_OVERRIDE_ALLOW_CONNS;
|
|
/* ignore rolcanlogin? */
|
|
if (flags & BGWORKER_BYPASS_ROLELOGINCHECK)
|
|
init_flags |= INIT_PG_OVERRIDE_ROLE_LOGIN;
|
|
|
|
/* XXX is this the right errcode? */
|
|
if (!(worker->bgw_flags & BGWORKER_BACKEND_DATABASE_CONNECTION))
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("database connection requirement not indicated during registration")));
|
|
|
|
InitPostgres(NULL, dboid, /* database to connect to */
|
|
NULL, useroid, /* role to connect as */
|
|
init_flags,
|
|
NULL); /* no out_dbname */
|
|
|
|
/* it had better not gotten out of "init" mode yet */
|
|
if (!IsInitProcessingMode())
|
|
ereport(ERROR,
|
|
(errmsg("invalid processing mode in background worker")));
|
|
SetProcessingMode(NormalProcessing);
|
|
}
|
|
|
|
/*
|
|
* Block/unblock signals in a background worker
|
|
*/
|
|
void
|
|
BackgroundWorkerBlockSignals(void)
|
|
{
|
|
sigprocmask(SIG_SETMASK, &BlockSig, NULL);
|
|
}
|
|
|
|
void
|
|
BackgroundWorkerUnblockSignals(void)
|
|
{
|
|
sigprocmask(SIG_SETMASK, &UnBlockSig, NULL);
|
|
}
|
|
|
|
/*
|
|
* Start a new bgworker.
|
|
* Starting time conditions must have been checked already.
|
|
*
|
|
* Returns true on success, false on failure.
|
|
* In either case, update the RegisteredBgWorker's state appropriately.
|
|
*
|
|
* This code is heavily based on autovacuum.c, q.v.
|
|
*/
|
|
static bool
|
|
do_start_bgworker(RegisteredBgWorker *rw)
|
|
{
|
|
pid_t worker_pid;
|
|
|
|
Assert(rw->rw_pid == 0);
|
|
|
|
/*
|
|
* Allocate and assign the Backend element. Note we must do this before
|
|
* forking, so that we can handle failures (out of memory or child-process
|
|
* slots) cleanly.
|
|
*
|
|
* Treat failure as though the worker had crashed. That way, the
|
|
* postmaster will wait a bit before attempting to start it again; if we
|
|
* tried again right away, most likely we'd find ourselves hitting the
|
|
* same resource-exhaustion condition.
|
|
*/
|
|
if (!assign_backendlist_entry(rw))
|
|
{
|
|
rw->rw_crashed_at = GetCurrentTimestamp();
|
|
return false;
|
|
}
|
|
|
|
ereport(DEBUG1,
|
|
(errmsg_internal("starting background worker process \"%s\"",
|
|
rw->rw_worker.bgw_name)));
|
|
|
|
worker_pid = postmaster_child_launch(B_BG_WORKER, (char *) &rw->rw_worker, sizeof(BackgroundWorker), NULL);
|
|
if (worker_pid == -1)
|
|
{
|
|
/* in postmaster, fork failed ... */
|
|
ereport(LOG,
|
|
(errmsg("could not fork background worker process: %m")));
|
|
/* undo what assign_backendlist_entry did */
|
|
ReleasePostmasterChildSlot(rw->rw_child_slot);
|
|
rw->rw_child_slot = 0;
|
|
pfree(rw->rw_backend);
|
|
rw->rw_backend = NULL;
|
|
/* mark entry as crashed, so we'll try again later */
|
|
rw->rw_crashed_at = GetCurrentTimestamp();
|
|
return false;
|
|
}
|
|
|
|
/* in postmaster, fork successful ... */
|
|
rw->rw_pid = worker_pid;
|
|
rw->rw_backend->pid = rw->rw_pid;
|
|
ReportBackgroundWorkerPID(rw);
|
|
/* add new worker to lists of backends */
|
|
dlist_push_head(&BackendList, &rw->rw_backend->elem);
|
|
#ifdef EXEC_BACKEND
|
|
ShmemBackendArrayAdd(rw->rw_backend);
|
|
#endif
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Does the current postmaster state require starting a worker with the
|
|
* specified start_time?
