/* ---------- * 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) 2001-2022, PostgreSQL Global Development Group * * src/backend/postmaster/pgstat.c * ---------- */ #include "postgres.h" #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_SYS_SELECT_H #include #endif #include "access/heapam.h" #include "access/htup_details.h" #include "access/tableam.h" #include "access/transam.h" #include "access/xact.h" #include "catalog/catalog.h" #include "catalog/pg_database.h" #include "catalog/pg_proc.h" #include "catalog/pg_subscription.h" #include "common/ip.h" #include "libpq/libpq.h" #include "libpq/pqsignal.h" #include "mb/pg_wchar.h" #include "miscadmin.h" #include "pgstat.h" #include "postmaster/autovacuum.h" #include "postmaster/fork_process.h" #include "postmaster/interrupt.h" #include "postmaster/postmaster.h" #include "replication/slot.h" #include "replication/walsender.h" #include "storage/backendid.h" #include "storage/dsm.h" #include "storage/fd.h" #include "storage/ipc.h" #include "storage/latch.h" #include "storage/lmgr.h" #include "storage/pg_shmem.h" #include "storage/proc.h" #include "storage/procsignal.h" #include "utils/builtins.h" #include "utils/guc.h" #include "utils/memutils.h" #include "utils/pgstat_internal.h" #include "utils/ps_status.h" #include "utils/rel.h" #include "utils/snapmgr.h" #include "utils/timestamp.h" /* ---------- * Timer definitions. * ---------- */ #define PGSTAT_RETRY_DELAY 10 /* How long to wait between checks for a * new file; in milliseconds. */ #define PGSTAT_MAX_WAIT_TIME 10000 /* Maximum time to wait for a stats * file update; in milliseconds. */ #define PGSTAT_INQ_INTERVAL 640 /* How often to ping the collector for a * new file; in milliseconds. */ #define PGSTAT_RESTART_INTERVAL 60 /* How often to attempt to restart a * failed statistics collector; in * seconds. */ #define PGSTAT_POLL_LOOP_COUNT (PGSTAT_MAX_WAIT_TIME / PGSTAT_RETRY_DELAY) #define PGSTAT_INQ_LOOP_COUNT (PGSTAT_INQ_INTERVAL / PGSTAT_RETRY_DELAY) /* Minimum receive buffer size for the collector's socket. */ #define PGSTAT_MIN_RCVBUF (100 * 1024) /* ---------- * GUC parameters * ---------- */ bool pgstat_track_counts = false; /* ---------- * Built from GUC parameter * ---------- */ char *pgstat_stat_directory = NULL; char *pgstat_stat_filename = NULL; char *pgstat_stat_tmpname = NULL; /* ---------- * state shared with pgstat_*.c * ---------- */ pgsocket pgStatSock = PGINVALID_SOCKET; /* ---------- * Local data * ---------- */ static struct sockaddr_storage pgStatAddr; static time_t last_pgstat_start_time; static bool pgStatRunningInCollector = false; static PgStat_SubXactStatus *pgStatXactStack = NULL; /* * Info about current "snapshot" of stats file */ static MemoryContext pgStatLocalContext = NULL; static HTAB *pgStatDBHash = NULL; /* * Cluster wide statistics, kept in the stats collector. * Contains statistics that are not collected per database * or per table. */ static PgStat_ArchiverStats archiverStats; static PgStat_GlobalStats globalStats; static PgStat_WalStats walStats; static PgStat_SLRUStats slruStats[SLRU_NUM_ELEMENTS]; static HTAB *replSlotStatHash = NULL; static HTAB *subscriptionStatHash = NULL; /* * List of OIDs of databases we need to write out. If an entry is InvalidOid, * it means to write only the shared-catalog stats ("DB 0"); otherwise, we * will write both that DB's data and the shared stats. */ static List *pending_write_requests = NIL; /* * For assertions that check pgstat is not used before initialization / after * shutdown. */ #ifdef USE_ASSERT_CHECKING static bool pgstat_is_initialized = false; static bool pgstat_is_shutdown = false; #endif /* ---------- * Local function forward declarations * ---------- */ #ifdef EXEC_BACKEND static pid_t pgstat_forkexec(void); #endif NON_EXEC_STATIC void PgstatCollectorMain(int argc, char *argv[]) pg_attribute_noreturn(); static PgStat_StatDBEntry *pgstat_get_db_entry(Oid databaseid, bool create); static PgStat_StatTabEntry *pgstat_get_tab_entry(PgStat_StatDBEntry *dbentry, Oid tableoid, bool create); static PgStat_StatSubEntry *pgstat_get_subscription_entry(Oid subid, bool create); static void pgstat_reset_subscription(PgStat_StatSubEntry *subentry, TimestampTz ts); static void pgstat_write_statsfiles(bool permanent, bool allDbs); static void pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent); static HTAB *pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep); static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, bool permanent); static void backend_read_statsfile(void); static bool pgstat_write_statsfile_needed(void); static bool pgstat_db_requested(Oid databaseid); static PgStat_StatReplSlotEntry *pgstat_get_replslot_entry(NameData name, bool create_it); static void pgstat_reset_replslot(PgStat_StatReplSlotEntry *slotstats, TimestampTz ts); static HTAB *pgstat_collect_oids(Oid catalogid, AttrNumber anum_oid); static void pgstat_setup_memcxt(void); static void pgstat_recv_inquiry(PgStat_MsgInquiry *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_resetsharedcounter(PgStat_MsgResetsharedcounter *msg, int len); static void pgstat_recv_resetsinglecounter(PgStat_MsgResetsinglecounter *msg, int len); static void pgstat_recv_resetslrucounter(PgStat_MsgResetslrucounter *msg, int len); static void pgstat_recv_resetreplslotcounter(PgStat_MsgResetreplslotcounter *msg, int len); static void pgstat_recv_resetsubcounter(PgStat_MsgResetsubcounter *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_archiver(PgStat_MsgArchiver *msg, int len); static void pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len); static void pgstat_recv_checkpointer(PgStat_MsgCheckpointer *msg, int len); static void pgstat_recv_wal(PgStat_MsgWal *msg, int len); static void pgstat_recv_slru(PgStat_MsgSLRU *msg, int len); static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len); static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len); static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len); static void pgstat_recv_deadlock(PgStat_MsgDeadlock *msg, int len); static void pgstat_recv_checksum_failure(PgStat_MsgChecksumFailure *msg, int len); static void pgstat_recv_connect(PgStat_MsgConnect *msg, int len); static void pgstat_recv_disconnect(PgStat_MsgDisconnect *msg, int len); static void pgstat_recv_replslot(PgStat_MsgReplSlot *msg, int len); static void pgstat_recv_tempfile(PgStat_MsgTempFile *msg, int len); static void pgstat_recv_subscription_drop(PgStat_MsgSubscriptionDrop *msg, int len); static void pgstat_recv_subscription_error(PgStat_MsgSubscriptionError *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) { socklen_t 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) /* * This static assertion verifies that we didn't mess up the calculations * involved in selecting maximum payload sizes for our UDP messages. * Because the only consequence of overrunning PGSTAT_MAX_MSG_SIZE would * be silent performance loss from fragmentation, it seems worth having a * compile-time cross-check that we didn't. */ StaticAssertStmt(sizeof(PgStat_Msg) <= PGSTAT_MAX_MSG_SIZE, "maximum stats message size exceeds PGSTAT_MAX_MSG_SIZE"); /* * Create the UDP socket for sending and receiving statistic messages */ hints.ai_flags = AI_PASSIVE; hints.ai_family = AF_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)) == PGINVALID_SOCKET) { 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 = PGINVALID_SOCKET; 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 = PGINVALID_SOCKET; 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 = PGINVALID_SOCKET; 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 = PGINVALID_SOCKET; 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 = PGINVALID_SOCKET; 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 = PGINVALID_SOCKET; 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 = PGINVALID_SOCKET; 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 = PGINVALID_SOCKET; continue; } /* If we get here, we have a working socket */ break; } /* Did we find a working address? */ if (!addr || pgStatSock == PGINVALID_SOCKET) 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; } /* * Try to ensure that the socket's receive buffer is at least * PGSTAT_MIN_RCVBUF bytes, so that it won't easily overflow and lose * data. Use of UDP protocol means that we are willing to lose data under * heavy load, but we don't want it to happen just because of ridiculously * small default buffer sizes (such as 8KB on older Windows versions). */ { int old_rcvbuf; int new_rcvbuf; socklen_t rcvbufsize = sizeof(old_rcvbuf); if (getsockopt(pgStatSock, SOL_SOCKET, SO_RCVBUF, (char *) &old_rcvbuf, &rcvbufsize) < 0) { ereport(LOG, (errmsg("%s(%s) failed: %m", "getsockopt", "SO_RCVBUF"))); /* if we can't get existing size, always try to set it */ old_rcvbuf = 0; } new_rcvbuf = PGSTAT_MIN_RCVBUF; if (old_rcvbuf < new_rcvbuf) { if (setsockopt(pgStatSock, SOL_SOCKET, SO_RCVBUF, (char *) &new_rcvbuf, sizeof(new_rcvbuf)) < 0) ereport(LOG, (errmsg("%s(%s) failed: %m", "setsockopt", "SO_RCVBUF"))); } } pg_freeaddrinfo_all(hints.ai_family, addrs); /* Now that we have a long-lived socket, tell fd.c about it. */ ReserveExternalFD(); 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 != PGINVALID_SOCKET) closesocket(pgStatSock); pgStatSock = PGINVALID_SOCKET; /* * Adjust GUC variables to suppress useless activity, and for debugging * purposes (seeing track_counts off is a clue that we failed here). We * use PGC_S_OVERRIDE because there is no point in trying to turn it back * on from postgresql.conf without a restart. */ SetConfigOption("track_counts", "off", PGC_INTERNAL, PGC_S_OVERRIDE); } /* * subroutine for pgstat_reset_all */ static void pgstat_reset_remove_files(const char *directory) { DIR *dir; struct dirent *entry; char fname[MAXPGPATH * 2]; dir = AllocateDir(directory); while ((entry = ReadDir(dir, directory)) != NULL) { int nchars; Oid tmp_oid; /* * Skip directory entries that don't match the file names we write. * See get_dbstat_filename for the database-specific pattern. */ if (strncmp(entry->d_name, "global.", 7) == 0) nchars = 7; else { nchars = 0; (void) sscanf(entry->d_name, "db_%u.