/* ---------- * pgstat.c * * All the statistics collector stuff hacked up in one big, ugly file. * * TODO: - Separate collector, postmaster and backend stuff * into different files. * * - Add some automatic call for pgstat vacuuming. * * - Add a pgstat config column to pg_database, so this * entire thing can be enabled/disabled on a per db basis. * * Copyright (c) 2001-2007, PostgreSQL Global Development Group * * $PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.154 2007/04/30 03:23:49 tgl Exp $ * ---------- */ #include "postgres.h" #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_POLL_H #include #endif #ifdef HAVE_SYS_POLL_H #include #endif #include "pgstat.h" #include "access/heapam.h" #include "access/transam.h" #include "access/xact.h" #include "catalog/pg_database.h" #include "libpq/ip.h" #include "libpq/libpq.h" #include "libpq/pqsignal.h" #include "mb/pg_wchar.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" #include "postmaster/fork_process.h" #include "postmaster/postmaster.h" #include "storage/backendid.h" #include "storage/fd.h" #include "storage/ipc.h" #include "storage/pg_shmem.h" #include "storage/pmsignal.h" #include "utils/memutils.h" #include "utils/ps_status.h" /* ---------- * Paths for the statistics files (relative to installation's $PGDATA). * ---------- */ #define PGSTAT_STAT_FILENAME "global/pgstat.stat" #define PGSTAT_STAT_TMPFILE "global/pgstat.tmp" /* ---------- * Timer definitions. * ---------- */ #define PGSTAT_STAT_INTERVAL 500 /* How often to write the status file; * in milliseconds. */ #define PGSTAT_RESTART_INTERVAL 60 /* How often to attempt to restart a * failed statistics collector; in * seconds. */ #define PGSTAT_SELECT_TIMEOUT 2 /* How often to check for postmaster * death; in seconds. */ /* ---------- * The initial size hints for the hash tables used in the collector. * ---------- */ #define PGSTAT_DB_HASH_SIZE 16 #define PGSTAT_TAB_HASH_SIZE 512 /* ---------- * GUC parameters * ---------- */ bool pgstat_collect_startcollector = true; bool pgstat_collect_resetonpmstart = false; bool pgstat_collect_tuplelevel = false; bool pgstat_collect_blocklevel = false; bool pgstat_collect_querystring = false; /* ---------- * Local data * ---------- */ NON_EXEC_STATIC int pgStatSock = -1; static struct sockaddr_storage pgStatAddr; static time_t last_pgstat_start_time; static bool pgStatRunningInCollector = false; /* * Place where backends store per-table info to be sent to the collector. * We store shared relations separately from non-shared ones, to be able to * send them in separate messages. * * NOTE: once allocated, a PgStat_MsgTabstat struct belonging to a * TabStatArray is never moved or deleted for the life of the backend. * Also, we zero out the t_id fields of the contained PgStat_TableEntry * structs whenever they are not actively in use. This allows PgStat_Info * pointers to be treated as long-lived data, avoiding repeated searches in * pgstat_initstats() when a relation is repeatedly heap_open'd or * index_open'd during a transaction. */ typedef struct TabStatArray { int tsa_alloc; /* num allocated */ int tsa_used; /* num actually used */ PgStat_MsgTabstat **tsa_messages; /* the array itself */ } TabStatArray; #define TABSTAT_QUANTUM 4 /* we alloc this many at a time */ static TabStatArray RegularTabStat = {0, 0, NULL}; static TabStatArray SharedTabStat = {0, 0, NULL}; static int pgStatXactCommit = 0; static int pgStatXactRollback = 0; static MemoryContext pgStatLocalContext = NULL; static HTAB *pgStatDBHash = NULL; static PgBackendStatus *localBackendStatusTable = NULL; static int localNumBackends = 0; /* * BgWriter global statistics counters, from bgwriter.c */ extern PgStat_MsgBgWriter BgWriterStats; /* * Cluster wide statistics, kept in the stats collector. * Contains statistics that are not collected per database * or per table. */ static PgStat_GlobalStats globalStats; static volatile bool need_exit = false; static volatile bool need_statwrite = false; /* ---------- * Local function forward declarations * ---------- */ #ifdef EXEC_BACKEND static pid_t pgstat_forkexec(void); #endif NON_EXEC_STATIC void PgstatCollectorMain(int argc, char *argv[]); static void pgstat_exit(SIGNAL_ARGS); static void force_statwrite(SIGNAL_ARGS); static void pgstat_beshutdown_hook(int code, Datum arg); static PgStat_StatDBEntry *pgstat_get_db_entry(Oid databaseid, bool create); static void pgstat_write_statsfile(void); static HTAB *pgstat_read_statsfile(Oid onlydb); static void backend_read_statsfile(void); static void pgstat_read_current_status(void); static void pgstat_report_one_tabstat(TabStatArray *tsarr, Oid dbid); static HTAB *pgstat_collect_oids(Oid catalogid); static void pgstat_setup_memcxt(void); static void pgstat_setheader(PgStat_MsgHdr *hdr, StatMsgType mtype); static void pgstat_send(void *msg, int len); static void pgstat_recv_tabstat(PgStat_MsgTabstat *msg, int len); static void pgstat_recv_tabpurge(PgStat_MsgTabpurge *msg, int len); static void pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len); static void pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len); static void pgstat_recv_autovac(PgStat_MsgAutovacStart *msg, int len); static void pgstat_recv_vacuum(PgStat_MsgVacuum *msg, int len); static void pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len); static void pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len); /* ------------------------------------------------------------ * Public functions called from postmaster follow * ------------------------------------------------------------ */ /* ---------- * pgstat_init() - * * Called from postmaster at startup. Create the resources required * by the statistics collector process. If unable to do so, do not * fail --- better to let the postmaster start with stats collection * disabled. * ---------- */ void pgstat_init(void) { ACCEPT_TYPE_ARG3 alen; struct addrinfo *addrs = NULL, *addr, hints; int ret; fd_set rset; struct timeval tv; char test_byte; int sel_res; int tries = 0; #define TESTBYTEVAL ((char) 199) /* * Force start of collector daemon if something to collect. Note that * pgstat_collect_querystring is now an independent facility that does not * require the collector daemon. */ if (pgstat_collect_tuplelevel || pgstat_collect_blocklevel) pgstat_collect_startcollector = true; /* * If we don't have to start a collector or should reset the collected * statistics on postmaster start, simply remove the stats file. */ if (!pgstat_collect_startcollector || pgstat_collect_resetonpmstart) pgstat_reset_all(); /* * Nothing else required if collector will not get started */ if (!pgstat_collect_startcollector) return; /* * Create the UDP socket for sending and receiving statistic messages */ hints.ai_flags = AI_PASSIVE; hints.ai_family = PF_UNSPEC; hints.ai_socktype = SOCK_DGRAM; hints.ai_protocol = 0; hints.ai_addrlen = 0; hints.ai_addr = NULL; hints.ai_canonname = NULL; hints.ai_next = NULL; ret = pg_getaddrinfo_all("localhost", NULL, &hints, &addrs); if (ret || !addrs) { ereport(LOG, (errmsg("could not resolve \"localhost\": %s", gai_strerror(ret)))); goto startup_failed; } /* * On some platforms, pg_getaddrinfo_all() may return multiple addresses * only one of which will actually work (eg, both IPv6 and IPv4 addresses * when kernel will reject IPv6). Worse, the failure may occur at the * bind() or perhaps even connect() stage. So we must loop through the * results till we find a working combination. We will generate LOG * messages, but no error, for bogus combinations. */ for (addr = addrs; addr; addr = addr->ai_next) { #ifdef HAVE_UNIX_SOCKETS /* Ignore AF_UNIX sockets, if any are returned. */ if (addr->ai_family == AF_UNIX) continue; #endif if (++tries > 1) ereport(LOG, (errmsg("trying another address for the statistics collector"))); /* * Create the socket. */ if ((pgStatSock = socket(addr->ai_family, SOCK_DGRAM, 0)) < 0) { ereport(LOG, (errcode_for_socket_access(), errmsg("could not create socket for statistics collector: %m"))); continue; } /* * Bind it to a kernel assigned port on localhost and get the assigned * port via getsockname(). */ if (bind(pgStatSock, addr->ai_addr, addr->ai_addrlen) < 0) { ereport(LOG, (errcode_for_socket_access(), errmsg("could not bind socket for statistics collector: %m"))); closesocket(pgStatSock); pgStatSock = -1; continue; } alen = sizeof(pgStatAddr); if (getsockname(pgStatSock, (struct sockaddr *) & pgStatAddr, &alen) < 0) { ereport(LOG, (errcode_for_socket_access(), errmsg("could not get address of socket for statistics collector: %m"))); closesocket(pgStatSock); pgStatSock = -1; continue; } /* * Connect the socket to its own address. This saves a few cycles by * not having to respecify the target address on every send. This also * provides a kernel-level check that only packets from this same * address will be received. */ if (connect(pgStatSock, (struct sockaddr *) & pgStatAddr, alen) < 0) { ereport(LOG, (errcode_for_socket_access(), errmsg("could not connect socket for statistics collector: %m"))); closesocket(pgStatSock); pgStatSock = -1; continue; } /* * Try to send and receive a one-byte test message on the socket. This * is to catch situations where the socket can be created but will not * actually pass data (for instance, because kernel packet filtering * rules prevent it). */ test_byte = TESTBYTEVAL; retry1: if (send(pgStatSock, &test_byte, 1, 0) != 1) { if (errno == EINTR) goto retry1; /* if interrupted, just retry */ ereport(LOG, (errcode_for_socket_access(), errmsg("could not send test message on socket for statistics collector: %m"))); closesocket(pgStatSock); pgStatSock = -1; continue; } /* * There could possibly be a little delay before the message can be * received. We arbitrarily allow up to half a second before deciding * it's broken. */ for (;;) /* need a loop to handle EINTR */ { FD_ZERO(&rset); FD_SET(pgStatSock, &rset); tv.tv_sec = 0; tv.tv_usec = 500000; sel_res = select(pgStatSock + 1, &rset, NULL, NULL, &tv); if (sel_res >= 0 || errno != EINTR) break; } if (sel_res < 0) { ereport(LOG, (errcode_for_socket_access(), errmsg("select() failed in statistics collector: %m"))); closesocket(pgStatSock); pgStatSock = -1; continue; } if (sel_res == 0 || !FD_ISSET(pgStatSock, &rset)) { /* * This is the case we actually think is likely, so take pains to * give a specific message for it. * * errno will not be set meaningfully here, so don't use it. */ ereport(LOG, (errcode(ERRCODE_CONNECTION_FAILURE), errmsg("test message did not get through on socket for statistics collector"))); closesocket(pgStatSock); pgStatSock = -1; continue; } test_byte++; /* just make sure variable is changed */ retry2: if (recv(pgStatSock, &test_byte, 1, 0) != 1) { if (errno == EINTR) goto retry2; /* if interrupted, just retry */ ereport(LOG, (errcode_for_socket_access(), errmsg("could not receive test message on socket for statistics collector: %m"))); closesocket(pgStatSock); pgStatSock = -1; continue; } if (test_byte != TESTBYTEVAL) /* strictly paranoia ... */ { ereport(LOG, (errcode(ERRCODE_INTERNAL_ERROR), errmsg("incorrect test message transmission on socket for statistics collector"))); closesocket(pgStatSock); pgStatSock = -1; continue; } /* If we get here, we have a working socket */ break; } /* Did we find a working address? */ if (!addr || pgStatSock < 0) goto startup_failed; /* * Set the socket to non-blocking IO. This ensures that if the collector * falls behind, statistics messages will be discarded; backends won't * block waiting to send messages to the collector. */ if (!pg_set_noblock(pgStatSock)) { ereport(LOG, (errcode_for_socket_access(), errmsg("could not set statistics collector socket to nonblocking mode: %m"))); goto startup_failed; } pg_freeaddrinfo_all(hints.ai_family, addrs); return; startup_failed: ereport(LOG, (errmsg("disabling statistics collector for lack of working socket"))); if (addrs) pg_freeaddrinfo_all(hints.ai_family, addrs); if (pgStatSock >= 0) closesocket(pgStatSock); pgStatSock = -1; /* Adjust GUC variables to suppress useless activity */ pgstat_collect_startcollector = false; pgstat_collect_tuplelevel = false; pgstat_collect_blocklevel = false; } /* * pgstat_reset_all() - * * Remove the stats file. This is used on server start if the * stats_reset_on_server_start feature is enabled, or if WAL * recovery is needed after a crash. */ void pgstat_reset_all(void) { unlink(PGSTAT_STAT_FILENAME); } #ifdef EXEC_BACKEND /* * pgstat_forkexec() - * * Format up the arglist for, then fork and exec, statistics collector process */ static pid_t pgstat_forkexec(void) { char *av[10]; int ac = 0; av[ac++] = "postgres"; av[ac++] = "--forkcol"; av[ac++] = NULL; /* filled in by postmaster_forkexec */ av[ac] = NULL; Assert(ac < lengthof(av)); return postmaster_forkexec(ac, av); } #endif /* EXEC_BACKEND */ /* ---------- * pgstat_start() - * * Called from postmaster at startup or after an existing collector * died. Attempt to fire up a fresh statistics collector. * * Returns PID of child process, or 0 if fail. * * Note: if fail, we will be called again from the postmaster main loop. * ---------- */ int pgstat_start(void) { time_t curtime; pid_t pgStatPid; /* * Do nothing if no collector needed */ if (!pgstat_collect_startcollector) return 0; /* * Do nothing if too soon since last collector start. This is a safety * valve to protect against continuous respawn attempts if the collector * is dying immediately at launch. Note that since we will be re-called * from the postmaster main loop, we will get another chance later. */ curtime = time(NULL); if ((unsigned int) (curtime - last_pgstat_start_time) < (unsigned int) PGSTAT_RESTART_INTERVAL) return 0; last_pgstat_start_time = curtime; /* * Check that the socket is there, else pgstat_init failed. */ if (pgStatSock < 0) { ereport(LOG, (errmsg("statistics collector startup skipped"))); /* * We can only get here if someone tries to manually turn * pgstat_collect_startcollector on after it had been off. */ pgstat_collect_startcollector = false; return 0; } /* * Okay, fork off the collector. */ #ifdef EXEC_BACKEND switch ((pgStatPid = pgstat_forkexec())) #else switch ((pgStatPid = fork_process())) #endif { case -1: ereport(LOG, (errmsg("could not fork statistics collector: %m"))); return 0; #ifndef EXEC_BACKEND case 0: /* in postmaster child ... */ /* Close the postmaster's sockets */ ClosePostmasterPorts(false); /* Lose the postmaster's on-exit routines */ on_exit_reset(); /* Drop our connection to postmaster's shared memory, as well */ PGSharedMemoryDetach(); PgstatCollectorMain(0, NULL); break; #endif default: return (int) pgStatPid; } /* shouldn't get here */ return 0; } void allow_immediate_pgstat_restart(void) { last_pgstat_start_time = 0; } /* ------------------------------------------------------------ * Public functions used by backends follow *------------------------------------------------------------ */ /* ---------- * pgstat_report_tabstat() - * * Called from tcop/postgres.c to send the so far collected per-table * access statistics to the collector. Note that this is called only * when not within a transaction, so it is fair to use transaction stop * time as an approximation of current time. * ---------- */ void pgstat_report_tabstat(void) { static TimestampTz last_report = 0; TimestampTz now; /* Don't expend a clock check if nothing to do */ if (RegularTabStat.tsa_used == 0 && SharedTabStat.tsa_used == 0) return; /* * Don't send a message unless it's been at least PGSTAT_STAT_INTERVAL * msec since we last sent one. */ now = GetCurrentTransactionStopTimestamp(); if (!TimestampDifferenceExceeds(last_report, now, PGSTAT_STAT_INTERVAL)) return; last_report = now; /* * For each message buffer used during the last queries, set the header * fields and send it out; then mark the entries unused. */ pgstat_report_one_tabstat(&RegularTabStat, MyDatabaseId); pgstat_report_one_tabstat(&SharedTabStat, InvalidOid); } static void pgstat_report_one_tabstat(TabStatArray *tsarr, Oid dbid) { int i; for (i = 0; i < tsarr->tsa_used; i++) { PgStat_MsgTabstat *tsmsg = tsarr->tsa_messages[i]; int n; int len; n = tsmsg->m_nentries; len = offsetof(PgStat_MsgTabstat, m_entry[0]) + n * sizeof(PgStat_TableEntry); tsmsg->m_xact_commit = pgStatXactCommit; tsmsg->m_xact_rollback = pgStatXactRollback; pgStatXactCommit = 0; pgStatXactRollback = 0; /* * It's unlikely we'd get here with no socket, but maybe not * impossible */ if (pgStatSock >= 0) { pgstat_setheader(&tsmsg->m_hdr, PGSTAT_MTYPE_TABSTAT); tsmsg->m_databaseid = dbid; pgstat_send(tsmsg, len); } /* * Zero out the entries, to mark them unused and prepare them * for next use. */ MemSet(tsmsg, 0, len); } tsarr->tsa_used = 0; } /* ---------- * pgstat_vacuum_tabstat() - * * Will tell the collector about objects he can get rid of. * ---------- */ void pgstat_vacuum_tabstat(void) { HTAB *htab; PgStat_MsgTabpurge msg; HASH_SEQ_STATUS hstat; PgStat_StatDBEntry *dbentry; PgStat_StatTabEntry *tabentry; int len; if (pgStatSock < 0) return; /* * If not done for this transaction, read the statistics collector stats * file into some hash tables. */ backend_read_statsfile(); /* * Read pg_database and make a list of OIDs of all existing databases */ htab = pgstat_collect_oids(DatabaseRelationId); /* * Search the database hash table for dead databases and tell the * collector to drop them. */ hash_seq_init(&hstat, pgStatDBHash); while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL) { Oid dbid = dbentry->databaseid; CHECK_FOR_INTERRUPTS(); if (hash_search(htab, (void *) &dbid, HASH_FIND, NULL) == NULL) pgstat_drop_database(dbid); } /* Clean up */ hash_destroy(htab); /* * Lookup our own database entry; if not found, nothing more to do. */ dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash, (void *) &MyDatabaseId, HASH_FIND, NULL); if (dbentry == NULL || dbentry->tables == NULL) return; /* * Similarly to above, make a list of all known relations in this DB. */ htab = pgstat_collect_oids(RelationRelationId); /* * Initialize our messages table counter to zero */ msg.m_nentries = 0; /* * Check for all tables listed in stats hashtable if they still exist. */ hash_seq_init(&hstat, dbentry->tables); while ((tabentry = (PgStat_StatTabEntry *) hash_seq_search(&hstat)) != NULL) { Oid tabid = tabentry->tableid; CHECK_FOR_INTERRUPTS(); if (hash_search(htab, (void *) &tabid, HASH_FIND, NULL) != NULL) continue; /* * Not there, so add this table's Oid to the message */ msg.m_tableid[msg.m_nentries++] = tabid; /* * If the message is full, send it out and reinitialize to empty */ if (msg.m_nentries >= PGSTAT_NUM_TABPURGE) { len = offsetof(PgStat_MsgTabpurge, m_tableid[0]) +msg.m_nentries * sizeof(Oid); pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TABPURGE); msg.m_databaseid = MyDatabaseId; pgstat_send(&msg, len); msg.m_nentries = 0; } } /* * Send the rest */ if (msg.m_nentries > 0) { len = offsetof(PgStat_MsgTabpurge, m_tableid[0]) +msg.m_nentries * sizeof(Oid); pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TABPURGE); msg.m_databaseid = MyDatabaseId; pgstat_send(&msg, len); } /* Clean up */ hash_destroy(htab); } /* ---------- * pgstat_collect_oids() - * * Collect the OIDs of either all databases or all tables, according to * the parameter, into a temporary hash table. Caller should hash_destroy * the result when done with it. * ---------- */ static HTAB * pgstat_collect_oids(Oid catalogid) { HTAB *htab; HASHCTL hash_ctl; Relation rel; HeapScanDesc scan; HeapTuple tup; memset(&hash_ctl, 0, sizeof(hash_ctl)); hash_ctl.keysize = sizeof(Oid); hash_ctl.entrysize = sizeof(Oid); hash_ctl.hash = oid_hash; htab = hash_create("Temporary table of OIDs", PGSTAT_TAB_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_FUNCTION); rel = heap_open(catalogid, AccessShareLock); scan = heap_beginscan(rel, SnapshotNow, 0, NULL); while ((tup = heap_getnext(scan, ForwardScanDirection)) != NULL) { Oid thisoid = HeapTupleGetOid(tup); CHECK_FOR_INTERRUPTS(); (void) hash_search(htab, (void *) &thisoid, HASH_ENTER, NULL); } heap_endscan(scan); heap_close(rel, AccessShareLock); return htab; } /* ---------- * pgstat_drop_database() - * * Tell the collector that we just dropped a database. * (If the message gets lost, we will still clean the dead DB eventually * via future invocations of pgstat_vacuum_tabstat().) * ---------- */ void pgstat_drop_database(Oid databaseid) { PgStat_MsgDropdb msg; if (pgStatSock < 0) return; pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_DROPDB); msg.m_databaseid = databaseid; pgstat_send(&msg, sizeof(msg)); } /* ---------- * pgstat_drop_relation() - * * Tell the collector that we just dropped a relation. * (If the message gets lost, we will still clean the dead entry eventually * via future invocations of pgstat_vacuum_tabstat().) * ---------- */ void pgstat_drop_relation(Oid relid) { PgStat_MsgTabpurge msg; int len; if (pgStatSock < 0) return; msg.m_tableid[0] = relid; msg.m_nentries = 1; len = offsetof(PgStat_MsgTabpurge, m_tableid[0]) +sizeof(Oid); pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TABPURGE); msg.m_databaseid = MyDatabaseId; pgstat_send(&msg, len); } /* ---------- * pgstat_reset_counters() - * * Tell the statistics collector to reset counters for our database. * ---------- */ void pgstat_reset_counters(void) { PgStat_MsgResetcounter msg; if (pgStatSock < 0) return; if (!superuser()) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("must be superuser to reset statistics counters"))); pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETCOUNTER); msg.m_databaseid = MyDatabaseId; pgstat_send(&msg, sizeof(msg)); } /* ---------- * pgstat_report_autovac() - * * Called from autovacuum.c to report startup of an autovacuum process. * We are called before InitPostgres is done, so can't rely on MyDatabaseId; * the db OID must be passed in, instead. * ---------- */ void pgstat_report_autovac(Oid dboid) { PgStat_MsgAutovacStart msg; if (pgStatSock < 0) return; pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_AUTOVAC_START); msg.m_databaseid = dboid; msg.m_start_time = GetCurrentTimestamp(); pgstat_send(&msg, sizeof(msg)); } /* --------- * pgstat_report_vacuum() - * * Tell the collector about the table we just vacuumed. * --------- */ void pgstat_report_vacuum(Oid tableoid, bool shared, bool analyze, PgStat_Counter tuples) { PgStat_MsgVacuum msg; if (pgStatSock < 0 || !pgstat_collect_tuplelevel) return; pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_VACUUM); msg.m_databaseid = shared ? InvalidOid : MyDatabaseId; msg.m_tableoid = tableoid; msg.m_analyze = analyze; msg.m_autovacuum = IsAutoVacuumWorkerProcess(); /* is this autovacuum? */ msg.m_vacuumtime = GetCurrentTimestamp(); msg.m_tuples = tuples; pgstat_send(&msg, sizeof(msg)); } /* -------- * pgstat_report_analyze() - * * Tell the collector about the table we just analyzed. * -------- */ void pgstat_report_analyze(Oid tableoid, bool shared, PgStat_Counter livetuples, PgStat_Counter deadtuples) { PgStat_MsgAnalyze msg; if (pgStatSock < 0 || !pgstat_collect_tuplelevel) return; pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_ANALYZE); msg.m_databaseid = shared ? InvalidOid : MyDatabaseId; msg.m_tableoid = tableoid; msg.m_autovacuum = IsAutoVacuumWorkerProcess(); /* is this autovacuum? */ msg.m_analyzetime = GetCurrentTimestamp(); msg.m_live_tuples = livetuples; msg.m_dead_tuples = deadtuples; pgstat_send(&msg, sizeof(msg)); } /* ---------- * pgstat_ping() - * * Send some junk data to the collector to increase traffic. * ---------- */ void pgstat_ping(void) { PgStat_MsgDummy msg; if (pgStatSock < 0) return; pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_DUMMY); pgstat_send(&msg, sizeof(msg)); } /* * Enlarge a TabStatArray */ static void more_tabstat_space(TabStatArray *tsarr) { PgStat_MsgTabstat *newMessages; PgStat_MsgTabstat **msgArray; int newAlloc; int i; AssertArg(PointerIsValid(tsarr)); newAlloc = tsarr->tsa_alloc + TABSTAT_QUANTUM; /* Create (another) quantum of message buffers, and zero them */ newMessages = (PgStat_MsgTabstat *) MemoryContextAllocZero(TopMemoryContext, sizeof(PgStat_MsgTabstat) * TABSTAT_QUANTUM); /* Create or enlarge the pointer array */ if (tsarr->tsa_messages == NULL) msgArray = (PgStat_MsgTabstat **) MemoryContextAlloc(TopMemoryContext, sizeof(PgStat_MsgTabstat *) * newAlloc); else msgArray = (PgStat_MsgTabstat **) repalloc(tsarr->tsa_messages, sizeof(PgStat_MsgTabstat *) * newAlloc); for (i = 0; i < TABSTAT_QUANTUM; i++) msgArray[tsarr->tsa_alloc + i] = newMessages++; tsarr->tsa_messages = msgArray; tsarr->tsa_alloc = newAlloc; Assert(tsarr->tsa_used < tsarr->tsa_alloc); } /* ---------- * pgstat_initstats() - * * Called from various places usually dealing with initialization * of Relation or Scan structures. The data placed into these * structures from here tell where later to count for buffer reads, * scans and tuples fetched. * * NOTE: PgStat_Info pointers in scan structures are really redundant * with those in relcache entries. The passed stats pointer might point * either to the Relation struct's own pgstat_info field, or to one in * a scan structure; we'll set the Relation pg_statinfo and copy it to * the scan struct. * * We assume that a relcache entry's pgstat_info field is zeroed by * relcache.c when the relcache entry is made; thereafter it is long-lived * data. We can avoid repeated searches of the TabStat arrays when the * same relation is touched repeatedly within a transaction. * ---------- */ void pgstat_initstats(PgStat_Info *stats, Relation rel) { Oid rel_id = rel->rd_id; PgStat_TableEntry *useent; TabStatArray *tsarr; PgStat_MsgTabstat *tsmsg; int mb; int i; if (pgStatSock < 0 || !(pgstat_collect_tuplelevel || pgstat_collect_blocklevel)) { /* We're not counting at all. */ stats->tabentry = NULL; return; } /* * If we already set up this relation in the current transaction, * just copy the pointer. */ if (rel->pgstat_info.tabentry != NULL && ((PgStat_TableEntry *) rel->pgstat_info.tabentry)->t_id == rel_id) { stats->tabentry = rel->pgstat_info.tabentry; return; } /* * Search the already-used message slots for this relation. */ tsarr = rel->rd_rel->relisshared ? &SharedTabStat : &RegularTabStat; for (mb = 0; mb < tsarr->tsa_used; mb++) { tsmsg = tsarr->tsa_messages[mb]; for (i = tsmsg->m_nentries; --i >= 0;) { if (tsmsg->m_entry[i].t_id == rel_id) { rel->pgstat_info.tabentry = (void *) &(tsmsg->m_entry[i]); stats->tabentry = rel->pgstat_info.tabentry; return; } } if (tsmsg->m_nentries >= PGSTAT_NUM_TABENTRIES) continue; /* * Not found, but found a message buffer with an empty slot instead. * Fine, let's use this one. We assume the entry was already zeroed, * either at creation or after last use. */ i = tsmsg->m_nentries++; useent = &tsmsg->m_entry[i]; useent->t_id = rel_id; rel->pgstat_info.tabentry = (void *) useent; stats->tabentry = rel->pgstat_info.tabentry; return; } /* * If we ran out of message buffers, we just allocate more. */ if (tsarr->tsa_used >= tsarr->tsa_alloc) more_tabstat_space(tsarr); /* * Use the first entry of the next message buffer. */ mb = tsarr->tsa_used++; tsmsg = tsarr->tsa_messages[mb]; tsmsg->m_nentries = 1; useent = &tsmsg->m_entry[0]; useent->t_id = rel_id; rel->pgstat_info.tabentry = (void *) useent; stats->tabentry = rel->pgstat_info.tabentry; } /* ---------- * pgstat_count_xact_commit() - * * Called from access/transam/xact.c to count transaction commits. * ---------- */ void pgstat_count_xact_commit(void) { if (!pgstat_collect_tuplelevel && !pgstat_collect_blocklevel) return; pgStatXactCommit++; /* * If there was no relation activity yet, just make one existing message * buffer used without slots, causing the next report to tell new * xact-counters. */ if (RegularTabStat.tsa_alloc == 0) more_tabstat_space(&RegularTabStat); if (RegularTabStat.tsa_used == 0) { RegularTabStat.tsa_used++; RegularTabStat.tsa_messages[0]->m_nentries = 0; } } /* ---------- * pgstat_count_xact_rollback() - * * Called from access/transam/xact.c to count transaction rollbacks. * ---------- */ void pgstat_count_xact_rollback(void) { if (!pgstat_collect_tuplelevel && !pgstat_collect_blocklevel) return; pgStatXactRollback++; /* * If there was no relation activity yet, just make one existing message * buffer used without slots, causing the next report to tell new * xact-counters. */ if (RegularTabStat.tsa_alloc == 0) more_tabstat_space(&RegularTabStat); if (RegularTabStat.tsa_used == 0) { RegularTabStat.tsa_used++; RegularTabStat.tsa_messages[0]->m_nentries = 0; } } /* ---------- * pgstat_fetch_stat_dbentry() - * * Support function for the SQL-callable pgstat* functions. Returns * the collected statistics for one database or NULL. NULL doesn't mean * that the database doesn't exist, it is just not yet known by the * collector, so the caller is better off to report ZERO instead. * ---------- */ PgStat_StatDBEntry * pgstat_fetch_stat_dbentry(Oid dbid) { /* * If not done for this transaction, read the statistics collector stats * file into some hash tables. */ backend_read_statsfile(); /* * Lookup the requested database; return NULL if not found */ return (PgStat_StatDBEntry *) hash_search(pgStatDBHash, (void *) &dbid, HASH_FIND, NULL); } /* ---------- * pgstat_fetch_stat_tabentry() - * * Support function for the SQL-callable pgstat* functions. Returns * the collected statistics for one table or NULL. NULL doesn't mean * that the table doesn't exist, it is just not yet known by the * collector, so the caller is better off to report ZERO instead. * ---------- */ PgStat_StatTabEntry * pgstat_fetch_stat_tabentry(Oid relid) { Oid dbid; PgStat_StatDBEntry *dbentry; PgStat_StatTabEntry *tabentry; /* * If not done for this transaction, read the statistics collector stats * file into some hash tables. */ backend_read_statsfile(); /* * Lookup our database, then look in its table hash table. */ dbid = MyDatabaseId; dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash, (void *) &dbid, HASH_FIND, NULL); if (dbentry != NULL && dbentry->tables != NULL) { tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables, (void *) &relid, HASH_FIND, NULL); if (tabentry) return tabentry; } /* * If we didn't find it, maybe it's a shared table. */ dbid = InvalidOid; dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash, (void *) &dbid, HASH_FIND, NULL); if (dbentry != NULL && dbentry->tables != NULL) { tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables, (void *) &relid, HASH_FIND, NULL); if (tabentry) return tabentry; } return NULL; } /* ---------- * pgstat_fetch_stat_beentry() - * * Support function for the SQL-callable pgstat* functions. Returns * our local copy of the current-activity entry for one backend. * * NB: caller is responsible for a check if the user is permitted to see * this info (especially the querystring). * ---------- */ PgBackendStatus * pgstat_fetch_stat_beentry(int beid) { pgstat_read_current_status(); if (beid < 1 || beid > localNumBackends) return NULL; return &localBackendStatusTable[beid - 1]; } /* ---------- * pgstat_fetch_stat_numbackends() - * * Support function for the SQL-callable pgstat* functions. Returns * the maximum current backend id. * ---------- */ int pgstat_fetch_stat_numbackends(void) { pgstat_read_current_status(); return localNumBackends; } /* * --------- * pgstat_fetch_global() - * * Support function for the SQL-callable pgstat* functions. Returns * a pointer to the global statistics struct. * --------- */ PgStat_GlobalStats * pgstat_fetch_global(void) { backend_read_statsfile(); return &globalStats; } /* ------------------------------------------------------------ * Functions for management of the shared-memory PgBackendStatus array * ------------------------------------------------------------ */ static PgBackendStatus *BackendStatusArray = NULL; static PgBackendStatus *MyBEEntry = NULL; /* * Report shared-memory space needed by CreateSharedBackendStatus. */ Size BackendStatusShmemSize(void) { Size size; size = mul_size(sizeof(PgBackendStatus), MaxBackends); return size; } /* * Initialize the shared status array during postmaster startup. */ void CreateSharedBackendStatus(void) { Size size = BackendStatusShmemSize(); bool found; /* Create or attach to the shared array */ BackendStatusArray = (PgBackendStatus *) ShmemInitStruct("Backend Status Array", size, &found); if (!found) { /* * We're the first - initialize. */ MemSet(BackendStatusArray, 