|
|
*/
|
|
static bool
|
|
bgworker_should_start_now(BgWorkerStartTime start_time)
|
|
{
|
|
switch (pmState)
|
|
{
|
|
case PM_NO_CHILDREN:
|
|
case PM_WAIT_DEAD_END:
|
|
case PM_SHUTDOWN_2:
|
|
case PM_SHUTDOWN:
|
|
case PM_WAIT_BACKENDS:
|
|
case PM_STOP_BACKENDS:
|
|
break;
|
|
|
|
case PM_RUN:
|
|
if (start_time == BgWorkerStart_RecoveryFinished)
|
|
return true;
|
|
/* fall through */
|
|
|
|
case PM_HOT_STANDBY:
|
|
if (start_time == BgWorkerStart_ConsistentState)
|
|
return true;
|
|
/* fall through */
|
|
|
|
case PM_RECOVERY:
|
|
case PM_STARTUP:
|
|
case PM_INIT:
|
|
if (start_time == BgWorkerStart_PostmasterStart)
|
|
return true;
|
|
/* fall through */
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Allocate the Backend struct for a connected background worker, but don't
|
|
* add it to the list of backends just yet.
|
|
*
|
|
* On failure, return false without changing any worker state.
|
|
*
|
|
* Some info from the Backend is copied into the passed rw.
|
|
*/
|
|
static bool
|
|
assign_backendlist_entry(RegisteredBgWorker *rw)
|
|
{
|
|
Backend *bn;
|
|
|
|
/*
|
|
* Check that database state allows another connection. Currently the
|
|
* only possible failure is CAC_TOOMANY, so we just log an error message
|
|
* based on that rather than checking the error code precisely.
|
|
*/
|
|
if (canAcceptConnections(BACKEND_TYPE_BGWORKER) != CAC_OK)
|
|
{
|
|
ereport(LOG,
|
|
(errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
|
|
errmsg("no slot available for new background worker process")));
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Compute the cancel key that will be assigned to this session. We
|
|
* probably don't need cancel keys for background workers, but we'd better
|
|
* have something random in the field to prevent unfriendly people from
|
|
* sending cancels to them.
|
|
*/
|
|
if (!RandomCancelKey(&MyCancelKey))
|
|
{
|
|
ereport(LOG,
|
|
(errcode(ERRCODE_INTERNAL_ERROR),
|
|
errmsg("could not generate random cancel key")));
|
|
return false;
|
|
}
|
|
|
|
bn = palloc_extended(sizeof(Backend), MCXT_ALLOC_NO_OOM);
|
|
if (bn == NULL)
|
|
{
|
|
ereport(LOG,
|
|
(errcode(ERRCODE_OUT_OF_MEMORY),
|
|
errmsg("out of memory")));
|
|
return false;
|
|
}
|
|
|
|
bn->cancel_key = MyCancelKey;
|
|
bn->child_slot = MyPMChildSlot = AssignPostmasterChildSlot();
|
|
bn->bkend_type = BACKEND_TYPE_BGWORKER;
|
|
bn->dead_end = false;
|
|
bn->bgworker_notify = false;
|
|
|
|
rw->rw_backend = bn;
|
|
rw->rw_child_slot = bn->child_slot;
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* If the time is right, start background worker(s).
|
|
*
|
|
* As a side effect, the bgworker control variables are set or reset
|
|
* depending on whether more workers may need to be started.
|
|
*
|
|
* We limit the number of workers started per call, to avoid consuming the
|
|
* postmaster's attention for too long when many such requests are pending.
|
|
* As long as StartWorkerNeeded is true, ServerLoop will not block and will
|
|
* call this function again after dealing with any other issues.
|
|
*/
|
|
static void
|
|
maybe_start_bgworkers(void)
|
|
{
|
|
#define MAX_BGWORKERS_TO_LAUNCH 100
|
|
int num_launched = 0;
|
|
TimestampTz now = 0;
|
|
slist_mutable_iter iter;
|
|
|
|
/*
|
|
* During crash recovery, we have no need to be called until the state
|
|
* transition out of recovery.
|
|
*/
|
|
if (FatalError)
|
|
{
|
|
StartWorkerNeeded = false;
|
|
HaveCrashedWorker = false;
|
|
return;
|
|
}
|
|
|
|
/* Don't need to be called again unless we find a reason for it below */
|
|
StartWorkerNeeded = false;
|
|
HaveCrashedWorker = false;
|
|
|
|
slist_foreach_modify(iter, &BackgroundWorkerList)
|
|
{
|
|
RegisteredBgWorker *rw;
|
|
|
|
rw = slist_container(RegisteredBgWorker, rw_lnode, iter.cur);
|
|
|
|
/* ignore if already running */
|
|
if (rw->rw_pid != 0)
|
|
continue;
|
|
|
|
/* if marked for death, clean up and remove from list */
|
|
if (rw->rw_terminate)
|
|
{
|
|
ForgetBackgroundWorker(&iter);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* If this worker has crashed previously, maybe it needs to be
|
|
* restarted (unless on registration it specified it doesn't want to
|
|
* be restarted at all). Check how long ago did a crash last happen.