%n", &tmp_oid, &nchars); if (nchars <= 0) continue; /* %u allows leading whitespace, so reject that */ if (strchr("0123456789", entry->d_name[3]) == NULL) continue; } if (strcmp(entry->d_name + nchars, "tmp") != 0 && strcmp(entry->d_name + nchars, "stat") != 0) continue; snprintf(fname, sizeof(fname), "%s/%s", directory, entry->d_name); unlink(fname); } FreeDir(dir); } /* * pgstat_reset_all() - * * Remove the stats files. This is currently used only if WAL * recovery is needed after a crash. */ void pgstat_reset_all(void) { pgstat_reset_remove_files(pgstat_stat_directory); pgstat_reset_remove_files(PGSTAT_STAT_PERMANENT_DIRECTORY); } #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; /* * Check that the socket is there, else pgstat_init failed and we can do * nothing useful. */ if (pgStatSock == PGINVALID_SOCKET) 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; /* * 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 ... */ InitPostmasterChild(); /* Close the postmaster's sockets */ ClosePostmasterPorts(false); /* Drop our connection to postmaster's shared memory, as well */ dsm_detach_all(); 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_stat() - * * Must be called by processes that performs DML: tcop/postgres.c, logical * receiver processes, SPI worker, etc. to send the so far collected * per-table and function usage 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. * * "disconnect" is "true" only for the last call before the backend * exits. This makes sure that no data is lost and that interrupted * sessions are reported correctly. * ---------- */ void pgstat_report_stat(bool disconnect) { static TimestampTz last_report = 0; TimestampTz now; pgstat_assert_is_up(); /* * Don't expend a clock check if nothing to do. */ if (!have_relation_stats && pgStatXactCommit == 0 && pgStatXactRollback == 0 && !pgstat_wal_pending() && !have_function_stats && !disconnect) return; /* * Don't send a message unless it's been at least PGSTAT_STAT_INTERVAL * msec since we last sent one, or the backend is about to exit. */ now = GetCurrentTransactionStopTimestamp(); if (!disconnect && !TimestampDifferenceExceeds(last_report, now, PGSTAT_STAT_INTERVAL)) return; last_report = now; if (disconnect) pgstat_report_disconnect(MyDatabaseId); /* First, send relation statistics */ pgstat_send_tabstats(now, disconnect); /* Now, send function statistics */ pgstat_send_funcstats(); /* Send WAL statistics */ pgstat_send_wal(true); /* Finally send SLRU statistics */ pgstat_send_slru(); } /* ---------- * pgstat_vacuum_stat() - * * Will tell the collector about objects he can get rid of. * ---------- */ void pgstat_vacuum_stat(void) { HTAB *htab; PgStat_MsgTabpurge msg; PgStat_MsgFuncpurge f_msg; HASH_SEQ_STATUS hstat; PgStat_StatDBEntry *dbentry; PgStat_StatTabEntry *tabentry; PgStat_StatFuncEntry *funcentry; int len; if (pgStatSock == PGINVALID_SOCKET) 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, Anum_pg_database_oid); /* * 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(); /* the DB entry for shared tables (with InvalidOid) is never dropped */ if (OidIsValid(dbid) && hash_search(htab, (void *) &dbid, HASH_FIND, NULL) == NULL) pgstat_drop_database(dbid); } /* Clean up */ hash_destroy(htab); /* * Search for all the dead replication slots in stats hashtable and tell * the stats collector to drop them. */ if (replSlotStatHash) { PgStat_StatReplSlotEntry *slotentry; hash_seq_init(&hstat, replSlotStatHash); while ((slotentry = (PgStat_StatReplSlotEntry *) hash_seq_search(&hstat)) != NULL) { CHECK_FOR_INTERRUPTS(); if (SearchNamedReplicationSlot(NameStr(slotentry->slotname), true) == NULL) pgstat_report_replslot_drop(NameStr(slotentry->slotname)); } } /* * Repeat the above steps for subscriptions, if subscription stats are * being collected. */ if (subscriptionStatHash) { PgStat_StatSubEntry *subentry; /* * Read pg_subscription and make a list of OIDs of all existing * subscriptions. */ htab = pgstat_collect_oids(SubscriptionRelationId, Anum_pg_subscription_oid); hash_seq_init(&hstat, subscriptionStatHash); while ((subentry = (PgStat_StatSubEntry *) hash_seq_search(&hstat)) != NULL) { CHECK_FOR_INTERRUPTS(); if (hash_search(htab, (void *) &(subentry->subid), HASH_FIND, NULL) == NULL) pgstat_report_subscription_drop(subentry->subid); } 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, Anum_pg_class_oid); /* * 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); /* * Now repeat the above steps for functions. However, we needn't bother * in the common case where no function stats are being collected. */ if (dbentry->functions != NULL && hash_get_num_entries(dbentry->functions) > 0) { htab = pgstat_collect_oids(ProcedureRelationId, Anum_pg_proc_oid); pgstat_setheader(&f_msg.m_hdr, PGSTAT_MTYPE_FUNCPURGE); f_msg.m_databaseid = MyDatabaseId; f_msg.m_nentries = 0; hash_seq_init(&hstat, dbentry->functions); while ((funcentry = (PgStat_StatFuncEntry *) hash_seq_search(&hstat)) != NULL) { Oid funcid = funcentry->functionid; CHECK_FOR_INTERRUPTS(); if (hash_search(htab, (void *) &funcid, HASH_FIND, NULL) != NULL) continue; /* * Not there, so add this function's Oid to the message */ f_msg.m_functionid[f_msg.m_nentries++] = funcid; /* * If the message is full, send it out and reinitialize to empty */ if (f_msg.m_nentries >= PGSTAT_NUM_FUNCPURGE) { len = offsetof(PgStat_MsgFuncpurge, m_functionid[0]) + f_msg.m_nentries * sizeof(Oid); pgstat_send(&f_msg, len); f_msg.m_nentries = 0; } } /* * Send the rest */ if (f_msg.m_nentries > 0) { len = offsetof(PgStat_MsgFuncpurge, m_functionid[0]) + f_msg.m_nentries * sizeof(Oid); pgstat_send(&f_msg, len); } hash_destroy(htab); } } /* ---------- * pgstat_collect_oids() - * * Collect the OIDs of all objects listed in the specified system catalog * into a temporary hash table. Caller should hash_destroy the result * when done with it. (However, we make the table in CurrentMemoryContext * so that it will be freed properly in event of an error.) * ---------- */ static HTAB * pgstat_collect_oids(Oid catalogid, AttrNumber anum_oid) { HTAB *htab; HASHCTL hash_ctl; Relation rel; TableScanDesc scan; HeapTuple tup; Snapshot snapshot; hash_ctl.keysize = sizeof(Oid); hash_ctl.entrysize = sizeof(Oid); hash_ctl.hcxt = CurrentMemoryContext; htab = hash_create("Temporary table of OIDs", PGSTAT_TAB_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_BLOBS | HASH_CONTEXT); rel = table_open(catalogid, AccessShareLock); snapshot = RegisterSnapshot(GetLatestSnapshot()); scan = table_beginscan(rel, snapshot, 0, NULL); while ((tup = heap_getnext(scan, ForwardScanDirection)) != NULL) { Oid thisoid; bool isnull; thisoid = heap_getattr(tup, anum_oid, RelationGetDescr(rel), &isnull); Assert(!isnull); CHECK_FOR_INTERRUPTS(); (void) hash_search(htab, (void *) &thisoid, HASH_ENTER, NULL); } table_endscan(scan); UnregisterSnapshot(snapshot); table_close(rel, AccessShareLock); return htab; } /* ---------- * pgstat_reset_counters() - * * Tell the statistics collector to reset counters for our database. * * Permission checking for this function is managed through the normal * GRANT system. * ---------- */ void pgstat_reset_counters(void) { PgStat_MsgResetcounter msg; if (pgStatSock == PGINVALID_SOCKET) return; pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETCOUNTER); msg.m_databaseid = MyDatabaseId; pgstat_send(&msg, sizeof(msg)); } /* ---------- * pgstat_reset_single_counter() - * * Tell the statistics collector to reset a single counter. * * Permission checking for this function is managed through the normal * GRANT system. * ---------- */ void pgstat_reset_single_counter(Oid objoid, PgStat_Single_Reset_Type type) { PgStat_MsgResetsinglecounter msg; if (pgStatSock == PGINVALID_SOCKET) return; pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETSINGLECOUNTER); msg.m_databaseid = MyDatabaseId; msg.m_resettype = type; msg.m_objectid = objoid; pgstat_send(&msg, sizeof(msg)); } /* ---------- * pgstat_reset_shared_counters() - * * Tell the statistics collector to reset cluster-wide shared counters. * * Permission checking for this function is managed through the normal * GRANT system. * ---------- */ void pgstat_reset_shared_counters(const char *target) { PgStat_MsgResetsharedcounter msg; if (pgStatSock == PGINVALID_SOCKET) return; if (strcmp(target, "archiver") == 0) msg.m_resettarget = RESET_ARCHIVER; else if (strcmp(target, "bgwriter") == 0) msg.m_resettarget = RESET_BGWRITER; else if (strcmp(target, "wal") == 0) msg.m_resettarget = RESET_WAL; else ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("unrecognized reset target: \"%s\"", target), errhint("Target must be \"archiver\", \"bgwriter\", or \"wal\"."))); pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETSHAREDCOUNTER); 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 == PGINVALID_SOCKET) return; pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_DUMMY); pgstat_send(&msg, sizeof(msg)); } /* ---------- * pgstat_send_inquiry() - * * Notify collector that we need fresh data. * ---------- */ static void pgstat_send_inquiry(TimestampTz clock_time, TimestampTz cutoff_time, Oid databaseid) { PgStat_MsgInquiry msg; pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_INQUIRY); msg.clock_time = clock_time; msg.cutoff_time = cutoff_time; msg.databaseid = databaseid; pgstat_send(&msg, sizeof(msg)); } /* * Ensure (sub)transaction stack entry for the given nest_level exists, adding * it if needed. */ PgStat_SubXactStatus * pgstat_xact_stack_level_get(int nest_level) { PgStat_SubXactStatus *xact_state; xact_state = pgStatXactStack; if (xact_state == NULL || xact_state->nest_level != nest_level) { xact_state = (PgStat_SubXactStatus *) MemoryContextAlloc(TopTransactionContext, sizeof(PgStat_SubXactStatus)); xact_state->nest_level = nest_level; xact_state->prev = pgStatXactStack; xact_state->first = NULL; pgStatXactStack = xact_state; } return xact_state; } /* ---------- * AtEOXact_PgStat * * Called from access/transam/xact.c at top-level transaction commit/abort. * ---------- */ void AtEOXact_PgStat(bool isCommit, bool parallel) { PgStat_SubXactStatus *xact_state; AtEOXact_PgStat_Database(isCommit, parallel); /* handle transactional stats information */ xact_state = pgStatXactStack; if (xact_state != NULL) { Assert(xact_state->nest_level == 1); Assert(xact_state->prev == NULL); AtEOXact_PgStat_Relations(xact_state, isCommit); } pgStatXactStack = NULL; /* Make sure any stats snapshot is thrown away */ pgstat_clear_snapshot(); } /* ---------- * AtEOSubXact_PgStat * * Called from access/transam/xact.c at subtransaction commit/abort. * ---------- */ void AtEOSubXact_PgStat(bool isCommit, int nestDepth) { PgStat_SubXactStatus *xact_state; /* merge the sub-transaction's transactional stats into the parent */ xact_state = pgStatXactStack; if (xact_state != NULL && xact_state->nest_level >= nestDepth) { /* delink xact_state from stack immediately to simplify reuse case */ pgStatXactStack = xact_state->prev; AtEOSubXact_PgStat_Relations(xact_state, isCommit, nestDepth); pfree(xact_state); } } /* * AtPrepare_PgStat * Save the transactional stats state at 2PC transaction prepare. */ void AtPrepare_PgStat(void) { PgStat_SubXactStatus *xact_state; xact_state = pgStatXactStack; if (xact_state != NULL) { Assert(xact_state->nest_level == 1); Assert(xact_state->prev == NULL); AtPrepare_PgStat_Relations(xact_state); } } /* * PostPrepare_PgStat * Clean up after successful PREPARE. * * Note: AtEOXact_PgStat is not called during PREPARE. */ void PostPrepare_PgStat(void) { PgStat_SubXactStatus *xact_state; /* * We don't bother to free any of the transactional state, since it's all * in TopTransactionContext and will go away anyway. */ xact_state = pgStatXactStack; if (xact_state != NULL) { Assert(xact_state->nest_level == 1); Assert(xact_state->prev == NULL); PostPrepare_PgStat_Relations(xact_state); } pgStatXactStack = NULL; /* Make sure any stats snapshot is thrown away */ pgstat_clear_snapshot(); } /* ---------- * 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_funcentry() - * * Support function for the SQL-callable pgstat* functions. Returns * the collected statistics for one function or NULL. * ---------- */ PgStat_StatFuncEntry * pgstat_fetch_stat_funcentry(Oid func_id) { PgStat_StatDBEntry *dbentry; PgStat_StatFuncEntry *funcentry = NULL; /* load the stats file if needed */ backend_read_statsfile(); /* Lookup our database, then find the requested function. */ dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId); if (dbentry != NULL && dbentry->functions != NULL) { funcentry = (PgStat_StatFuncEntry *) hash_search(dbentry->functions, (void *) &func_id, HASH_FIND, NULL); } return funcentry; } /* * --------- * pgstat_fetch_stat_archiver() - * * Support function for the SQL-callable pgstat* functions. Returns * a pointer to the archiver statistics struct. * --------- */ PgStat_ArchiverStats * pgstat_fetch_stat_archiver(void) { backend_read_statsfile(); return &archiverStats; } /* * --------- * pgstat_fetch_stat_bgwriter() - * * Support function for the SQL-callable pgstat* functions. Returns * a pointer to the bgwriter statistics struct. * --------- */ PgStat_BgWriterStats * pgstat_fetch_stat_bgwriter(void) { backend_read_statsfile(); return &globalStats.bgwriter; } /* * --------- * pgstat_fetch_stat_checkpointer() - * * Support function for the SQL-callable pgstat* functions. Returns * a pointer to the checkpointer statistics struct. * --------- */ PgStat_CheckpointerStats * pgstat_fetch_stat_checkpointer(void) { backend_read_statsfile(); return &globalStats.checkpointer; } /* * --------- * 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; } /* * --------- * pgstat_fetch_stat_wal() - * * Support function for the SQL-callable pgstat* functions. Returns * a pointer to the WAL statistics struct. * --------- */ PgStat_WalStats * pgstat_fetch_stat_wal(void) { backend_read_statsfile(); return &walStats; } /* * --------- * pgstat_fetch_slru() - * * Support function for the SQL-callable pgstat* functions. Returns * a pointer to the slru statistics struct. * --------- */ PgStat_SLRUStats * pgstat_fetch_slru(void) { backend_read_statsfile(); return slruStats; } /* * --------- * pgstat_fetch_replslot() - * * Support function for the SQL-callable pgstat* functions. Returns * a pointer to the replication slot statistics struct. * --------- */ PgStat_StatReplSlotEntry * pgstat_fetch_replslot(NameData slotname) { backend_read_statsfile(); return pgstat_get_replslot_entry(slotname, false); } /* * --------- * pgstat_fetch_stat_subscription() - * * Support function for the SQL-callable pgstat* functions. Returns * the collected statistics for one subscription or NULL. * --------- */ PgStat_StatSubEntry * pgstat_fetch_stat_subscription(Oid subid) { /* Load the stats file if needed */ backend_read_statsfile(); return pgstat_get_subscription_entry(subid, false); } /* * 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. */ static void pgstat_shutdown_hook(int code, Datum arg) { Assert(!pgstat_is_shutdown); /* * If we got as far as discovering our own database ID, we can report what * we did to the collector. Otherwise, we'd be sending an invalid * database ID, so forget it. (This means that accesses to pg_database * during failed backend starts might never get counted.) */ if (OidIsValid(MyDatabaseId)) pgstat_report_stat(true); #ifdef USE_ASSERT_CHECKING pgstat_is_shutdown = true; #endif } /* ---------- * pgstat_initialize() - * * Initialize pgstats state, and set up our on-proc-exit hook. Called from * BaseInit(). * * NOTE: MyDatabaseId isn't set yet; so the shutdown hook has to be careful. * ---------- */ void pgstat_initialize(void) { Assert(!pgstat_is_initialized); pgstat_wal_initialize(); /* Set up a process-exit hook to clean up */ before_shmem_exit(pgstat_shutdown_hook, 0); #ifdef USE_ASSERT_CHECKING pgstat_is_initialized = true; #endif } /* ------------------------------------------------------------ * Local support functions follow * ------------------------------------------------------------ */ /* ---------- * pgstat_setheader() - * * Set common header fields in a statistics message * ---------- */ void pgstat_setheader(PgStat_MsgHdr *hdr, StatMsgType mtype) { hdr->m_type = mtype; } /* ---------- * pgstat_send() - * * Send out one statistics message to the collector * ---------- */ void pgstat_send(void *msg, int len) { int rc; pgstat_assert_is_up(); if (pgStatSock == PGINVALID_SOCKET) 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 } /* ---------- * 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[]) { int len; PgStat_Msg msg; int wr; WaitEvent event; WaitEventSet *wes; /* * Ignore all signals usually bound to some action in the postmaster, * except SIGHUP and SIGQUIT. Note we don't need a SIGUSR1 handler to * support latch operations, because we only use a local latch. */ pqsignal(SIGHUP, SignalHandlerForConfigReload); pqsignal(SIGINT, SIG_IGN); pqsignal(SIGTERM, SIG_IGN); pqsignal(SIGQUIT, SignalHandlerForShutdownRequest); pqsignal(SIGALRM, SIG_IGN); pqsignal(SIGPIPE, SIG_IGN); pqsignal(SIGUSR1, SIG_IGN); pqsignal(SIGUSR2, SIG_IGN); /* Reset some signals that are accepted by postmaster but not here */ pqsignal(SIGCHLD, SIG_DFL); PG_SETMASK(&UnBlockSig); MyBackendType = B_STATS_COLLECTOR; init_ps_display(NULL); /* * Read in existing stats files or initialize the stats to zero. */ pgStatRunningInCollector = true; pgStatDBHash = pgstat_read_statsfiles(InvalidOid, true, true); /* Prepare to wait for our latch or data in our socket. */ wes = CreateWaitEventSet(CurrentMemoryContext, 3); AddWaitEventToSet(wes, WL_LATCH_SET, PGINVALID_SOCKET, MyLatch, NULL); AddWaitEventToSet(wes, WL_POSTMASTER_DEATH, PGINVALID_SOCKET, NULL, NULL); AddWaitEventToSet(wes, WL_SOCKET_READABLE, pgStatSock, NULL, NULL); /* * 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 ResetLatch/WaitLatch after * every message; instead, do that only after a recv() fails to obtain a * message. (This effectively means that if backends are sending us stuff * like mad, we won't notice postmaster death until things slack off a * bit; which seems fine.) To do that, we have an inner loop that * iterates as long as recv() succeeds. We do check ConfigReloadPending * inside the inner loop, which means that such interrupts will get * serviced but the latch won't get cleared until next time there is a * break in the action. */ for (;;) { /* Clear any already-pending wakeups */ ResetLatch(MyLatch); /* * Quit if we get SIGQUIT from the postmaster. */ if (ShutdownRequestPending) break; /* * Inner loop iterates as long as we keep getting messages, or until * ShutdownRequestPending becomes set. */ while (!ShutdownRequestPending) { /* * Reload configuration if we got SIGHUP from the postmaster. */ if (ConfigReloadPending) { ConfigReloadPending = false; ProcessConfigFile(PGC_SIGHUP); } /* * Write the stats file(s) if a new request has arrived that is * not satisfied by existing file(s). */ if (pgstat_write_statsfile_needed()) pgstat_write_statsfiles(false, false); /* * Try to receive and process a message. This will not block, * since the socket is set to non-blocking mode. * * XXX On Windows, we have to force pgwin32_recv to cooperate, * despite the previous use of pg_set_noblock() on the socket. * This is extremely broken and should be fixed someday. */ #ifdef WIN32 pgwin32_noblock = 1; #endif len = recv(pgStatSock, (char *) &msg, sizeof(PgStat_Msg), 0); #ifdef WIN32 pgwin32_noblock = 0; #endif if (len < 0) { if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) break; /* out of inner loop */ 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_INQUIRY: pgstat_recv_inquiry(&msg.msg_inquiry, len); break; case PGSTAT_MTYPE_TABSTAT: pgstat_recv_tabstat(&msg.msg_tabstat, len); break; case PGSTAT_MTYPE_TABPURGE: pgstat_recv_tabpurge(&msg.msg_tabpurge, len); break; case PGSTAT_MTYPE_DROPDB: pgstat_recv_dropdb(&msg.msg_dropdb, len); break; case PGSTAT_MTYPE_RESETCOUNTER: pgstat_recv_resetcounter(&msg.msg_resetcounter, len); break; case PGSTAT_MTYPE_RESETSHAREDCOUNTER: pgstat_recv_resetsharedcounter(&msg.msg_resetsharedcounter, len); break; case PGSTAT_MTYPE_RESETSINGLECOUNTER: pgstat_recv_resetsinglecounter(&msg.msg_resetsinglecounter, len); break; case PGSTAT_MTYPE_RESETSLRUCOUNTER: pgstat_recv_resetslrucounter(&msg.msg_resetslrucounter, len); break; case PGSTAT_MTYPE_RESETREPLSLOTCOUNTER: pgstat_recv_resetreplslotcounter(&msg.msg_resetreplslotcounter, len); break; case PGSTAT_MTYPE_RESETSUBCOUNTER: pgstat_recv_resetsubcounter(&msg.msg_resetsubcounter, len); break; case PGSTAT_MTYPE_AUTOVAC_START: pgstat_recv_autovac(&msg.msg_autovacuum_start, len); break; case PGSTAT_MTYPE_VACUUM: pgstat_recv_vacuum(&msg.msg_vacuum, len); break; case PGSTAT_MTYPE_ANALYZE: pgstat_recv_analyze(&msg.msg_analyze, len); break; case PGSTAT_MTYPE_ARCHIVER: pgstat_recv_archiver(&msg.msg_archiver, len); break; case PGSTAT_MTYPE_BGWRITER: pgstat_recv_bgwriter(&msg.msg_bgwriter, len); break; case PGSTAT_MTYPE_CHECKPOINTER: pgstat_recv_checkpointer(&msg.msg_checkpointer, len); break; case PGSTAT_MTYPE_WAL: pgstat_recv_wal(&msg.msg_wal, len); break; case PGSTAT_MTYPE_SLRU: pgstat_recv_slru(&msg.msg_slru, len); break; case PGSTAT_MTYPE_FUNCSTAT: pgstat_recv_funcstat(&msg.msg_funcstat, len); break; case PGSTAT_MTYPE_FUNCPURGE: pgstat_recv_funcpurge(&msg.msg_funcpurge, len); break; case PGSTAT_MTYPE_RECOVERYCONFLICT: pgstat_recv_recoveryconflict(&msg.msg_recoveryconflict, len); break; case PGSTAT_MTYPE_DEADLOCK: pgstat_recv_deadlock(&msg.msg_deadlock, len); break; case PGSTAT_MTYPE_TEMPFILE: pgstat_recv_tempfile(&msg.msg_tempfile, len); break; case PGSTAT_MTYPE_CHECKSUMFAILURE: pgstat_recv_checksum_failure(&msg.msg_checksumfailure, len); break; case PGSTAT_MTYPE_REPLSLOT: pgstat_recv_replslot(&msg.msg_replslot, len); break; case PGSTAT_MTYPE_CONNECT: pgstat_recv_connect(&msg.msg_connect, len); break; case PGSTAT_MTYPE_DISCONNECT: pgstat_recv_disconnect(&msg.msg_disconnect, len); break; case PGSTAT_MTYPE_SUBSCRIPTIONDROP: pgstat_recv_subscription_drop(&msg.msg_subscriptiondrop, len); break; case PGSTAT_MTYPE_SUBSCRIPTIONERROR: pgstat_recv_subscription_error(&msg.msg_subscriptionerror, len); break; default: break; } } /* end of inner message-processing loop */ /* Sleep until there's something to do */ #ifndef WIN32 wr = WaitEventSetWait(wes, -1L, &event, 1, WAIT_EVENT_PGSTAT_MAIN); #else /* * Windows, at least in its Windows Server 2003 R2 incarnation, * sometimes loses FD_READ events. Waking up and retrying the recv() * fixes that, so don't sleep indefinitely. This is a crock of the * first water, but until somebody wants to debug exactly what's * happening there, this is the best we can do. The two-second * timeout matches our pre-9.2 behavior, and needs to be short enough * to not provoke "using stale statistics" complaints from * backend_read_statsfile. */ wr = WaitEventSetWait(wes, 2 * 1000L /* msec */ , &event, 1, WAIT_EVENT_PGSTAT_MAIN); #endif /* * Emergency bailout if postmaster has died. This is to avoid the * necessity for manual cleanup of all postmaster children. */ if (wr == 1 && event.events == WL_POSTMASTER_DEATH) break; } /* end of outer loop */ /* * Save the final stats to reuse at next startup. */ pgstat_write_statsfiles(true, true); FreeWaitEventSet(wes); exit(0); } /* * Subroutine to clear stats in a database entry * * Tables and functions hashes are initialized to empty. */ static void reset_dbentry_counters(PgStat_StatDBEntry *dbentry) { HASHCTL hash_ctl; dbentry->n_xact_commit = 0; dbentry->n_xact_rollback = 0; dbentry->n_blocks_fetched = 0; dbentry->n_blocks_hit = 0; dbentry->n_tuples_returned = 0; dbentry->n_tuples_fetched = 0; dbentry->n_tuples_inserted = 0; dbentry->n_tuples_updated = 0; dbentry->n_tuples_deleted = 0; dbentry->last_autovac_time = 0; dbentry->n_conflict_tablespace = 0; dbentry->n_conflict_lock = 0; dbentry->n_conflict_snapshot = 0; dbentry->n_conflict_bufferpin = 0; dbentry->n_conflict_startup_deadlock = 0; dbentry->n_temp_files = 0; dbentry->n_temp_bytes = 0; dbentry->n_deadlocks = 0; dbentry->n_checksum_failures = 0; dbentry->last_checksum_failure = 0; dbentry->n_block_read_time = 0; dbentry->n_block_write_time = 0; dbentry->n_sessions = 0; dbentry->total_session_time = 0; dbentry->total_active_time = 0; dbentry->total_idle_in_xact_time = 0; dbentry->n_sessions_abandoned = 0; dbentry->n_sessions_fatal = 0; dbentry->n_sessions_killed = 0; dbentry->stat_reset_timestamp = GetCurrentTimestamp(); dbentry->stats_timestamp = 0; hash_ctl.keysize = sizeof(Oid); hash_ctl.entrysize = sizeof(PgStat_StatTabEntry); dbentry->tables = hash_create("Per-database table", PGSTAT_TAB_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_BLOBS); hash_ctl.keysize = sizeof(Oid); hash_ctl.entrysize = sizeof(PgStat_StatFuncEntry); dbentry->functions = hash_create("Per-database function", PGSTAT_FUNCTION_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_BLOBS); } /* * 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. This creates empty hash tables * for tables and functions, too. */ if (!found) reset_dbentry_counters(result); return result; } /* * Lookup the hash table entry for the specified table. If no hash * table entry exists, initialize it, if the create parameter is true. * Else, return NULL. */ static PgStat_StatTabEntry * pgstat_get_tab_entry(PgStat_StatDBEntry *dbentry, Oid tableoid, bool create) { PgStat_StatTabEntry *result; bool found; HASHACTION action = (create ? HASH_ENTER : HASH_FIND); /* Lookup or create the hash table entry for this table */ result = (PgStat_StatTabEntry *) hash_search(dbentry->tables, &tableoid, action, &found); if (!create && !found) return NULL; /* If not found, initialize the new one. */ if (!found) { result->numscans = 0; result->tuples_returned = 0; result->tuples_fetched = 0; result->tuples_inserted = 0; result->tuples_updated = 0; result->tuples_deleted = 0; result->tuples_hot_updated = 0; result->n_live_tuples = 0; result->n_dead_tuples = 0; result->changes_since_analyze = 0; result->inserts_since_vacuum = 0; result->blocks_fetched = 0; result->blocks_hit = 0; result->vacuum_timestamp = 0; result->vacuum_count = 0; result->autovac_vacuum_timestamp = 0; result->autovac_vacuum_count = 0; result->analyze_timestamp = 0; result->analyze_count = 0; result->autovac_analyze_timestamp = 0; result->autovac_analyze_count = 0; } return result; } /* ---------- * pgstat_write_statsfiles() - * Write the global statistics file, as well as requested DB files. * * 'permanent' specifies writing to the permanent files not temporary ones. * When true (happens only when the collector is shutting down), also remove * the temporary files so that backends starting up under a new postmaster * can't read old data before the new collector is ready. * * When 'allDbs' is false, only the requested databases (listed in * pending_write_requests) will be written; otherwise, all databases * will be written. * ---------- */ static void pgstat_write_statsfiles(bool permanent, bool allDbs) { HASH_SEQ_STATUS hstat; PgStat_StatDBEntry *dbentry; FILE *fpout; int32 format_id; const char *tmpfile = permanent ? PGSTAT_STAT_PERMANENT_TMPFILE : pgstat_stat_tmpname; const char *statfile = permanent ? PGSTAT_STAT_PERMANENT_FILENAME : pgstat_stat_filename; int rc; elog(DEBUG2, "writing stats file \"%s\"", statfile); /* * Open the statistics temp file to write out the current values. */ fpout = AllocateFile(tmpfile, PG_BINARY_W); if (fpout == NULL) { ereport(LOG, (errcode_for_file_access(), errmsg("could not open temporary statistics file \"%s\": %m", tmpfile))); return; } /* * Set the timestamp of the stats file. */ globalStats.stats_timestamp = GetCurrentTimestamp(); /* * Write the file header --- currently just a format ID. */ format_id = PGSTAT_FILE_FORMAT_ID; rc = fwrite(&format_id, sizeof(format_id), 1, fpout); (void) rc; /* we'll check for error with ferror */ /* * Write global stats struct */ rc = fwrite(&globalStats, sizeof(globalStats), 1, fpout); (void) rc; /* we'll check for error with ferror */ /* * Write archiver stats struct */ rc = fwrite(&archiverStats, sizeof(archiverStats), 1, fpout); (void) rc; /* we'll check for error with ferror */ /* * Write WAL stats struct */ rc = fwrite(&walStats, sizeof(walStats), 1, fpout); (void) rc; /* we'll check for error with ferror */ /* * Write SLRU stats struct */ rc = fwrite(slruStats, sizeof(slruStats), 1, fpout); (void) rc; /* we'll check for error with ferror */ /* * Walk through the database table. */ hash_seq_init(&hstat, pgStatDBHash); while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL) { /* * Write out the table and function stats for this DB into the * appropriate per-DB stat file, if required. */ if (allDbs || pgstat_db_requested(dbentry->databaseid)) { /* Make DB's timestamp consistent with the global stats */ dbentry->stats_timestamp = globalStats.stats_timestamp; pgstat_write_db_statsfile(dbentry, permanent); } /* * Write out the DB entry. We don't write the tables or functions * pointers, since they're of no use to any other process. */ fputc('D', fpout); rc = fwrite(dbentry, offsetof(PgStat_StatDBEntry, tables), 1, fpout); (void) rc; /* we'll check for error with ferror */ } /* * Write replication slot stats struct */ if (replSlotStatHash) { PgStat_StatReplSlotEntry *slotent; hash_seq_init(&hstat, replSlotStatHash); while ((slotent = (PgStat_StatReplSlotEntry *) hash_seq_search(&hstat)) != NULL) { fputc('R', fpout); rc = fwrite(slotent, sizeof(PgStat_StatReplSlotEntry), 1, fpout); (void) rc; /* we'll check for error with ferror */ } } /* * Write subscription stats struct */ if (subscriptionStatHash) { PgStat_StatSubEntry *subentry; hash_seq_init(&hstat, subscriptionStatHash); while ((subentry = (PgStat_StatSubEntry *) hash_seq_search(&hstat)) != NULL) { fputc('S', fpout); rc = fwrite(subentry, sizeof(PgStat_StatSubEntry), 1, fpout); (void) rc; /* we'll check for error with ferror */ } } /* * 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", tmpfile))); FreeFile(fpout); unlink(tmpfile); } else if (FreeFile(fpout) < 0) { ereport(LOG, (errcode_for_file_access(), errmsg("could not close temporary statistics file \"%s\": %m", tmpfile))); unlink(tmpfile); } else if (rename(tmpfile, statfile) < 0) { ereport(LOG, (errcode_for_file_access(), errmsg("could not rename temporary statistics file \"%s\" to \"%s\": %m", tmpfile, statfile))); unlink(tmpfile); } if (permanent) unlink(pgstat_stat_filename); /* * Now throw away the list of requests. Note that requests sent after we * started the write are still waiting on the network socket. */ list_free(pending_write_requests); pending_write_requests = NIL; } /* * return the filename for a DB stat file; filename is the output buffer, * of length len. */ static void get_dbstat_filename(bool permanent, bool tempname, Oid databaseid, char *filename, int len) { int printed; /* NB -- pgstat_reset_remove_files knows about the pattern this uses */ printed = snprintf(filename, len, "%s/db_%u.%s", permanent ? PGSTAT_STAT_PERMANENT_DIRECTORY : pgstat_stat_directory, databaseid, tempname ? "tmp" : "stat"); if (printed >= len) elog(ERROR, "overlength pgstat path"); } /* ---------- * pgstat_write_db_statsfile() - * Write the stat file for a single database. * * If writing to the permanent file (happens when the collector is * shutting down only), remove the temporary file so that backends * starting up under a new postmaster can't read the old data before * the new collector is ready. * ---------- */ static void pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent) { HASH_SEQ_STATUS tstat; HASH_SEQ_STATUS fstat; PgStat_StatTabEntry *tabentry; PgStat_StatFuncEntry *funcentry; FILE *fpout; int32 format_id; Oid dbid = dbentry->databaseid; int rc; char tmpfile[MAXPGPATH]; char statfile[MAXPGPATH]; get_dbstat_filename(permanent, true, dbid, tmpfile, MAXPGPATH); get_dbstat_filename(permanent, false, dbid, statfile, MAXPGPATH); elog(DEBUG2, "writing stats file \"%s\"", statfile); /* * Open the statistics temp file to write out the current values. */ fpout = AllocateFile(tmpfile, PG_BINARY_W); if (fpout == NULL) { ereport(LOG, (errcode_for_file_access(), errmsg("could not open temporary statistics file \"%s\": %m", tmpfile))); return; } /* * Write the file header --- currently just a format ID. */ format_id = PGSTAT_FILE_FORMAT_ID; rc = fwrite(&format_id, sizeof(format_id), 1, fpout); (void) rc; /* we'll check for error with ferror */ /* * 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); rc = fwrite(tabentry, sizeof(PgStat_StatTabEntry), 1, fpout); (void) rc; /* we'll check for error with ferror */ } /* * Walk through the database's function stats table. */ hash_seq_init(&fstat, dbentry->functions); while ((funcentry = (PgStat_StatFuncEntry *) hash_seq_search(&fstat)) != NULL) { fputc('F', fpout); rc = fwrite(funcentry, sizeof(PgStat_StatFuncEntry), 1, fpout); (void) rc; /* we'll check for error with ferror */ } /* * 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", tmpfile))); FreeFile(fpout); unlink(tmpfile); } else if (FreeFile(fpout) < 0) { ereport(LOG, (errcode_for_file_access(), errmsg("could not close temporary statistics file \"%s\": %m", tmpfile))); unlink(tmpfile); } else if (rename(tmpfile, statfile) < 0) { ereport(LOG, (errcode_for_file_access(), errmsg("could not rename temporary statistics file \"%s\" to \"%s\": %m", tmpfile, statfile))); unlink(tmpfile); } if (permanent) { get_dbstat_filename(false, false, dbid, statfile, MAXPGPATH); elog(DEBUG2, "removing temporary stats file \"%s\"", statfile); unlink(statfile); } } /* ---------- * pgstat_read_statsfiles() - * * Reads in some existing statistics collector files and returns the * databases hash table that is the top level of the data. * * If 'onlydb' is not InvalidOid, it means we only want data for that DB * plus the shared catalogs ("DB 0"). We'll still populate the DB hash * table for all databases, but we don't bother even creating table/function * hash tables for other databases. * * 'permanent' specifies reading from the permanent files not temporary ones. * When true (happens only when the collector is starting up), remove the * files after reading; the in-memory status is now authoritative, and the * files would be out of date in case somebody else reads them. * * If a 'deep' read is requested, table/function stats are read, otherwise * the table/function hash tables remain empty. * ---------- */ static HTAB * pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep) { PgStat_StatDBEntry *dbentry; PgStat_StatDBEntry dbbuf; HASHCTL hash_ctl; HTAB *dbhash; FILE *fpin; int32 format_id; bool found; const char *statfile = permanent ? PGSTAT_STAT_PERMANENT_FILENAME : pgstat_stat_filename; int i; TimestampTz ts; /* * The tables will live in pgStatLocalContext. */ pgstat_setup_memcxt(); /* * Create the DB hashtable */ hash_ctl.keysize = sizeof(Oid); hash_ctl.entrysize = sizeof(PgStat_StatDBEntry); hash_ctl.hcxt = pgStatLocalContext; dbhash = hash_create("Databases hash", PGSTAT_DB_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_BLOBS | HASH_CONTEXT); /* * Clear out