0, size); } } /* ---------- * pgstat_bestart() - * * Initialize this backend's entry in the PgBackendStatus array, * and set up an on-proc-exit hook that will clear it again. * Called from InitPostgres. MyBackendId and MyDatabaseId must be set. * ---------- */ void pgstat_bestart(void) { volatile PgBackendStatus *beentry; TimestampTz proc_start_timestamp; Oid userid; SockAddr clientaddr; Assert(MyBackendId >= 1 && MyBackendId <= MaxBackends); MyBEEntry = &BackendStatusArray[MyBackendId - 1]; /* * To minimize the time spent modifying the entry, fetch all the needed * data first. * * If we have a MyProcPort, use its session start time (for consistency, * and to save a kernel call). */ if (MyProcPort) proc_start_timestamp = MyProcPort->SessionStartTime; else proc_start_timestamp = GetCurrentTimestamp(); userid = GetSessionUserId(); /* * We may not have a MyProcPort (eg, if this is the autovacuum process). * If so, use all-zeroes client address, which is dealt with specially in * pg_stat_get_backend_client_addr and pg_stat_get_backend_client_port. */ if (MyProcPort) memcpy(&clientaddr, &MyProcPort->raddr, sizeof(clientaddr)); else MemSet(&clientaddr, 0, sizeof(clientaddr)); /* * Initialize my status entry, following the protocol of bumping * st_changecount before and after; and make sure it's even afterwards. We * use a volatile pointer here to ensure the compiler doesn't try to get * cute. */ beentry = MyBEEntry; do { beentry->st_changecount++; } while ((beentry->st_changecount & 1) == 0); beentry->st_procpid = MyProcPid; beentry->st_proc_start_timestamp = proc_start_timestamp; beentry->st_activity_start_timestamp = 0; beentry->st_txn_start_timestamp = 0; beentry->st_databaseid = MyDatabaseId; beentry->st_userid = userid; beentry->st_clientaddr = clientaddr; beentry->st_waiting = false; beentry->st_activity[0] = '\0'; /* Also make sure the last byte in the string area is always 0 */ beentry->st_activity[PGBE_ACTIVITY_SIZE - 1] = '\0'; beentry->st_changecount++; Assert((beentry->st_changecount & 1) == 0); /* * Set up a process-exit hook to clean up. */ on_shmem_exit(pgstat_beshutdown_hook, 0); } /* * Shut down a single backend's statistics reporting at process exit. * * Flush any remaining statistics counts out to the collector. * Without this, operations triggered during backend exit (such as * temp table deletions) won't be counted. * * Lastly, clear out our entry in the PgBackendStatus array. */ static void pgstat_beshutdown_hook(int code, Datum arg) { volatile PgBackendStatus *beentry = MyBEEntry; pgstat_report_tabstat(); /* * Clear my status entry, following the protocol of bumping st_changecount * before and after. We use a volatile pointer here to ensure the * compiler doesn't try to get cute. */ beentry->st_changecount++; beentry->st_procpid = 0; /* mark invalid */ beentry->st_changecount++; Assert((beentry->st_changecount & 1) == 0); } /* ---------- * pgstat_report_activity() - * * Called from tcop/postgres.c to report what the backend is actually doing * (usually "" or the start of the query to be executed). * ---------- */ void pgstat_report_activity(const char *cmd_str) { volatile PgBackendStatus *beentry = MyBEEntry; TimestampTz start_timestamp; int len; if (!pgstat_collect_querystring || !beentry) return; /* * To minimize the time spent modifying the entry, fetch all the needed * data first. */ start_timestamp = GetCurrentStatementStartTimestamp(); len = strlen(cmd_str); len = pg_mbcliplen(cmd_str, len, PGBE_ACTIVITY_SIZE - 1); /* * Update my status entry, following the protocol of bumping * st_changecount before and after. We use a volatile pointer here to * ensure the compiler doesn't try to get cute. */ beentry->st_changecount++; beentry->st_activity_start_timestamp = start_timestamp; memcpy((char *) beentry->st_activity, cmd_str, len); beentry->st_activity[len] = '\0'; beentry->st_changecount++; Assert((beentry->st_changecount & 1) == 0); } /* * Set the current transaction start timestamp to the specified * value. If there is no current active transaction, this is signified * by 0. */ void pgstat_report_txn_timestamp(TimestampTz tstamp) { volatile PgBackendStatus *beentry = MyBEEntry; if (!pgstat_collect_querystring || !beentry) return; /* * Update my status entry, following the protocol of bumping * st_changecount before and after. We use a volatile pointer * here to ensure the compiler doesn't try to get cute. */ beentry->st_changecount++; beentry->st_txn_start_timestamp = tstamp; beentry->st_changecount++; Assert((beentry->st_changecount & 1) == 0); } /* ---------- * pgstat_report_waiting() - * * Called from lock manager to report beginning or end of a lock wait. * * NB: this *must* be able to survive being called before MyBEEntry has been * initialized. * ---------- */ void pgstat_report_waiting(bool waiting) { volatile PgBackendStatus *beentry = MyBEEntry; if (!pgstat_collect_querystring || !beentry) return; /* * Since this is a single-byte field in a struct that only this process * may modify, there seems no need to bother with the st_changecount * protocol. The update must appear atomic in any case. */ beentry->st_waiting = waiting; } /* ---------- * pgstat_read_current_status() - * * Copy the current contents of the PgBackendStatus array to local memory, * if not already done in this transaction. * ---------- */ static void pgstat_read_current_status(void) { volatile PgBackendStatus *beentry; PgBackendStatus *localtable; PgBackendStatus *localentry; int i; Assert(!pgStatRunningInCollector); if (localBackendStatusTable) return; /* already done */ pgstat_setup_memcxt(); localtable = (PgBackendStatus *) MemoryContextAlloc(pgStatLocalContext, sizeof(PgBackendStatus) * MaxBackends); localNumBackends = 0; beentry = BackendStatusArray; localentry = localtable; for (i = 1; i <= MaxBackends; i++) { /* * Follow the protocol of retrying if st_changecount changes while we * copy the entry, or if it's odd. (The check for odd is needed to * cover the case where we are able to completely copy the entry while * the source backend is between increment steps.) We use a volatile * pointer here to ensure the compiler doesn't try to get cute. */ for (;;) { int save_changecount = beentry->st_changecount; /* * XXX if PGBE_ACTIVITY_SIZE is really large, it might be best to * use strcpy not memcpy for copying the activity string? */ memcpy(localentry, (char *) beentry, sizeof(PgBackendStatus)); if (save_changecount == beentry->st_changecount && (save_changecount & 1) == 0) break; /* Make sure we can break out of loop if stuck... */ CHECK_FOR_INTERRUPTS(); } beentry++; /* Only valid entries get included into the local array */ if (localentry->st_procpid > 0) { localentry++; localNumBackends++; } } /* Set the pointer only after completion of a valid table */ localBackendStatusTable = localtable; } /* ------------------------------------------------------------ * Local support functions follow * ------------------------------------------------------------ */ /* ---------- * pgstat_setheader() - * * Set common header fields in a statistics message * ---------- */ static void pgstat_setheader(PgStat_MsgHdr *hdr, StatMsgType mtype) { hdr->m_type = mtype; } /* ---------- * pgstat_send() - * * Send out one statistics message to the collector * ---------- */ static void pgstat_send(void *msg, int len) { int rc; if (pgStatSock < 0) return; ((PgStat_MsgHdr *) msg)->m_size = len; /* We'll retry after EINTR, but ignore all other failures */ do { rc = send(pgStatSock, msg, len, 0); } while (rc < 0 && errno == EINTR); #ifdef USE_ASSERT_CHECKING /* In debug builds, log send failures ... */ if (rc < 0) elog(LOG, "could not send to statistics collector: %m"); #endif } /* ---------- * pgstat_send_bgwriter() - * * Send bgwriter statistics to the collector * ---------- */ void pgstat_send_bgwriter(void) { /* * This function can be called even if nothing at all has happened. * In this case, avoid sending a completely empty message to * the stats collector. */ if (BgWriterStats.m_timed_checkpoints == 0 && BgWriterStats.m_requested_checkpoints == 0 && BgWriterStats.m_buf_written_checkpoints == 0 && BgWriterStats.m_buf_written_lru == 0 && BgWriterStats.m_buf_written_all == 0 && BgWriterStats.m_maxwritten_lru == 0 && BgWriterStats.m_maxwritten_all == 0) return; /* * Prepare and send the message */ pgstat_setheader(&BgWriterStats.m_hdr, PGSTAT_MTYPE_BGWRITER); pgstat_send(&BgWriterStats, sizeof(BgWriterStats)); /* * Clear out the bgwriter statistics buffer, so it can be * re-used. */ memset(&BgWriterStats, 0, sizeof(BgWriterStats)); } /* ---------- * PgstatCollectorMain() - * * Start up the statistics collector process. This is the body of the * postmaster child process. * * The argc/argv parameters are valid only in EXEC_BACKEND case. * ---------- */ NON_EXEC_STATIC void PgstatCollectorMain(int argc, char *argv[]) { struct itimerval write_timeout; bool need_timer = false; int len; PgStat_Msg msg; #ifndef WIN32 #ifdef HAVE_POLL struct pollfd input_fd; #else struct timeval sel_timeout; fd_set rfds; #endif #endif IsUnderPostmaster = true; /* we are a postmaster subprocess now */ MyProcPid = getpid(); /* reset MyProcPid */ /* * If possible, make this process a group leader, so that the postmaster * can signal any child processes too. (pgstat probably never has * any child processes, but for consistency we make all postmaster * child processes do this.) */ #ifdef HAVE_SETSID if (setsid() < 0) elog(FATAL, "setsid() failed: %m"); #endif /* * Ignore all signals usually bound to some action in the postmaster, * except SIGQUIT and SIGALRM. */ pqsignal(SIGHUP, SIG_IGN); pqsignal(SIGINT, SIG_IGN); pqsignal(SIGTERM, SIG_IGN); pqsignal(SIGQUIT, pgstat_exit); pqsignal(SIGALRM, force_statwrite); pqsignal(SIGPIPE, SIG_IGN); pqsignal(SIGUSR1, SIG_IGN); pqsignal(SIGUSR2, SIG_IGN); pqsignal(SIGCHLD, SIG_DFL); pqsignal(SIGTTIN, SIG_DFL); pqsignal(SIGTTOU, SIG_DFL); pqsignal(SIGCONT, SIG_DFL); pqsignal(SIGWINCH, SIG_DFL); PG_SETMASK(&UnBlockSig); /* * Identify myself via ps */ init_ps_display("stats collector process", "", "", ""); /* * Arrange to write the initial status file right away */ need_statwrite = true; /* Preset the delay between status file writes */ MemSet(&write_timeout, 0, sizeof(struct itimerval)); write_timeout.it_value.tv_sec = PGSTAT_STAT_INTERVAL / 1000; write_timeout.it_value.tv_usec = (PGSTAT_STAT_INTERVAL % 1000) * 1000; /* * Read in an existing statistics stats file or initialize the stats to * zero. */ pgStatRunningInCollector = true; pgStatDBHash = pgstat_read_statsfile(InvalidOid); /* * Setup the descriptor set for select(2). Since only one bit in the set * ever changes, we need not repeat FD_ZERO each time. */ #if !defined(HAVE_POLL) && !defined(WIN32) FD_ZERO(&rfds); #endif /* * Loop to process messages until we get SIGQUIT or detect ungraceful * death of our parent postmaster. * * For performance reasons, we don't want to do a PostmasterIsAlive() test * after every message; instead, do it at statwrite time and if * select()/poll() is interrupted by timeout. */ for (;;) { int got_data; /* * Quit if we get SIGQUIT from the postmaster. */ if (need_exit) break; /* * If time to write the stats file, do so. Note that the alarm * interrupt isn't re-enabled immediately, but only after we next * receive a stats message; so no cycles are wasted when there is * nothing going on. */ if (need_statwrite) { /* Check for postmaster death; if so we'll write file below */ if (!PostmasterIsAlive(true)) break; pgstat_write_statsfile(); need_statwrite = false; need_timer = true; } /* * Wait for a message to arrive; but not for more than * PGSTAT_SELECT_TIMEOUT seconds. (This determines how quickly we will * shut down after an ungraceful postmaster termination; so it needn't * be very fast. However, on some systems SIGQUIT won't interrupt the * poll/select call, so this also limits speed of response to SIGQUIT, * which is more important.) * * We use poll(2) if available, otherwise select(2). * Win32 has its own implementation. */ #ifndef WIN32 #ifdef HAVE_POLL input_fd.fd = pgStatSock; input_fd.events = POLLIN | POLLERR; input_fd.revents = 0; if (poll(&input_fd, 1, PGSTAT_SELECT_TIMEOUT * 1000) < 0) { if (errno == EINTR) continue; ereport(ERROR, (errcode_for_socket_access(), errmsg("poll() failed in statistics collector: %m"))); } got_data = (input_fd.revents != 0); #else /* !HAVE_POLL */ FD_SET(pgStatSock, &rfds); /* * timeout struct is modified by select() on some operating systems, * so re-fill it each time. */ sel_timeout.tv_sec = PGSTAT_SELECT_TIMEOUT; sel_timeout.tv_usec = 0; if (select(pgStatSock + 1, &rfds, NULL, NULL, &sel_timeout) < 0) { if (errno == EINTR) continue; ereport(ERROR, (errcode_for_socket_access(), errmsg("select() failed in statistics collector: %m"))); } got_data = FD_ISSET(pgStatSock, &rfds); #endif /* HAVE_POLL */ #else /* WIN32 */ got_data = pgwin32_waitforsinglesocket(pgStatSock, FD_READ, PGSTAT_SELECT_TIMEOUT*1000); #endif /* * If there is a message on the socket, read it and check for * validity. */ if (got_data) { len = recv(pgStatSock, (char *) &msg, sizeof(PgStat_Msg), 0); if (len < 0) { if (errno == EINTR) continue; ereport(ERROR, (errcode_for_socket_access(), errmsg("could not read statistics message: %m"))); } /* * We ignore messages that are smaller than our common header */ if (len < sizeof(PgStat_MsgHdr)) continue; /* * The received length must match the length in the header */ if (msg.msg_hdr.m_size != len) continue; /* * O.K. - we accept this message. Process it. */ switch (msg.msg_hdr.m_type) { case PGSTAT_MTYPE_DUMMY: break; case PGSTAT_MTYPE_TABSTAT: pgstat_recv_tabstat((PgStat_MsgTabstat *) &msg, len); break; case PGSTAT_MTYPE_TABPURGE: pgstat_recv_tabpurge((PgStat_MsgTabpurge *) &msg, len); break; case PGSTAT_MTYPE_DROPDB: pgstat_recv_dropdb((PgStat_MsgDropdb *) &msg, len); break; case PGSTAT_MTYPE_RESETCOUNTER: pgstat_recv_resetcounter((PgStat_MsgResetcounter *) &msg, len); break; case PGSTAT_MTYPE_AUTOVAC_START: pgstat_recv_autovac((PgStat_MsgAutovacStart *) &msg, len); break; case PGSTAT_MTYPE_VACUUM: pgstat_recv_vacuum((PgStat_MsgVacuum *) &msg, len); break; case PGSTAT_MTYPE_ANALYZE: pgstat_recv_analyze((PgStat_MsgAnalyze *) &msg, len); break; case PGSTAT_MTYPE_BGWRITER: pgstat_recv_bgwriter((PgStat_MsgBgWriter *) &msg, len); break; default: break; } /* * If this is the first message after we wrote the stats file the * last time, enable the alarm interrupt to make it be written * again later. */ if (need_timer) { if (setitimer(ITIMER_REAL, &write_timeout, NULL)) ereport(ERROR, (errmsg("could not set statistics collector timer: %m"))); need_timer = false; } } else { /* * We can only get here if the select/poll timeout elapsed. Check * for postmaster death. */ if (!PostmasterIsAlive(true)) break; } } /* end of message-processing loop */ /* * Save the final stats to reuse at next startup. */ pgstat_write_statsfile(); exit(0); } /* SIGQUIT signal handler for collector process */ static void pgstat_exit(SIGNAL_ARGS) { need_exit = true; } /* SIGALRM signal handler for collector process */ static void force_statwrite(SIGNAL_ARGS) { need_statwrite = true; } /* * Lookup the hash table entry for the specified database. If no hash * table entry exists, initialize it, if the create parameter is true. * Else, return NULL. */ static PgStat_StatDBEntry * pgstat_get_db_entry(Oid databaseid, bool create) { PgStat_StatDBEntry *result; bool found; HASHACTION action = (create ? HASH_ENTER : HASH_FIND); /* Lookup or create the hash table entry for this database */ result = (PgStat_StatDBEntry *) hash_search(pgStatDBHash, &databaseid, action, &found); if (!create && !found) return NULL; /* If not found, initialize the new one. */ if (!found) { HASHCTL hash_ctl; result->tables = NULL; result->n_xact_commit = 0; result->n_xact_rollback = 0; result->n_blocks_fetched = 0; result->n_blocks_hit = 0; result->n_tuples_returned = 0; result->n_tuples_fetched = 0; result->n_tuples_inserted = 0; result->n_tuples_updated = 0; result->n_tuples_deleted = 0; result->last_autovac_time = 0; memset(&hash_ctl, 0, sizeof(hash_ctl)); hash_ctl.keysize = sizeof(Oid); hash_ctl.entrysize = sizeof(PgStat_StatTabEntry); hash_ctl.hash = oid_hash; result->tables = hash_create("Per-database table", PGSTAT_TAB_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_FUNCTION); } return result; } /* ---------- * pgstat_write_statsfile() - * * Tell the news. * ---------- */ static void pgstat_write_statsfile(void) { HASH_SEQ_STATUS hstat; HASH_SEQ_STATUS tstat; PgStat_StatDBEntry *dbentry; PgStat_StatTabEntry *tabentry; FILE *fpout; int32 format_id; /* * Open the statistics temp file to write out the current values. */ fpout = fopen(PGSTAT_STAT_TMPFILE, PG_BINARY_W); if (fpout == NULL) { ereport(LOG, (errcode_for_file_access(), errmsg("could not open temporary statistics file \"%s\": %m", PGSTAT_STAT_TMPFILE))); return; } /* * Write the file header --- currently just a format ID. */ format_id = PGSTAT_FILE_FORMAT_ID; fwrite(&format_id, sizeof(format_id), 1, fpout); /* * Write global stats struct */ fwrite(&globalStats, sizeof(globalStats), 1, fpout); /* * Walk through the database table. */ hash_seq_init(&hstat, pgStatDBHash); while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL) { /* * Write out the DB entry including the number of live backends. We * don't write the tables pointer since it's of no use to any other * process. */ fputc('D', fpout); fwrite(dbentry, offsetof(PgStat_StatDBEntry, tables), 1, fpout); /* * Walk through the database's access stats per table. */ hash_seq_init(&tstat, dbentry->tables); while ((tabentry = (PgStat_StatTabEntry *) hash_seq_search(&tstat)) != NULL) { fputc('T', fpout); fwrite(tabentry, sizeof(PgStat_StatTabEntry), 1, fpout); } /* * Mark the end of this DB */ fputc('d', fpout); } /* * No more output to be done. Close the temp file and replace the old * pgstat.stat with it. The ferror() check replaces testing for error * after each individual fputc or fwrite above. */ fputc('E', fpout); if (ferror(fpout)) { ereport(LOG, (errcode_for_file_access(), errmsg("could not write temporary statistics file \"%s\": %m", PGSTAT_STAT_TMPFILE))); fclose(fpout); unlink(PGSTAT_STAT_TMPFILE); } else if (fclose(fpout) < 0) { ereport(LOG, (errcode_for_file_access(), errmsg("could not close temporary statistics file \"%s\": %m", PGSTAT_STAT_TMPFILE))); unlink(PGSTAT_STAT_TMPFILE); } else if (rename(PGSTAT_STAT_TMPFILE, PGSTAT_STAT_FILENAME) < 0) { ereport(LOG, (errcode_for_file_access(), errmsg("could not rename temporary statistics file \"%s\" to \"%s\": %m", PGSTAT_STAT_TMPFILE, PGSTAT_STAT_FILENAME))); unlink(PGSTAT_STAT_TMPFILE); } } /* ---------- * pgstat_read_statsfile() - * * Reads in an existing statistics collector file and initializes the * databases' hash table (whose entries point to the tables' hash tables). * ---------- */ static HTAB * pgstat_read_statsfile(Oid onlydb) { PgStat_StatDBEntry *dbentry; PgStat_StatDBEntry dbbuf; PgStat_StatTabEntry *tabentry; PgStat_StatTabEntry tabbuf; HASHCTL hash_ctl; HTAB *dbhash; HTAB *tabhash = NULL; FILE *fpin; int32 format_id; bool found; /* * The tables will live in pgStatLocalContext. */ pgstat_setup_memcxt(); /* * Create the DB hashtable */ memset(&hash_ctl, 0, sizeof(hash_ctl)); hash_ctl.keysize = sizeof(Oid); hash_ctl.entrysize = sizeof(PgStat_StatDBEntry); hash_ctl.hash = oid_hash; hash_ctl.hcxt = pgStatLocalContext; dbhash = hash_create("Databases hash", PGSTAT_DB_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_FUNCTION | HASH_CONTEXT); /* * Clear out global statistics so they start from zero in case we can't * load an existing statsfile. */ memset(&globalStats, 0, sizeof(globalStats)); /* * Try to open the status file. If it doesn't exist, the backends simply * return zero for anything and the collector simply starts from scratch * with empty counters. */ if ((fpin = AllocateFile(PGSTAT_STAT_FILENAME, PG_BINARY_R)) == NULL) return dbhash; /* * Verify it's of the expected format. */ if (fread(&format_id, 1, sizeof(format_id), fpin) != sizeof(format_id) || format_id != PGSTAT_FILE_FORMAT_ID) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted pgstat.stat file"))); goto done; } /* * Read global stats struct */ if (fread(&globalStats, 1, sizeof(globalStats), fpin) != sizeof(globalStats)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted pgstat.stat file"))); goto done; } /* * We found an existing collector stats file. Read it and put all the * hashtable entries into place. */ for (;;) { switch (fgetc(fpin)) { /* * 'D' A PgStat_StatDBEntry struct describing a database * follows. Subsequently, zero to many 'T' entries will follow * until a 'd' is encountered. */ case 'D': if (fread(&dbbuf, 1, offsetof(PgStat_StatDBEntry, tables), fpin) != offsetof(PgStat_StatDBEntry, tables)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted pgstat.stat file"))); goto done; } /* * Add to the DB hash */ dbentry = (PgStat_StatDBEntry *) hash_search(dbhash, (void *) &dbbuf.databaseid, HASH_ENTER, &found); if (found) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted pgstat.stat file"))); goto done; } memcpy(dbentry, &dbbuf, sizeof(PgStat_StatDBEntry)); dbentry->tables = NULL; /* * Don't collect tables if not the requested DB (or the * shared-table info) */ if (onlydb != InvalidOid) { if (dbbuf.databaseid != onlydb && dbbuf.databaseid != InvalidOid) break; } memset(&hash_ctl, 0, sizeof(hash_ctl)); hash_ctl.keysize = sizeof(Oid); hash_ctl.entrysize = sizeof(PgStat_StatTabEntry); hash_ctl.hash = oid_hash; hash_ctl.hcxt = pgStatLocalContext; dbentry->tables = hash_create("Per-database table", PGSTAT_TAB_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_FUNCTION | HASH_CONTEXT); /* * Arrange that following 'T's add entries to this database's * tables hash table. */ tabhash = dbentry->tables; break; /* * 'd' End of this database. */ case 'd': tabhash = NULL; break; /* * 'T' A PgStat_StatTabEntry follows. */ case 'T': if (fread(&tabbuf, 1, sizeof(PgStat_StatTabEntry), fpin) != sizeof(PgStat_StatTabEntry)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted pgstat.stat file"))); goto done; } /* * Skip if table belongs to a not requested database. */ if (tabhash == NULL) break; tabentry = (PgStat_StatTabEntry *) hash_search(tabhash, (void *) &tabbuf.tableid, HASH_ENTER, &found); if (found) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted pgstat.stat file"))); goto done; } memcpy(tabentry, &tabbuf, sizeof(tabbuf)); break; /* * 'E' The EOF marker of a complete stats file. */ case 'E': goto done; default: ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted pgstat.stat file"))); goto done; } } done: FreeFile(fpin); return dbhash; } /* * If not already done, read the statistics collector stats file into * some hash tables. The results will be kept until pgstat_clear_snapshot() * is called (typically, at end of transaction). */ static void backend_read_statsfile(void) { /* already read it? */ if (pgStatDBHash) return; Assert(!pgStatRunningInCollector); /* Autovacuum launcher wants stats about all databases */ if (IsAutoVacuumLauncherProcess()) pgStatDBHash = pgstat_read_statsfile(InvalidOid); else pgStatDBHash = pgstat_read_statsfile(MyDatabaseId); } /* ---------- * pgstat_setup_memcxt() - * * Create pgStatLocalContext, if not already done. * ---------- */ static void pgstat_setup_memcxt(void) { if (!pgStatLocalContext) pgStatLocalContext = AllocSetContextCreate(TopMemoryContext, "Statistics snapshot", ALLOCSET_SMALL_MINSIZE, ALLOCSET_SMALL_INITSIZE, ALLOCSET_SMALL_MAXSIZE); } /* ---------- * pgstat_clear_snapshot() - * * Discard any data collected in the current transaction. Any subsequent * request will cause new snapshots to be read. * * This is also invoked during transaction commit or abort to discard * the no-longer-wanted snapshot. * ---------- */ void pgstat_clear_snapshot(void) { /* Release memory, if any was allocated */ if (pgStatLocalContext) MemoryContextDelete(pgStatLocalContext); /* Reset variables */ pgStatLocalContext = NULL; pgStatDBHash = NULL; localBackendStatusTable = NULL; localNumBackends = 0; } /* ---------- * pgstat_recv_tabstat() - * * Count what the backend has done. * ---------- */ static void pgstat_recv_tabstat(PgStat_MsgTabstat *msg, int len) { PgStat_TableEntry *tabmsg = &(msg->m_entry[0]); PgStat_StatDBEntry *dbentry; PgStat_StatTabEntry *tabentry; int i; bool found; dbentry = pgstat_get_db_entry(msg->m_databaseid, true); /* * Update database-wide stats. */ dbentry->n_xact_commit += (PgStat_Counter) (msg->m_xact_commit); dbentry->n_xact_rollback += (PgStat_Counter) (msg->m_xact_rollback); /* * Process all table entries in the message. */ for (i = 0; i < msg->m_nentries; i++) { tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables, (void *) &(tabmsg[i].t_id), HASH_ENTER, &found); if (!found) { /* * If it's a new table entry, initialize counters to the values we * just got. */ tabentry->numscans = tabmsg[i].t_numscans; tabentry->tuples_returned = tabmsg[i].t_tuples_returned; tabentry->tuples_fetched = tabmsg[i].t_tuples_fetched; tabentry->tuples_inserted = tabmsg[i].t_tuples_inserted; tabentry->tuples_updated = tabmsg[i].t_tuples_updated; tabentry->tuples_deleted = tabmsg[i].t_tuples_deleted; tabentry->n_live_tuples = tabmsg[i].t_tuples_inserted; tabentry->n_dead_tuples = tabmsg[i].t_tuples_updated + tabmsg[i].t_tuples_deleted; tabentry->last_anl_tuples = 0; tabentry->vacuum_timestamp = 0; tabentry->autovac_vacuum_timestamp = 0; tabentry->analyze_timestamp = 0; tabentry->autovac_analyze_timestamp = 0; tabentry->blocks_fetched = tabmsg[i].t_blocks_fetched; tabentry->blocks_hit = tabmsg[i].t_blocks_hit; } else { /* * Otherwise add the values to the existing entry. */ tabentry->numscans += tabmsg[i].t_numscans; tabentry->tuples_returned += tabmsg[i].t_tuples_returned; tabentry->tuples_fetched += tabmsg[i].t_tuples_fetched; tabentry->tuples_inserted += tabmsg[i].t_tuples_inserted; tabentry->tuples_updated += tabmsg[i].t_tuples_updated; tabentry->tuples_deleted += tabmsg[i].t_tuples_deleted; tabentry->n_live_tuples += tabmsg[i].t_tuples_inserted - tabmsg[i].t_tuples_deleted; tabentry->n_dead_tuples += tabmsg[i].t_tuples_updated + tabmsg[i].t_tuples_deleted; tabentry->blocks_fetched += tabmsg[i].t_blocks_fetched; tabentry->blocks_hit += tabmsg[i].t_blocks_hit; } /* * Add table stats to the database entry. */ dbentry->n_tuples_returned += tabmsg[i].t_tuples_returned; dbentry->n_tuples_fetched += tabmsg[i].t_tuples_fetched; dbentry->n_tuples_inserted += tabmsg[i].t_tuples_inserted; dbentry->n_tuples_updated += tabmsg[i].t_tuples_updated; dbentry->n_tuples_deleted += tabmsg[i].t_tuples_deleted; /* * And add the block IO to the database entry. */ dbentry->n_blocks_fetched += tabmsg[i].t_blocks_fetched; dbentry->n_blocks_hit += tabmsg[i].t_blocks_hit; } } /* ---------- * pgstat_recv_tabpurge() - * * Arrange for dead table removal. * ---------- */ static void pgstat_recv_tabpurge(PgStat_MsgTabpurge *msg, int len) { PgStat_StatDBEntry *dbentry; int i; dbentry = pgstat_get_db_entry(msg->m_databaseid, false); /* * No need to purge if we don't even know the database. */ if (!dbentry || !dbentry->tables) return; /* * Process all table entries in the message. */ for (i = 0; i < msg->m_nentries; i++) { /* Remove from hashtable if present; we don't care if it's not. */ (void) hash_search(dbentry->tables, (void *) &(msg->m_tableid[i]), HASH_REMOVE, NULL); } } /* ---------- * pgstat_recv_dropdb() - * * Arrange for dead database removal * ---------- */ static void pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len) { PgStat_StatDBEntry *dbentry; /* * Lookup the database in the hashtable. */ dbentry = pgstat_get_db_entry(msg->m_databaseid, false); /* * If found, remove it. */ if (dbentry) { if (dbentry->tables != NULL) hash_destroy(dbentry->tables); if (hash_search(pgStatDBHash, (void *) &(dbentry->databaseid), HASH_REMOVE, NULL) == NULL) ereport(ERROR, (errmsg("database hash table corrupted " "during cleanup --- abort"))); } } /* ---------- * pgstat_recv_resetcounter() - * * Reset the statistics for the specified database. * ---------- */ static void pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len) { HASHCTL hash_ctl; PgStat_StatDBEntry *dbentry; /* * Lookup the database in the hashtable. Nothing to do if not there. */ dbentry = pgstat_get_db_entry(msg->m_databaseid, false); if (!dbentry) return; /* * We simply throw away all the database's table entries by recreating a * new hash table for them. */ if (dbentry->tables != NULL) hash_destroy(dbentry->tables); dbentry->tables = NULL; dbentry->n_xact_commit = 0; dbentry->n_xact_rollback = 0; dbentry->n_blocks_fetched = 0; dbentry->n_blocks_hit = 0; memset(&hash_ctl, 0, sizeof(hash_ctl)); hash_ctl.keysize = sizeof(Oid); hash_ctl.entrysize = sizeof(PgStat_StatTabEntry); hash_ctl.hash = oid_hash; dbentry->tables = hash_create("Per-database table", PGSTAT_TAB_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_FUNCTION); } /* ---------- * pgstat_recv_autovac() - * * Process an autovacuum signalling message. * ---------- */ static void pgstat_recv_autovac(PgStat_MsgAutovacStart *msg, int len) { PgStat_StatDBEntry *dbentry; /* * Lookup the database in the hashtable. Don't create the entry if it * doesn't exist, because autovacuum may be processing a template * database. If this isn't the case, the database is most likely to have * an entry already. (If it doesn't, not much harm is done anyway -- * it'll get created as soon as somebody actually uses the database.) */ dbentry = pgstat_get_db_entry(msg->m_databaseid, false); if (dbentry == NULL) return; /* * Store the last autovacuum time in the database entry. */ dbentry->last_autovac_time = msg->m_start_time; } /* ---------- * pgstat_recv_vacuum() - * * Process a VACUUM message. * ---------- */ static void pgstat_recv_vacuum(PgStat_MsgVacuum *msg, int len) { PgStat_StatDBEntry *dbentry; PgStat_StatTabEntry *tabentry; /* * Don't create either the database or table entry if it doesn't already * exist. This avoids bloating the stats with entries for stuff that is * only touched by vacuum and not by live operations. */ dbentry = pgstat_get_db_entry(msg->m_databaseid, false); if (dbentry == NULL) return; tabentry = hash_search(dbentry->tables, &(msg->m_tableoid), HASH_FIND, NULL); if (tabentry == NULL) return; if (msg->m_autovacuum) tabentry->autovac_vacuum_timestamp = msg->m_vacuumtime; else tabentry->vacuum_timestamp = msg->m_vacuumtime; tabentry->n_live_tuples = msg->m_tuples; tabentry->n_dead_tuples = 0; if (msg->m_analyze) { tabentry->last_anl_tuples = msg->m_tuples; if (msg->m_autovacuum) tabentry->autovac_analyze_timestamp = msg->m_vacuumtime; else tabentry->analyze_timestamp = msg->m_vacuumtime; } else { /* last_anl_tuples must never exceed n_live_tuples */ tabentry->last_anl_tuples = Min(tabentry->last_anl_tuples, msg->m_tuples); } } /* ---------- * pgstat_recv_analyze() - * * Process an ANALYZE message. * ---------- */ static void pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len) { PgStat_StatDBEntry *dbentry; PgStat_StatTabEntry *tabentry; /* * Don't create either the database or table entry if it doesn't already * exist. This avoids bloating the stats with entries for stuff that is * only touched by analyze and not by live operations. */ dbentry = pgstat_get_db_entry(msg->m_databaseid, false); if (dbentry == NULL) return; tabentry = hash_search(dbentry->tables, &(msg->m_tableoid), HASH_FIND, NULL); if (tabentry == NULL) return; if (msg->m_autovacuum) tabentry->autovac_analyze_timestamp = msg->m_analyzetime; else tabentry->analyze_timestamp = msg->m_analyzetime; tabentry->n_live_tuples = msg->m_live_tuples; tabentry->n_dead_tuples = msg->m_dead_tuples; tabentry->last_anl_tuples = msg->m_live_tuples + msg->m_dead_tuples; } /* ---------- * pgstat_recv_bgwriter() - * * Process a BGWRITER message. * ---------- */ static void pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len) { globalStats.timed_checkpoints += msg->m_timed_checkpoints; globalStats.requested_checkpoints += msg->m_requested_checkpoints; globalStats.buf_written_checkpoints += msg->m_buf_written_checkpoints; globalStats.buf_written_lru += msg->m_buf_written_lru; globalStats.buf_written_all += msg->m_buf_written_all; globalStats.maxwritten_lru += msg->m_maxwritten_lru; globalStats.maxwritten_all += msg->m_maxwritten_all; }