|
|
* If the last crash is too recent, don't start it right away; let it
|
|
* be restarted once enough time has passed.
|
|
*/
|
|
if (rw->rw_crashed_at != 0)
|
|
{
|
|
if (rw->rw_worker.bgw_restart_time == BGW_NEVER_RESTART)
|
|
{
|
|
int notify_pid;
|
|
|
|
notify_pid = rw->rw_worker.bgw_notify_pid;
|
|
|
|
ForgetBackgroundWorker(&iter);
|
|
|
|
/* Report worker is gone now. */
|
|
if (notify_pid != 0)
|
|
kill(notify_pid, SIGUSR1);
|
|
|
|
continue;
|
|
}
|
|
|
|
/* read system time only when needed */
|
|
if (now == 0)
|
|
now = GetCurrentTimestamp();
|
|
|
|
if (!TimestampDifferenceExceeds(rw->rw_crashed_at, now,
|
|
rw->rw_worker.bgw_restart_time * 1000))
|
|
{
|
|
/* Set flag to remember that we have workers to start later */
|
|
HaveCrashedWorker = true;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
if (bgworker_should_start_now(rw->rw_worker.bgw_start_time))
|
|
{
|
|
/* reset crash time before trying to start worker */
|
|
rw->rw_crashed_at = 0;
|
|
|
|
/*
|
|
* Try to start the worker.
|
|
*
|
|
* On failure, give up processing workers for now, but set
|
|
* StartWorkerNeeded so we'll come back here on the next iteration
|
|
* of ServerLoop to try again. (We don't want to wait, because
|
|
* there might be additional ready-to-run workers.) We could set
|
|
* HaveCrashedWorker as well, since this worker is now marked
|
|
* crashed, but there's no need because the next run of this
|
|
* function will do that.
|
|
*/
|
|
if (!do_start_bgworker(rw))
|
|
{
|
|
StartWorkerNeeded = true;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* If we've launched as many workers as allowed, quit, but have
|
|
* ServerLoop call us again to look for additional ready-to-run
|
|
* workers. There might not be any, but we'll find out the next
|
|
* time we run.
|
|
*/
|
|
if (++num_launched >= MAX_BGWORKERS_TO_LAUNCH)
|
|
{
|
|
StartWorkerNeeded = true;
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* When a backend asks to be notified about worker state changes, we
|
|
* set a flag in its backend entry. The background worker machinery needs
|
|
* to know when such backends exit.
|
|
*/
|
|
bool
|
|
PostmasterMarkPIDForWorkerNotify(int pid)
|
|
{
|
|
dlist_iter iter;
|
|
Backend *bp;
|
|
|
|
dlist_foreach(iter, &BackendList)
|
|
{
|
|
bp = dlist_container(Backend, elem, iter.cur);
|
|
if (bp->pid == pid)
|
|
{
|
|
bp->bgworker_notify = true;
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
#ifdef EXEC_BACKEND
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Size
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ShmemBackendArraySize(void)
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{
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return mul_size(MaxLivePostmasterChildren(), sizeof(Backend));
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}
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void
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ShmemBackendArrayAllocation(void)
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{
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Size size = ShmemBackendArraySize();
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ShmemBackendArray = (Backend *) ShmemAlloc(size);
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/* Mark all slots as empty */
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memset(ShmemBackendArray, 0, size);
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}
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static void
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ShmemBackendArrayAdd(Backend *bn)
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{
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/* The array slot corresponding to my PMChildSlot should be free */
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int i = bn->child_slot - 1;
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Assert(ShmemBackendArray[i].pid == 0);
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ShmemBackendArray[i] = *bn;
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}
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static void
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ShmemBackendArrayRemove(Backend *bn)
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{
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int i = bn->child_slot - 1;
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Assert(ShmemBackendArray[i].pid == bn->pid);
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/* Mark the slot as empty */
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ShmemBackendArray[i].pid = 0;
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}
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#endif /* EXEC_BACKEND */
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#ifdef WIN32
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/*
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* Subset implementation of waitpid() for Windows. We assume pid is -1
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* (that is, check all child processes) and options is WNOHANG (don't wait).
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*/
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static pid_t
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waitpid(pid_t pid, int *exitstatus, int options)
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{
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win32_deadchild_waitinfo *childinfo;
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DWORD exitcode;
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DWORD dwd;
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ULONG_PTR key;
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OVERLAPPED *ovl;
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/* Try to consume one win32_deadchild_waitinfo from the queue. */
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if (!GetQueuedCompletionStatus(win32ChildQueue, &dwd, &key, &ovl, 0))
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{
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errno = EAGAIN;
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return -1;
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}
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childinfo = (win32_deadchild_waitinfo *) key;
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pid = childinfo->procId;
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/*
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* Remove handle from wait - required even though it's set to wait only
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* once
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*/
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UnregisterWaitEx(childinfo->waitHandle, NULL);
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if (!GetExitCodeProcess(childinfo->procHandle, &exitcode))
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{
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/*
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* Should never happen. Inform user and set a fixed exitcode.