global, archiver, WAL and SLRU statistics so they start from * zero in case we can't load an existing statsfile. */ memset(&globalStats, 0, sizeof(globalStats)); memset(&archiverStats, 0, sizeof(archiverStats)); memset(&walStats, 0, sizeof(walStats)); memset(&slruStats, 0, sizeof(slruStats)); /* * Set the current timestamp (will be kept only in case we can't load an * existing statsfile). */ ts = GetCurrentTimestamp(); globalStats.bgwriter.stat_reset_timestamp = ts; archiverStats.stat_reset_timestamp = ts; walStats.stat_reset_timestamp = ts; /* * Set the same reset timestamp for all SLRU items too. */ for (i = 0; i < SLRU_NUM_ELEMENTS; i++) slruStats[i].stat_reset_timestamp = ts; /* * Try to open the stats file. If it doesn't exist, the backends simply * return zero for anything and the collector simply starts from scratch * with empty counters. * * ENOENT is a possibility if the stats collector is not running or has * not yet written the stats file the first time. Any other failure * condition is suspicious. */ if ((fpin = AllocateFile(statfile, PG_BINARY_R)) == NULL) { if (errno != ENOENT) ereport(pgStatRunningInCollector ? LOG : WARNING, (errcode_for_file_access(), errmsg("could not open statistics file \"%s\": %m", statfile))); 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 statistics file \"%s\"", statfile))); goto done; } /* * Read global stats struct */ if (fread(&globalStats, 1, sizeof(globalStats), fpin) != sizeof(globalStats)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); memset(&globalStats, 0, sizeof(globalStats)); goto done; } /* * In the collector, disregard the timestamp we read from the permanent * stats file; we should be willing to write a temp stats file immediately * upon the first request from any backend. This only matters if the old * file's timestamp is less than PGSTAT_STAT_INTERVAL ago, but that's not * an unusual scenario. */ if (pgStatRunningInCollector) globalStats.stats_timestamp = 0; /* * Read archiver stats struct */ if (fread(&archiverStats, 1, sizeof(archiverStats), fpin) != sizeof(archiverStats)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); memset(&archiverStats, 0, sizeof(archiverStats)); goto done; } /* * Read WAL stats struct */ if (fread(&walStats, 1, sizeof(walStats), fpin) != sizeof(walStats)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); memset(&walStats, 0, sizeof(walStats)); goto done; } /* * Read SLRU stats struct */ if (fread(slruStats, 1, sizeof(slruStats), fpin) != sizeof(slruStats)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); memset(&slruStats, 0, sizeof(slruStats)); 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. */ case 'D': if (fread(&dbbuf, 1, offsetof(PgStat_StatDBEntry, tables), fpin) != offsetof(PgStat_StatDBEntry, tables)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); 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 statistics file \"%s\"", statfile))); goto done; } memcpy(dbentry, &dbbuf, sizeof(PgStat_StatDBEntry)); dbentry->tables = NULL; dbentry->functions = NULL; /* * In the collector, disregard the timestamp we read from the * permanent stats file; we should be willing to write a temp * stats file immediately upon the first request from any * backend. */ if (pgStatRunningInCollector) dbentry->stats_timestamp = 0; /* * Don't create tables/functions hashtables for uninteresting * databases. */ if (onlydb != InvalidOid) { if (dbbuf.databaseid != onlydb && dbbuf.databaseid != InvalidOid) break; } hash_ctl.keysize = sizeof(Oid); hash_ctl.entrysize = sizeof(PgStat_StatTabEntry); hash_ctl.hcxt = pgStatLocalContext; dbentry->tables = hash_create("Per-database table", PGSTAT_TAB_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_BLOBS | HASH_CONTEXT); hash_ctl.keysize = sizeof(Oid); hash_ctl.entrysize = sizeof(PgStat_StatFuncEntry); hash_ctl.hcxt = pgStatLocalContext; dbentry->functions = hash_create("Per-database function", PGSTAT_FUNCTION_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_BLOBS | HASH_CONTEXT); /* * If requested, read the data from the database-specific * file. Otherwise we just leave the hashtables empty. */ if (deep) pgstat_read_db_statsfile(dbentry->databaseid, dbentry->tables, dbentry->functions, permanent); break; /* * 'R' A PgStat_StatReplSlotEntry struct describing a * replication slot follows. */ case 'R': { PgStat_StatReplSlotEntry slotbuf; PgStat_StatReplSlotEntry *slotent; if (fread(&slotbuf, 1, sizeof(PgStat_StatReplSlotEntry), fpin) != sizeof(PgStat_StatReplSlotEntry)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); goto done; } /* Create hash table if we don't have it already. */ if (replSlotStatHash == NULL) { HASHCTL hash_ctl; hash_ctl.keysize = sizeof(NameData); hash_ctl.entrysize = sizeof(PgStat_StatReplSlotEntry); hash_ctl.hcxt = pgStatLocalContext; replSlotStatHash = hash_create("Replication slots hash", PGSTAT_REPLSLOT_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_BLOBS | HASH_CONTEXT); } slotent = (PgStat_StatReplSlotEntry *) hash_search(replSlotStatHash, (void *) &slotbuf.slotname, HASH_ENTER, NULL); memcpy(slotent, &slotbuf, sizeof(PgStat_StatReplSlotEntry)); break; } /* * 'S' A PgStat_StatSubEntry struct describing subscription * statistics. */ case 'S': { PgStat_StatSubEntry subbuf; PgStat_StatSubEntry *subentry; if (fread(&subbuf, 1, sizeof(PgStat_StatSubEntry), fpin) != sizeof(PgStat_StatSubEntry)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); goto done; } if (subscriptionStatHash == NULL) { HASHCTL hash_ctl; hash_ctl.keysize = sizeof(Oid); hash_ctl.entrysize = sizeof(PgStat_StatSubEntry); hash_ctl.hcxt = pgStatLocalContext; subscriptionStatHash = hash_create("Subscription hash", PGSTAT_SUBSCRIPTION_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_BLOBS | HASH_CONTEXT); } subentry = (PgStat_StatSubEntry *) hash_search(subscriptionStatHash, (void *) &subbuf.subid, HASH_ENTER, NULL); memcpy(subentry, &subbuf, sizeof(subbuf)); break; } case 'E': goto done; default: ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); goto done; } } done: FreeFile(fpin); /* If requested to read the permanent file, also get rid of it. */ if (permanent) { elog(DEBUG2, "removing permanent stats file \"%s\"", statfile); unlink(statfile); } return dbhash; } /* ---------- * pgstat_read_db_statsfile() - * * Reads in the existing statistics collector file for the given database, * filling the passed-in tables and functions hash tables. * * As in pgstat_read_statsfiles, if the permanent file is requested, it is * removed after reading. * * Note: this code has the ability to skip storing per-table or per-function * data, if NULL is passed for the corresponding hashtable. That's not used * at the moment though. * ---------- */ static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, bool permanent) { PgStat_StatTabEntry *tabentry; PgStat_StatTabEntry tabbuf; PgStat_StatFuncEntry funcbuf; PgStat_StatFuncEntry *funcentry; FILE *fpin; int32 format_id; bool found; char statfile[MAXPGPATH]; get_dbstat_filename(permanent, false, databaseid, statfile, MAXPGPATH); /* * Try to open the stats file. If it doesn't exist, the backends simply * return zero for anything and the collector simply starts from scratch * with empty counters. * * ENOENT is a possibility if the stats collector is not running or has * not yet written the stats file the first time. Any other failure * condition is suspicious. */ if ((fpin = AllocateFile(statfile, PG_BINARY_R)) == NULL) { if (errno != ENOENT) ereport(pgStatRunningInCollector ? LOG : WARNING, (errcode_for_file_access(), errmsg("could not open statistics file \"%s\": %m", statfile))); return; } /* * 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 statistics file \"%s\"", statfile))); goto done; } /* * We found an existing collector stats file. Read it and put all the * hashtable entries into place. */ for (;;) { switch (fgetc(fpin)) { /* * 'T' A PgStat_StatTabEntry follows. */ case 'T': if (fread(&tabbuf, 1, sizeof(PgStat_StatTabEntry), fpin) != sizeof(PgStat_StatTabEntry)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); goto done; } /* * Skip if table data not wanted. */ if (tabhash == NULL) break; tabentry = (PgStat_StatTabEntry *) hash_search(tabhash, (void *) &tabbuf.tableid, HASH_ENTER, &found); if (found) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); goto done; } memcpy(tabentry, &tabbuf, sizeof(tabbuf)); break; /* * 'F' A PgStat_StatFuncEntry follows. */ case 'F': if (fread(&funcbuf, 1, sizeof(PgStat_StatFuncEntry), fpin) != sizeof(PgStat_StatFuncEntry)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); goto done; } /* * Skip if function data not wanted. */ if (funchash == NULL) break; funcentry = (PgStat_StatFuncEntry *) hash_search(funchash, (void *) &funcbuf.functionid, HASH_ENTER, &found); if (found) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); goto done; } memcpy(funcentry, &funcbuf, sizeof(funcbuf)); break; /* * 'E' The EOF marker of a complete stats file. */ case 'E': goto done; default: ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); goto done; } } done: FreeFile(fpin); if (permanent) { elog(DEBUG2, "removing permanent stats file \"%s\"", statfile); unlink(statfile); } } /* ---------- * pgstat_read_db_statsfile_timestamp() - * * Attempt to determine the timestamp of the last db statfile write. * Returns true if successful; the timestamp is stored in *ts. The caller must * rely on timestamp stored in *ts iff the function returns true. * * This needs to be careful about handling databases for which no stats file * exists, such as databases without a stat entry or those not yet written: * * - if there's a database entry in the global file, return the corresponding * stats_timestamp value. * * - if there's no db stat entry (e.g. for a new or inactive database), * there's no stats_timestamp value, but also nothing to write so we return * the timestamp of the global statfile. * ---------- */ static bool pgstat_read_db_statsfile_timestamp(Oid databaseid, bool permanent, TimestampTz *ts) { PgStat_StatDBEntry dbentry; PgStat_GlobalStats myGlobalStats; PgStat_ArchiverStats myArchiverStats; PgStat_WalStats myWalStats; PgStat_SLRUStats mySLRUStats[SLRU_NUM_ELEMENTS]; PgStat_StatReplSlotEntry myReplSlotStats; PgStat_StatSubEntry mySubStats; FILE *fpin; int32 format_id; const char *statfile = permanent ? PGSTAT_STAT_PERMANENT_FILENAME : pgstat_stat_filename; /* * Try to open the stats file. As above, anything but ENOENT is worthy of * complaining about. */ if ((fpin = AllocateFile(statfile, PG_BINARY_R)) == NULL) { if (errno != ENOENT) ereport(pgStatRunningInCollector ? LOG : WARNING, (errcode_for_file_access(), errmsg("could not open statistics file \"%s\": %m", statfile))); return false; } /* * 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 statistics file \"%s\"", statfile))); FreeFile(fpin); return false; } /* * Read global stats struct */ if (fread(&myGlobalStats, 1, sizeof(myGlobalStats), fpin) != sizeof(myGlobalStats)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); FreeFile(fpin); return false; } /* * Read archiver stats struct */ if (fread(&myArchiverStats, 1, sizeof(myArchiverStats), fpin) != sizeof(myArchiverStats)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); FreeFile(fpin); return false; } /* * Read WAL stats struct */ if (fread(&myWalStats, 