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*/
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write_stderr("could not read exit code for process\n");
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exitcode = 255;
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}
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*exitstatus = exitcode;
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/*
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* Close the process handle. Only after this point can the PID can be
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* recycled by the kernel.
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*/
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CloseHandle(childinfo->procHandle);
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/*
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* Free struct that was allocated before the call to
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* RegisterWaitForSingleObject()
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*/
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pfree(childinfo);
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return pid;
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}
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/*
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* Note! Code below executes on a thread pool! All operations must
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* be thread safe! Note that elog() and friends must *not* be used.
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*/
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static void WINAPI
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pgwin32_deadchild_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired)
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{
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/* Should never happen, since we use INFINITE as timeout value. */
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if (TimerOrWaitFired)
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return;
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/*
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* Post the win32_deadchild_waitinfo object for waitpid() to deal with. If
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* that fails, we leak the object, but we also leak a whole process and
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* get into an unrecoverable state, so there's not much point in worrying
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* about that. We'd like to panic, but we can't use that infrastructure
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* from this thread.
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*/
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if (!PostQueuedCompletionStatus(win32ChildQueue,
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0,
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(ULONG_PTR) lpParameter,
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NULL))
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write_stderr("could not post child completion status\n");
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/* Queue SIGCHLD signal. */
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pg_queue_signal(SIGCHLD);
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}
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/*
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* Queue a waiter to signal when this child dies. The wait will be handled
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* automatically by an operating system thread pool. The memory and the
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* process handle will be freed by a later call to waitpid().
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*/
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void
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pgwin32_register_deadchild_callback(HANDLE procHandle, DWORD procId)
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{
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win32_deadchild_waitinfo *childinfo;
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childinfo = palloc(sizeof(win32_deadchild_waitinfo));
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childinfo->procHandle = procHandle;
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childinfo->procId = procId;
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if (!RegisterWaitForSingleObject(&childinfo->waitHandle,
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procHandle,
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pgwin32_deadchild_callback,
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childinfo,
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INFINITE,
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WT_EXECUTEONLYONCE | WT_EXECUTEINWAITTHREAD))
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ereport(FATAL,
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(errmsg_internal("could not register process for wait: error code %lu",
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GetLastError())));
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}
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#endif /* WIN32 */
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/*
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* Initialize one and only handle for monitoring postmaster death.
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*
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* Called once in the postmaster, so that child processes can subsequently
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* monitor if their parent is dead.
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*/
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static void
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InitPostmasterDeathWatchHandle(void)
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{
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#ifndef WIN32
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/*
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* Create a pipe. Postmaster holds the write end of the pipe open
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* (POSTMASTER_FD_OWN), and children hold the read end. Children can pass
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* the read file descriptor to select() to wake up in case postmaster
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* dies, or check for postmaster death with a (read() == 0). Children must
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* close the write end as soon as possible after forking, because EOF
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* won't be signaled in the read end until all processes have closed the
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* write fd. That is taken care of in ClosePostmasterPorts().
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*/
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Assert(MyProcPid == PostmasterPid);
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if (pipe(postmaster_alive_fds) < 0)
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ereport(FATAL,
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(errcode_for_file_access(),
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errmsg_internal("could not create pipe to monitor postmaster death: %m")));
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/* Notify fd.c that we've eaten two FDs for the pipe. */
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ReserveExternalFD();
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ReserveExternalFD();
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/*
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* Set O_NONBLOCK to allow testing for the fd's presence with a read()
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* call.
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*/
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if (fcntl(postmaster_alive_fds[POSTMASTER_FD_WATCH], F_SETFL, O_NONBLOCK) == -1)
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ereport(FATAL,
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(errcode_for_socket_access(),
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errmsg_internal("could not set postmaster death monitoring pipe to nonblocking mode: %m")));
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#else
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/*
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* On Windows, we use a process handle for the same purpose.
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*/
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if (DuplicateHandle(GetCurrentProcess(),
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GetCurrentProcess(),
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GetCurrentProcess(),
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&PostmasterHandle,
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0,
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TRUE,
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DUPLICATE_SAME_ACCESS) == 0)
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ereport(FATAL,
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(errmsg_internal("could not duplicate postmaster handle: error code %lu",
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GetLastError())));
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#endif /* WIN32 */
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}
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