1, sizeof(myWalStats), fpin) != sizeof(myWalStats)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); FreeFile(fpin); return false; } /* * Read SLRU stats struct */ if (fread(mySLRUStats, 1, sizeof(mySLRUStats), fpin) != sizeof(mySLRUStats)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); FreeFile(fpin); return false; } /* By default, we're going to return the timestamp of the global file. */ *ts = myGlobalStats.stats_timestamp; /* * We found an existing collector stats file. Read it and look for a * record for the requested database. If found, use its timestamp. */ for (;;) { switch (fgetc(fpin)) { /* * 'D' A PgStat_StatDBEntry struct describing a database * follows. */ case 'D': if (fread(&dbentry, 1, offsetof(PgStat_StatDBEntry, tables), fpin) != offsetof(PgStat_StatDBEntry, tables)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); FreeFile(fpin); return false; } /* * If this is the DB we're looking for, save its timestamp and * we're done. */ if (dbentry.databaseid == databaseid) { *ts = dbentry.stats_timestamp; goto done; } break; /* * 'R' A PgStat_StatReplSlotEntry struct describing a * replication slot follows. */ case 'R': if (fread(&myReplSlotStats, 1, sizeof(PgStat_StatReplSlotEntry), fpin) != sizeof(PgStat_StatReplSlotEntry)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); FreeFile(fpin); return false; } break; /* * 'S' A PgStat_StatSubEntry struct describing subscription * statistics follows. */ case 'S': if (fread(&mySubStats, 1, sizeof(PgStat_StatSubEntry), fpin) != sizeof(PgStat_StatSubEntry)) { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); FreeFile(fpin); return false; } break; case 'E': goto done; default: { ereport(pgStatRunningInCollector ? LOG : WARNING, (errmsg("corrupted statistics file \"%s\"", statfile))); FreeFile(fpin); return false; } } } done: FreeFile(fpin); return true; } /* * 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) { TimestampTz min_ts = 0; TimestampTz ref_ts = 0; Oid inquiry_db; int count; pgstat_assert_is_up(); /* already read it? */ if (pgStatDBHash) return; Assert(!pgStatRunningInCollector); /* * In a normal backend, we check staleness of the data for our own DB, and * so we send MyDatabaseId in inquiry messages. In the autovac launcher, * check staleness of the shared-catalog data, and send InvalidOid in * inquiry messages so as not to force writing unnecessary data. */ if (IsAutoVacuumLauncherProcess()) inquiry_db = InvalidOid; else inquiry_db = MyDatabaseId; /* * Loop until fresh enough stats file is available or we ran out of time. * The stats inquiry message is sent repeatedly in case collector drops * it; but not every single time, as that just swamps the collector. */ for (count = 0; count < PGSTAT_POLL_LOOP_COUNT; count++) { bool ok; TimestampTz file_ts = 0; TimestampTz cur_ts; CHECK_FOR_INTERRUPTS(); ok = pgstat_read_db_statsfile_timestamp(inquiry_db, false, &file_ts); cur_ts = GetCurrentTimestamp(); /* Calculate min acceptable timestamp, if we didn't already */ if (count == 0 || cur_ts < ref_ts) { /* * We set the minimum acceptable timestamp to PGSTAT_STAT_INTERVAL * msec before now. This indirectly ensures that the collector * needn't write the file more often than PGSTAT_STAT_INTERVAL. In * an autovacuum worker, however, we want a lower delay to avoid * using stale data, so we use PGSTAT_RETRY_DELAY (since the * number of workers is low, this shouldn't be a problem). * * We don't recompute min_ts after sleeping, except in the * unlikely case that cur_ts went backwards. So we might end up * accepting a file a bit older than PGSTAT_STAT_INTERVAL. In * practice that shouldn't happen, though, as long as the sleep * time is less than PGSTAT_STAT_INTERVAL; and we don't want to * tell the collector that our cutoff time is less than what we'd * actually accept. */ ref_ts = cur_ts; if (IsAutoVacuumWorkerProcess()) min_ts = TimestampTzPlusMilliseconds(ref_ts, -PGSTAT_RETRY_DELAY); else min_ts = TimestampTzPlusMilliseconds(ref_ts, -PGSTAT_STAT_INTERVAL); } /* * If the file timestamp is actually newer than cur_ts, we must have * had a clock glitch (system time went backwards) or there is clock * skew between our processor and the stats collector's processor. * Accept the file, but send an inquiry message anyway to make * pgstat_recv_inquiry do a sanity check on the collector's time. */ if (ok && file_ts > cur_ts) { /* * A small amount of clock skew between processors isn't terribly * surprising, but a large difference is worth logging. We * arbitrarily define "large" as 1000 msec. */ if (file_ts >= TimestampTzPlusMilliseconds(cur_ts, 1000)) { char *filetime; char *mytime; /* Copy because timestamptz_to_str returns a static buffer */ filetime = pstrdup(timestamptz_to_str(file_ts)); mytime = pstrdup(timestamptz_to_str(cur_ts)); ereport(LOG, (errmsg("statistics collector's time %s is later than backend local time %s", filetime, mytime))); pfree(filetime); pfree(mytime); } pgstat_send_inquiry(cur_ts, min_ts, inquiry_db); break; } /* Normal acceptance case: file is not older than cutoff time */ if (ok && file_ts >= min_ts) break; /* Not there or too old, so kick the collector and wait a bit */ if ((count % PGSTAT_INQ_LOOP_COUNT) == 0) pgstat_send_inquiry(cur_ts, min_ts, inquiry_db); pg_usleep(PGSTAT_RETRY_DELAY * 1000L); } if (count >= PGSTAT_POLL_LOOP_COUNT) ereport(LOG, (errmsg("using stale statistics instead of current ones " "because stats collector is not responding"))); /* * Autovacuum launcher wants stats about all databases, but a shallow read * is sufficient. Regular backends want a deep read for just the tables * they can see (MyDatabaseId + shared catalogs). */ if (IsAutoVacuumLauncherProcess()) pgStatDBHash = pgstat_read_statsfiles(InvalidOid, false, false); else pgStatDBHash = pgstat_read_statsfiles(MyDatabaseId, false, true); } /* ---------- * pgstat_setup_memcxt() - * * Create pgStatLocalContext, if not already done. * ---------- */ static void pgstat_setup_memcxt(void) { if (!pgStatLocalContext) pgStatLocalContext = AllocSetContextCreate(TopMemoryContext, "Statistics snapshot", ALLOCSET_SMALL_SIZES); } /* * Stats should only be reported after pgstat_initialize() and before * pgstat_shutdown(). This check is put in a few central places to catch * violations of this rule more easily. */ #ifdef USE_ASSERT_CHECKING void pgstat_assert_is_up(void) { Assert(pgstat_is_initialized && !pgstat_is_shutdown); } #endif /* ---------- * 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) { pgstat_assert_is_up(); /* Release memory, if any was allocated */ if (pgStatLocalContext) MemoryContextDelete(pgStatLocalContext); /* Reset variables */ pgStatLocalContext = NULL; pgStatDBHash = NULL; replSlotStatHash = NULL; subscriptionStatHash = NULL; /* * Historically the backend_status.c facilities lived in this file, and * were reset with the same function. For now keep it that way, and * forward the reset request. */ pgstat_clear_backend_activity_snapshot(); } /* ---------- * pgstat_recv_inquiry() - * * Process stat inquiry requests. * ---------- */ static void pgstat_recv_inquiry(PgStat_MsgInquiry *msg, int len) { PgStat_StatDBEntry *dbentry; elog(DEBUG2, "received inquiry for database %u", msg->databaseid); /* * If there's already a write request for this DB, there's nothing to do. * * Note that if a request is found, we return early and skip the below * check for clock skew. This is okay, since the only way for a DB * request to be present in the list is that we have been here since the * last write round. It seems sufficient to check for clock skew once per * write round. */ if (list_member_oid(pending_write_requests, msg->databaseid)) return; /* * Check to see if we last wrote this database at a time >= the requested * cutoff time. If so, this is a stale request that was generated before * we updated the DB file, and we don't need to do so again. * * If the requestor's local clock time is older than stats_timestamp, we * should suspect a clock glitch, ie system time going backwards; though * the more likely explanation is just delayed message receipt. It is * worth expending a GetCurrentTimestamp call to be sure, since a large * retreat in the system clock reading could otherwise cause us to neglect * to update the stats file for a long time. */ dbentry = pgstat_get_db_entry(msg->databaseid, false); if (dbentry == NULL) { /* * We have no data for this DB. Enter a write request anyway so that * the global stats will get updated. This is needed to prevent * backend_read_statsfile from waiting for data that we cannot supply, * in the case of a new DB that nobody has yet reported any stats for. * See the behavior of pgstat_read_db_statsfile_timestamp. */ } else if (msg->clock_time < dbentry->stats_timestamp) { TimestampTz cur_ts = GetCurrentTimestamp(); if (cur_ts < dbentry->stats_timestamp) { /* * Sure enough, time went backwards. Force a new stats file write * to get back in sync; but first, log a complaint. */ char *writetime; char *mytime; /* Copy because timestamptz_to_str returns a static buffer */ writetime = pstrdup(timestamptz_to_str(dbentry->stats_timestamp)); mytime = pstrdup(timestamptz_to_str(cur_ts)); ereport(LOG, (errmsg("stats_timestamp %s is later than collector's time %s for database %u", writetime, mytime, dbentry->databaseid))); pfree(writetime); pfree(mytime); } else { /* * Nope, it's just an old request. Assuming msg's clock_time is * >= its cutoff_time, it must be stale, so we can ignore it. */ return; } } else if (msg->cutoff_time <= dbentry->stats_timestamp) { /* Stale request, ignore it */ return; } /* * We need to write this DB, so create a request. */ pending_write_requests = lappend_oid(pending_write_requests, msg->databaseid); } /* ---------- * pgstat_recv_tabstat() - * * Count what the backend has done. * ---------- */ static void pgstat_recv_tabstat(PgStat_MsgTabstat *msg, int len) { 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); dbentry->n_block_read_time += msg->m_block_read_time; dbentry->n_block_write_time += msg->m_block_write_time; dbentry->total_session_time += msg->m_session_time; dbentry->total_active_time += msg->m_active_time; dbentry->total_idle_in_xact_time += msg->m_idle_in_xact_time; /* * Process all table entries in the message. */ for (i = 0; i < msg->m_nentries; i++) { PgStat_TableEntry *tabmsg = &(msg->m_entry[i]); tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables, (void *) &(tabmsg->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->t_counts.t_numscans; tabentry->tuples_returned = tabmsg->t_counts.t_tuples_returned; tabentry->tuples_fetched = tabmsg->t_counts.t_tuples_fetched; tabentry->tuples_inserted = tabmsg->t_counts.t_tuples_inserted; tabentry->tuples_updated = tabmsg->t_counts.t_tuples_updated; tabentry->tuples_deleted = tabmsg->t_counts.t_tuples_deleted; tabentry->tuples_hot_updated = tabmsg->t_counts.t_tuples_hot_updated; tabentry->n_live_tuples = tabmsg->t_counts.t_delta_live_tuples; tabentry->n_dead_tuples = tabmsg->t_counts.t_delta_dead_tuples; tabentry->changes_since_analyze = tabmsg->t_counts.t_changed_tuples; tabentry->inserts_since_vacuum = tabmsg->t_counts.t_tuples_inserted; tabentry->blocks_fetched = tabmsg->t_counts.t_blocks_fetched; tabentry->blocks_hit = tabmsg->t_counts.t_blocks_hit; tabentry->vacuum_timestamp = 0; tabentry->vacuum_count = 0; tabentry->autovac_vacuum_timestamp = 0; tabentry->autovac_vacuum_count = 0; tabentry->analyze_timestamp = 0; tabentry->analyze_count = 0; tabentry->autovac_analyze_timestamp = 0; tabentry->autovac_analyze_count = 0; } else { /* * Otherwise add the values to the existing entry. */ tabentry->numscans += tabmsg->t_counts.t_numscans; tabentry->tuples_returned += tabmsg->t_counts.t_tuples_returned; tabentry->tuples_fetched += tabmsg->t_counts.t_tuples_fetched; tabentry->tuples_inserted += tabmsg->t_counts.t_tuples_inserted; tabentry->tuples_updated += tabmsg->t_counts.t_tuples_updated; tabentry->tuples_deleted += tabmsg->t_counts.t_tuples_deleted; tabentry->tuples_hot_updated += tabmsg->t_counts.t_tuples_hot_updated; /* * If table was truncated/dropped, first reset the live/dead * counters. */ if (tabmsg->t_counts.t_truncdropped) { tabentry->n_live_tuples = 0; tabentry->n_dead_tuples = 0; tabentry->inserts_since_vacuum = 0; } tabentry->n_live_tuples += tabmsg->t_counts.t_delta_live_tuples; tabentry->n_dead_tuples += tabmsg->t_counts.t_delta_dead_tuples; tabentry->changes_since_analyze += tabmsg->t_counts.t_changed_tuples; tabentry->inserts_since_vacuum += tabmsg->t_counts.t_tuples_inserted; tabentry->blocks_fetched += tabmsg->t_counts.t_blocks_fetched; tabentry->blocks_hit += tabmsg->t_counts.t_blocks_hit; } /* Clamp n_live_tuples in case of negative delta_live_tuples */ tabentry->n_live_tuples = Max(tabentry->n_live_tuples, 0); /* Likewise for n_dead_tuples */ tabentry->n_dead_tuples = Max(tabentry->n_dead_tuples, 0); /* * Add per-table stats to the per-database entry, too. */ dbentry->n_tuples_returned += tabmsg->t_counts.t_tuples_returned; dbentry->n_tuples_fetched += tabmsg->t_counts.t_tuples_fetched; dbentry->n_tuples_inserted += tabmsg->t_counts.t_tuples_inserted; dbentry->n_tuples_updated += tabmsg->t_counts.t_tuples_updated; dbentry->n_tuples_deleted += tabmsg->t_counts.t_tuples_deleted; dbentry->n_blocks_fetched += tabmsg->t_counts.t_blocks_fetched; dbentry->n_blocks_hit += tabmsg->t_counts.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) { Oid dbid = msg->m_databaseid; PgStat_StatDBEntry *dbentry; /* * Lookup the database in the hashtable. */ dbentry = pgstat_get_db_entry(dbid, false); /* * If found, remove it (along with the db statfile). */ if (dbentry) { char statfile[MAXPGPATH]; get_dbstat_filename(false, false, dbid, statfile, MAXPGPATH); elog(DEBUG2, "removing stats file \"%s\"", statfile); unlink(statfile); if (dbentry->tables != NULL) hash_destroy(dbentry->tables); if (dbentry->functions != NULL) hash_destroy(dbentry->functions); if (hash_search(pgStatDBHash, (void *) &dbid, 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) { 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); if (dbentry->functions != NULL) hash_destroy(dbentry->functions); dbentry->tables = NULL; dbentry->functions = NULL; /* * Reset database-level stats, too. This creates empty hash tables for * tables and functions. */ reset_dbentry_counters(dbentry); } /* ---------- * pgstat_recv_resetsharedcounter() - * * Reset some shared statistics of the cluster. * ---------- */ static void pgstat_recv_resetsharedcounter(PgStat_MsgResetsharedcounter *msg, int len) { if (msg->m_resettarget == RESET_BGWRITER) { /* * Reset the global, bgwriter and checkpointer statistics for the * cluster. */ memset(&globalStats, 0, sizeof(globalStats)); globalStats.bgwriter.stat_reset_timestamp = GetCurrentTimestamp(); } else if (msg->m_resettarget == RESET_ARCHIVER) { /* Reset the archiver statistics for the cluster. */ memset(&archiverStats, 0, sizeof(archiverStats)); archiverStats.stat_reset_timestamp = GetCurrentTimestamp(); } else if (msg->m_resettarget == RESET_WAL) { /* Reset the WAL statistics for the cluster. */ memset(&walStats, 0, sizeof(walStats)); walStats.stat_reset_timestamp = GetCurrentTimestamp(); } /* * Presumably the sender of this message validated the target, don't * complain here if it's not valid */ } /* ---------- * pgstat_recv_resetsinglecounter() - * * Reset a statistics for a single object, which may be of current * database or shared across all databases in the cluster. * ---------- */ static void pgstat_recv_resetsinglecounter(PgStat_MsgResetsinglecounter *msg, int len) { PgStat_StatDBEntry *dbentry; if (IsSharedRelation(msg->m_objectid)) dbentry = pgstat_get_db_entry(InvalidOid, false); else dbentry = pgstat_get_db_entry(msg->m_databaseid, false); if (!dbentry) return; /* Set the reset timestamp for the whole database */ dbentry->stat_reset_timestamp = GetCurrentTimestamp(); /* Remove object if it exists, ignore it if not */ if (msg->m_resettype == RESET_TABLE) (void) hash_search(dbentry->tables, (void *) &(msg->m_objectid), HASH_REMOVE, NULL); else if (msg->m_resettype == RESET_FUNCTION) (void) hash_search(dbentry->functions, (void *) &(msg->m_objectid), HASH_REMOVE, NULL); } /* ---------- * pgstat_recv_resetslrucounter() - * * Reset some SLRU statistics of the cluster. * ---------- */ static void pgstat_recv_resetslrucounter(PgStat_MsgResetslrucounter *msg, int len) { int i; TimestampTz ts = GetCurrentTimestamp(); for (i = 0; i < SLRU_NUM_ELEMENTS; i++) { /* reset entry with the given index, or all entries (index is -1) */ if ((msg->m_index == -1) || (msg->m_index == i)) { memset(&slruStats[i], 0, sizeof(slruStats[i])); slruStats[i].stat_reset_timestamp = ts; } } } /* ---------- * pgstat_recv_resetreplslotcounter() - * * Reset some replication slot statistics of the cluster. * ---------- */ static void pgstat_recv_resetreplslotcounter(PgStat_MsgResetreplslotcounter *msg, int len) { PgStat_StatReplSlotEntry *slotent; TimestampTz ts; /* Return if we don't have replication slot statistics */ if (replSlotStatHash == NULL) return; ts = GetCurrentTimestamp(); if (msg->clearall) { HASH_SEQ_STATUS sstat; hash_seq_init(&sstat, replSlotStatHash); while ((slotent = (PgStat_StatReplSlotEntry *) hash_seq_search(&sstat)) != NULL) pgstat_reset_replslot(slotent, ts); } else { /* Get the slot statistics to reset */ slotent = pgstat_get_replslot_entry(msg->m_slotname, false); /* * Nothing to do if the given slot entry is not found. This could * happen when the slot with the given name is removed and the * corresponding statistics entry is also removed before receiving the * reset message. */ if (!slotent) return; /* Reset the stats for the requested replication slot */ pgstat_reset_replslot(slotent, ts); } } /* ---------- * pgstat_recv_resetsubcounter() - * * Reset some subscription statistics of the cluster. * ---------- */ static void pgstat_recv_resetsubcounter(PgStat_MsgResetsubcounter *msg, int len) { PgStat_StatSubEntry *subentry; TimestampTz ts; /* Return if we don't have replication subscription statistics */ if (subscriptionStatHash == NULL) return; ts = GetCurrentTimestamp(); if (!OidIsValid(msg->m_subid)) { HASH_SEQ_STATUS sstat; /* Clear all subscription counters */ hash_seq_init(&sstat, subscriptionStatHash); while ((subentry = (PgStat_StatSubEntry *) hash_seq_search(&sstat)) != NULL) pgstat_reset_subscription(subentry, ts); } else { /* Get the subscription statistics to reset */ subentry = pgstat_get_subscription_entry(msg->m_subid, false); /* * Nothing to do if the given subscription entry is not found. This * could happen when the subscription with the subid is removed and * the corresponding statistics entry is also removed before receiving * the reset message. */ if (!subentry) return; /* Reset the stats for the requested subscription */ pgstat_reset_subscription(subentry, ts); } } /* ---------- * pgstat_recv_autovac() - * * Process an autovacuum signaling message. * ---------- */ static void pgstat_recv_autovac(PgStat_MsgAutovacStart *msg, int len) { PgStat_StatDBEntry *dbentry; /* * Store the last autovacuum time in the database's hashtable entry. */ dbentry = pgstat_get_db_entry(msg->m_databaseid, true); 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; /* * Store the data in the table's hashtable entry. */ dbentry = pgstat_get_db_entry(msg->m_databaseid, true); tabentry = pgstat_get_tab_entry(dbentry, msg->m_tableoid, true); tabentry->n_live_tuples = msg->m_live_tuples; tabentry->n_dead_tuples = msg->m_dead_tuples; /* * It is quite possible that a non-aggressive VACUUM ended up skipping * various pages, however, we'll zero the insert counter here regardless. * It's currently used only to track when we need to perform an "insert" * autovacuum, which are mainly intended to freeze newly inserted tuples. * Zeroing this may just mean we'll not try to vacuum the table again * until enough tuples have been inserted to trigger another insert * autovacuum. An anti-wraparound autovacuum will catch any persistent * stragglers. */ tabentry->inserts_since_vacuum = 0; if (msg->m_autovacuum) { tabentry->autovac_vacuum_timestamp = msg->m_vacuumtime; tabentry->autovac_vacuum_count++; } else { tabentry->vacuum_timestamp = msg->m_vacuumtime; tabentry->vacuum_count++; } } /* ---------- * pgstat_recv_analyze() - * * Process an ANALYZE message. * ---------- */ static void pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len) { PgStat_StatDBEntry *dbentry; PgStat_StatTabEntry *tabentry; /* * Store the data in the table's hashtable entry. */ dbentry = pgstat_get_db_entry(msg->m_databaseid, true); tabentry = pgstat_get_tab_entry(dbentry, msg->m_tableoid, true); tabentry->n_live_tuples = msg->m_live_tuples; tabentry->n_dead_tuples = msg->m_dead_tuples; /* * If commanded, reset changes_since_analyze to zero. This forgets any * changes that were committed while the ANALYZE was in progress, but we * have no good way to estimate how many of those there were. */ if (msg->m_resetcounter) tabentry->changes_since_analyze = 0; if (msg->m_autovacuum) { tabentry->autovac_analyze_timestamp = msg->m_analyzetime; tabentry->autovac_analyze_count++; } else { tabentry->analyze_timestamp = msg->m_analyzetime; tabentry->analyze_count++; } } /* ---------- * pgstat_recv_archiver() - * * Process a ARCHIVER message. * ---------- */ static void pgstat_recv_archiver(PgStat_MsgArchiver *msg, int len) { if (msg->m_failed) { /* Failed archival attempt */ ++archiverStats.failed_count; memcpy(archiverStats.last_failed_wal, msg->m_xlog, sizeof(archiverStats.last_failed_wal)); archiverStats.last_failed_timestamp = msg->m_timestamp; } else { /* Successful archival operation */ ++archiverStats.archived_count; memcpy(archiverStats.last_archived_wal, msg->m_xlog, sizeof(archiverStats.last_archived_wal)); archiverStats.last_archived_timestamp = msg->m_timestamp; } } /* ---------- * pgstat_recv_bgwriter() - * * Process a BGWRITER message. * ---------- */ static void pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len) { globalStats.bgwriter.buf_written_clean += msg->m_buf_written_clean; globalStats.bgwriter.maxwritten_clean += msg->m_maxwritten_clean; globalStats.bgwriter.buf_alloc += msg->m_buf_alloc; } /* ---------- * pgstat_recv_checkpointer() - * * Process a CHECKPOINTER message. * ---------- */ static void pgstat_recv_checkpointer(PgStat_MsgCheckpointer *msg, int len) { globalStats.checkpointer.timed_checkpoints += msg->m_timed_checkpoints; globalStats.checkpointer.requested_checkpoints += msg->m_requested_checkpoints; globalStats.checkpointer.checkpoint_write_time += msg->m_checkpoint_write_time; globalStats.checkpointer.checkpoint_sync_time += msg->m_checkpoint_sync_time; globalStats.checkpointer.buf_written_checkpoints += msg->m_buf_written_checkpoints; globalStats.checkpointer.buf_written_backend += msg->m_buf_written_backend; globalStats.checkpointer.buf_fsync_backend += msg->m_buf_fsync_backend; } /* ---------- * pgstat_recv_wal() - * * Process a WAL message. * ---------- */ static void pgstat_recv_wal(PgStat_MsgWal *msg, int len) { walStats.wal_records += msg->m_wal_records; walStats.wal_fpi += msg->m_wal_fpi; walStats.wal_bytes += msg->m_wal_bytes; walStats.wal_buffers_full += msg->m_wal_buffers_full; walStats.wal_write += msg->m_wal_write; walStats.wal_sync += msg->m_wal_sync; walStats.wal_write_time += msg->m_wal_write_time; walStats.wal_sync_time += msg->m_wal_sync_time; } /* ---------- * pgstat_recv_slru() - * * Process a SLRU message. * ---------- */ static void pgstat_recv_slru(PgStat_MsgSLRU *msg, int len) { slruStats[msg->m_index].blocks_zeroed += msg->m_blocks_zeroed; slruStats[msg->m_index].blocks_hit += msg->m_blocks_hit; slruStats[msg->m_index].blocks_read += msg->m_blocks_read; slruStats[msg->m_index].blocks_written += msg->m_blocks_written; slruStats[msg->m_index].blocks_exists += msg->m_blocks_exists; slruStats[msg->m_index].flush += msg->m_flush; slruStats[msg->m_index].truncate += msg->m_truncate; } /* ---------- * pgstat_recv_recoveryconflict() - * * Process a RECOVERYCONFLICT message. * ---------- */ static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len) { PgStat_StatDBEntry *dbentry; dbentry = pgstat_get_db_entry(msg->m_databaseid, true); switch (msg->m_reason) { case PROCSIG_RECOVERY_CONFLICT_DATABASE: /* * Since we drop the information about the database as soon as it * replicates, there is no point in counting these conflicts. */ break; case PROCSIG_RECOVERY_CONFLICT_TABLESPACE: dbentry->n_conflict_tablespace++; break; case PROCSIG_RECOVERY_CONFLICT_LOCK: dbentry->n_conflict_lock++; break; case PROCSIG_RECOVERY_CONFLICT_SNAPSHOT: dbentry->n_conflict_snapshot++; break; case PROCSIG_RECOVERY_CONFLICT_BUFFERPIN: dbentry->n_conflict_bufferpin++; break; case PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK: dbentry->n_conflict_startup_deadlock++; break; } } /* ---------- * pgstat_recv_deadlock() - * * Process a DEADLOCK message. * ---------- */ static void pgstat_recv_deadlock(PgStat_MsgDeadlock *msg, int len) { PgStat_StatDBEntry *dbentry; dbentry = pgstat_get_db_entry(msg->m_databaseid, true); dbentry->n_deadlocks++; } /* ---------- * pgstat_recv_checksum_failure() - * * Process a CHECKSUMFAILURE message. * ---------- */ static void pgstat_recv_checksum_failure(PgStat_MsgChecksumFailure *msg, int len) { PgStat_StatDBEntry *dbentry; dbentry = pgstat_get_db_entry(msg->m_databaseid, true); dbentry->n_checksum_failures += msg->m_failurecount; dbentry->last_checksum_failure = msg->m_failure_time; } /* ---------- * pgstat_recv_replslot() - * * Process a REPLSLOT message. * ---------- */ static void pgstat_recv_replslot(PgStat_MsgReplSlot *msg, int len) { if (msg->m_drop) { Assert(!msg->m_create); /* Remove the replication slot statistics with the given name */ if (replSlotStatHash != NULL) (void) hash_search(replSlotStatHash, (void *) &(msg->m_slotname), HASH_REMOVE, NULL); } else { PgStat_StatReplSlotEntry *slotent; slotent = pgstat_get_replslot_entry(msg->m_slotname, true); Assert(slotent); if (msg->m_create) { /* * If the message for dropping the slot with the same name gets * lost, slotent has stats for the old slot. So we initialize all * counters at slot creation. */ pgstat_reset_replslot(slotent, 0); } else { /* Update the replication slot statistics */ slotent->spill_txns += msg->m_spill_txns; slotent->spill_count += msg->m_spill_count; slotent->spill_bytes += msg->m_spill_bytes; slotent->stream_txns += msg->m_stream_txns; slotent->stream_count += msg->m_stream_count; slotent->stream_bytes += msg->m_stream_bytes; slotent->total_txns += msg->m_total_txns; slotent->total_bytes += msg->m_total_bytes; } } } /* ---------- * pgstat_recv_connect() - * * Process a CONNECT message. * ---------- */ static void pgstat_recv_connect(PgStat_MsgConnect *msg, int len) { PgStat_StatDBEntry *dbentry; dbentry = pgstat_get_db_entry(msg->m_databaseid, true); dbentry->n_sessions++; } /* ---------- * pgstat_recv_disconnect() - * * Process a DISCONNECT message. * ---------- */ static void pgstat_recv_disconnect(PgStat_MsgDisconnect *msg, int len) { PgStat_StatDBEntry *dbentry; dbentry = pgstat_get_db_entry(msg->m_databaseid, true); switch (msg->m_cause) { case DISCONNECT_NOT_YET: case DISCONNECT_NORMAL: /* we don't collect these */ break; case DISCONNECT_CLIENT_EOF: dbentry->n_sessions_abandoned++; break; case DISCONNECT_FATAL: dbentry->n_sessions_fatal++; break; case DISCONNECT_KILLED: dbentry->n_sessions_killed++; break; } } /* ---------- * pgstat_recv_tempfile() - * * Process a TEMPFILE message. * ---------- */ static void pgstat_recv_tempfile(PgStat_MsgTempFile *msg, int len) { PgStat_StatDBEntry *dbentry; dbentry = pgstat_get_db_entry(msg->m_databaseid, true); dbentry->n_temp_bytes += msg->m_filesize; dbentry->n_temp_files += 1; } /* ---------- * pgstat_recv_funcstat() - * * Count what the backend has done. * ---------- */ static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len) { PgStat_FunctionEntry *funcmsg = &(msg->m_entry[0]); PgStat_StatDBEntry *dbentry; PgStat_StatFuncEntry *funcentry; int i; bool found; dbentry = pgstat_get_db_entry(msg->m_databaseid, true); /* * Process all function entries in the message. */ for (i = 0; i < msg->m_nentries; i++, funcmsg++) { funcentry = (PgStat_StatFuncEntry *) hash_search(dbentry->functions, (void *) &(funcmsg->f_id), HASH_ENTER, &found); if (!found) { /* * If it's a new function entry, initialize counters to the values * we just got. */ funcentry->f_numcalls = funcmsg->f_numcalls; funcentry->f_total_time = funcmsg->f_total_time; funcentry->f_self_time = funcmsg->f_self_time; } else { /* * Otherwise add the values to the existing entry. */ funcentry->f_numcalls += funcmsg->f_numcalls; funcentry->f_total_time += funcmsg->f_total_time; funcentry->f_self_time += funcmsg->f_self_time; } } } /* ---------- * pgstat_recv_funcpurge() - * * Arrange for dead function removal. * ---------- */ static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *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->functions) return; /* * Process all function 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->functions, (void *) &(msg->m_functionid[i]), HASH_REMOVE, NULL); } } /* ---------- * pgstat_recv_subscription_drop() - * * Process a SUBSCRIPTIONDROP message. * ---------- */ static void pgstat_recv_subscription_drop(PgStat_MsgSubscriptionDrop *msg, int len) { /* Return if we don't have replication subscription statistics */ if (subscriptionStatHash == NULL) return; /* Remove from hashtable if present; we don't care if it's not */ (void) hash_search(subscriptionStatHash, (void *) &(msg->m_subid), HASH_REMOVE, NULL); } /* ---------- * pgstat_recv_subscription_error() - * * Process a SUBSCRIPTIONERROR message. * ---------- */ static void pgstat_recv_subscription_error(PgStat_MsgSubscriptionError *msg, int len) { PgStat_StatSubEntry *subentry; /* Get the subscription stats */ subentry = pgstat_get_subscription_entry(msg->m_subid, true); Assert(subentry); if (msg->m_is_apply_error) subentry->apply_error_count++; else subentry->sync_error_count++; } /* ---------- * pgstat_write_statsfile_needed() - * * Do we need to write out any stats files? * ---------- */ static bool pgstat_write_statsfile_needed(void) { if (pending_write_requests != NIL) return true; /* Everything was written recently */ return false; } /* ---------- * pgstat_db_requested() - * * Checks whether stats for a particular DB need to be written to a file. * ---------- */ static bool pgstat_db_requested(Oid databaseid) { /* * If any requests are outstanding at all, we should write the stats for * shared catalogs (the "database" with OID 0). This ensures that * backends will see up-to-date stats for shared catalogs, even though * they send inquiry messages mentioning only their own DB. */ if (databaseid == InvalidOid && pending_write_requests != NIL) return true; /* Search to see if there's an open request to write this database. */ if (list_member_oid(pending_write_requests, databaseid)) return true; return false; } /* ---------- * pgstat_replslot_entry * * Return the entry of replication slot stats with the given name. Return * NULL if not found and the caller didn't request to create it. * * create tells whether to create the new slot entry if it is not found. * ---------- */ static PgStat_StatReplSlotEntry * pgstat_get_replslot_entry(NameData name, bool create) { PgStat_StatReplSlotEntry *slotent; bool found; if (replSlotStatHash == NULL) { HASHCTL hash_ctl; /* * Quick return NULL if the hash table is empty and the caller didn't * request to create the entry. */ if (!create) return NULL; hash_ctl.keysize = sizeof(NameData); hash_ctl.entrysize = sizeof(PgStat_StatReplSlotEntry); replSlotStatHash = hash_create("Replication slots hash", PGSTAT_REPLSLOT_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_BLOBS); } slotent = (PgStat_StatReplSlotEntry *) hash_search(replSlotStatHash, (void *) &name, create ? HASH_ENTER : HASH_FIND, &found); if (!slotent) { /* not found */ Assert(!create && !found); return NULL; } /* initialize the entry */ if (create && !found) { namestrcpy(&(slotent->slotname), NameStr(name)); pgstat_reset_replslot(slotent, 0); } return slotent; } /* ---------- * pgstat_reset_replslot * * Reset the given replication slot stats. * ---------- */ static void pgstat_reset_replslot(PgStat_StatReplSlotEntry *slotent, TimestampTz ts) { /* reset only counters. Don't clear slot name */ slotent->spill_txns = 0; slotent->spill_count = 0; slotent->spill_bytes = 0; slotent->stream_txns = 0; slotent->stream_count = 0; slotent->stream_bytes = 0; slotent->total_txns = 0; slotent->total_bytes = 0; slotent->stat_reset_timestamp = ts; } /* ---------- * pgstat_get_subscription_entry * * Return the subscription statistics entry with the given subscription OID. * If no subscription entry exists, initialize it, if the create parameter is * true. Else, return NULL. * ---------- */ static PgStat_StatSubEntry * pgstat_get_subscription_entry(Oid subid, bool create) { PgStat_StatSubEntry *subentry; bool found; HASHACTION action = (create ? HASH_ENTER : HASH_FIND); if (subscriptionStatHash == NULL) { HASHCTL hash_ctl; /* * Quick return NULL if the hash table is empty and the caller didn't * request to create the entry. */ if (!create) return NULL; hash_ctl.keysize = sizeof(Oid); hash_ctl.entrysize = sizeof(PgStat_StatSubEntry); subscriptionStatHash = hash_create("Subscription hash", PGSTAT_SUBSCRIPTION_HASH_SIZE, &hash_ctl, HASH_ELEM | HASH_BLOBS); } subentry = (PgStat_StatSubEntry *) hash_search(subscriptionStatHash, (void *) &subid, action, &found); if (!create && !found) return NULL; /* If not found, initialize the new one */ if (!found) pgstat_reset_subscription(subentry, 0); return subentry; } /* ---------- * pgstat_reset_subscription * * Reset the given subscription stats. * ---------- */ static void pgstat_reset_subscription(PgStat_StatSubEntry *subentry, TimestampTz ts) { subentry->apply_error_count = 0; subentry->sync_error_count = 0; subentry->stat_reset_timestamp = ts; }