diff options
Diffstat (limited to 'src/backend/postmaster/pgstat.c')
| -rw-r--r-- | src/backend/postmaster/pgstat.c | 2715 |
1 files changed, 0 insertions, 2715 deletions
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c deleted file mode 100644 index b578305b4c5..00000000000 --- a/src/backend/postmaster/pgstat.c +++ /dev/null @@ -1,2715 +0,0 @@ -/* ---------- - * 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 base. - * Not to be done before 7.2 - requires catalog change and - * thus an initdb and we might want to provide this as a - * patch for 7.1. - * - * Copyright (c) 2001, PostgreSQL Global Development Group - * - * $Header: /cvsroot/pgsql/src/backend/postmaster/pgstat.c,v 1.21 2002/05/20 23:51:43 tgl Exp $ - * ---------- - */ -#include "postgres.h" - -#include <unistd.h> -#include <fcntl.h> -#include <sys/param.h> -#include <sys/time.h> -#include <sys/types.h> -#include <sys/socket.h> -#include <netinet/in.h> -#include <arpa/inet.h> -#include <errno.h> -#include <signal.h> - -#include "access/xact.h" -#include "access/heapam.h" -#include "catalog/catname.h" -#include "catalog/pg_shadow.h" -#include "catalog/pg_database.h" -#include "libpq/pqsignal.h" -#ifdef MULTIBYTE -#include "mb/pg_wchar.h" -#endif -#include "miscadmin.h" -#include "utils/memutils.h" -#include "storage/backendid.h" -#include "storage/ipc.h" -#include "utils/rel.h" -#include "utils/hsearch.h" -#include "utils/ps_status.h" -#include "utils/syscache.h" - -#include "pgstat.h" - - -/* ---------- - * GUC parameters - * ---------- - */ -bool pgstat_collect_startcollector = true; -bool pgstat_collect_resetonpmstart = true; -bool pgstat_collect_querystring = false; -bool pgstat_collect_tuplelevel = false; -bool pgstat_collect_blocklevel = false; - -/* ---------- - * Local data - * ---------- - */ -static int pgStatSock = -1; -static int pgStatPipe[2]; -static struct sockaddr_in pgStatAddr; -static int pgStatPmPipe[2] = {-1, -1}; - -static int pgStatRunning = 0; -static int pgStatPid; - -static long pgStatNumMessages = 0; - -static bool pgStatRunningInCollector = FALSE; -static int pgStatTabstatAlloc = 0; -static int pgStatTabstatUsed = 0; -static PgStat_MsgTabstat **pgStatTabstatMessages = NULL; -static int pgStatXactCommit = 0; -static int pgStatXactRollback = 0; - - -static TransactionId pgStatDBHashXact = InvalidTransactionId; -static HTAB *pgStatDBHash = NULL; -static HTAB *pgStatBeDead = NULL; -static PgStat_StatBeEntry *pgStatBeTable = NULL; -static int pgStatNumBackends = 0; - -static char pgStat_tmpfname[MAXPGPATH]; -static char pgStat_fname[MAXPGPATH]; - - -/* ---------- - * Local function forward declarations - * ---------- - */ -static void pgstat_main(void); -static void pgstat_recvbuffer(void); -static void pgstat_die(SIGNAL_ARGS); - -static int pgstat_add_backend(PgStat_MsgHdr *msg); -static void pgstat_sub_backend(int procpid); -static void pgstat_drop_database(Oid databaseid); -static void pgstat_write_statsfile(void); -static void pgstat_read_statsfile(HTAB **dbhash, Oid onlydb, - PgStat_StatBeEntry **betab, - int *numbackends); - -static void pgstat_setheader(PgStat_MsgHdr *hdr, int mtype); -static void pgstat_send(void *msg, int len); - -static void pgstat_recv_bestart(PgStat_MsgBestart *msg, int len); -static void pgstat_recv_beterm(PgStat_MsgBeterm *msg, int len); -static void pgstat_recv_activity(PgStat_MsgActivity *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); - - -/* ------------------------------------------------------------ - * Public functions called from postmaster follow - * ------------------------------------------------------------ - */ - - -/* ---------- - * pgstat_init() - - * - * Called from postmaster at startup. Create the resources required - * by the statistics collector process. - * - * NOTE: failure exit from this routine causes the postmaster to abort. - * This is unfriendly and should not be done except in dire straits. - * Better to let the postmaster start with stats collection disabled. - * ---------- - */ -int -pgstat_init(void) -{ - int alen; - - /* - * Force start of collector daemon if something to collect - */ - if (pgstat_collect_querystring || pgstat_collect_tuplelevel || - pgstat_collect_blocklevel) - pgstat_collect_startcollector = true; - - /* - * Initialize the filenames for the status reports. - */ - snprintf(pgStat_tmpfname, MAXPGPATH, - PGSTAT_STAT_TMPFILE, DataDir, getpid()); - snprintf(pgStat_fname, MAXPGPATH, - PGSTAT_STAT_FILENAME, DataDir); - - /* - * If we don't have to start a collector or should reset the collected - * statistics on postmaster start, simply remove the file. - */ - if (!pgstat_collect_startcollector || pgstat_collect_resetonpmstart) - unlink(pgStat_fname); - - /* - * Nothing else required if collector will not get started - */ - if (!pgstat_collect_startcollector) - return 0; - - /* - * Create the UDP socket for sending and receiving statistic messages - */ - if ((pgStatSock = socket(PF_INET, SOCK_DGRAM, 0)) < 0) - { - elog(LOG, "PGSTAT: socket() failed: %m"); - goto startup_failed; - } - - /* - * Bind it to a kernel assigned port on localhost and get the assigned - * port via getsockname(). - */ - pgStatAddr.sin_family = AF_INET; - pgStatAddr.sin_port = htons(0); - inet_aton("127.0.0.1", &(pgStatAddr.sin_addr)); - alen = sizeof(pgStatAddr); - if (bind(pgStatSock, (struct sockaddr *) & pgStatAddr, alen) < 0) - { - elog(LOG, "PGSTAT: bind(127.0.0.1) failed: %m"); - goto startup_failed; - } - if (getsockname(pgStatSock, (struct sockaddr *) & pgStatAddr, &alen) < 0) - { - elog(LOG, "PGSTAT: getsockname() failed: %m"); - goto startup_failed; - } - - /* - * 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) - { - elog(LOG, "PGSTAT: connect() failed: %m"); - goto startup_failed; - } - - /* - * Set the socket to non-blocking IO. This ensures that if the - * collector falls behind (despite the buffering process), statistics - * messages will be discarded; backends won't block waiting to send - * messages to the collector. - */ - if (fcntl(pgStatSock, F_SETFL, O_NONBLOCK) < 0) - { - elog(LOG, "PGSTAT: fcntl() failed: %m"); - goto startup_failed; - } - - /* - * Create the pipe that controls the statistics collector shutdown - */ - if (pipe(pgStatPmPipe) < 0) - { - elog(LOG, "PGSTAT: pipe() failed: %m"); - goto startup_failed; - } - - return 0; - -startup_failed: - if (pgStatSock >= 0) - close(pgStatSock); - pgStatSock = -1; - - /* Adjust GUC variables to suppress useless activity */ - pgstat_collect_querystring = false; - pgstat_collect_tuplelevel = false; - pgstat_collect_blocklevel = false; - - return 0; -} - - -/* ---------- - * pgstat_start() - - * - * Called from postmaster at startup or after an existing collector - * died. Fire up a fresh statistics collector. - * - * NOTE: failure exit from this routine causes the postmaster to abort. - * ---------- - */ -int -pgstat_start(void) -{ - /* - * Do nothing if no collector needed - */ - if (!pgstat_collect_startcollector) - return 0; - - /* - * Check that the socket is there, else pgstat_init failed - */ - if (pgStatSock < 0) - { - elog(LOG, "PGSTAT: statistics collector startup skipped"); - return 0; - } - - /* - * Then fork off the collector. Remember its PID for pgstat_ispgstat. - */ - - fflush(stdout); - fflush(stderr); - -#ifdef __BEOS__ - /* Specific beos actions before backend startup */ - beos_before_backend_startup(); -#endif - - switch ((pgStatPid = (int) fork())) - { - case -1: -#ifdef __BEOS__ - /* Specific beos actions */ - beos_backend_startup_failed(); -#endif - elog(LOG, "PGSTAT: fork() failed: %m"); - pgStatRunning = 0; - return 0; - - case 0: - break; - - default: - pgStatRunning = 1; - return 0; - } - - /* in postmaster child ... */ - -#ifdef __BEOS__ - /* Specific beos actions after backend startup */ - beos_backend_startup(); -#endif - - IsUnderPostmaster = true; /* we are a postmaster subprocess now */ - - /* Lose the postmaster's on-exit routines */ - on_exit_reset(); - - /* Close the postmaster's sockets, except for pgstat link */ - ClosePostmasterPorts(false); - - pgstat_main(); - - exit(0); -} - - -/* ---------- - * pgstat_ispgstat() - - * - * Called from postmaster to check if a terminated child process - * was the statistics collector. - * ---------- - */ -int -pgstat_ispgstat(int pid) -{ - if (pgStatRunning == 0) - return 0; - - if (pgStatPid != pid) - return 0; - - return 1; -} - - -/* ---------- - * pgstat_close_sockets() - - * - * Called when postmaster forks a non-pgstat child process, to close off - * file descriptors that should not be held open in child processes. - * ---------- - */ -void -pgstat_close_sockets(void) -{ - if (pgStatPmPipe[0] >= 0) - close(pgStatPmPipe[0]); - pgStatPmPipe[0] = -1; - if (pgStatPmPipe[1] >= 0) - close(pgStatPmPipe[1]); - pgStatPmPipe[1] = -1; -} - - -/* ---------- - * pgstat_beterm() - - * - * Called from postmaster to tell collector a backend terminated. - * ---------- - */ -void -pgstat_beterm(int pid) -{ - PgStat_MsgBeterm msg; - - if (pgStatSock < 0) - return; - - msg.m_hdr.m_type = PGSTAT_MTYPE_BETERM; - msg.m_hdr.m_backendid = 0; - msg.m_hdr.m_procpid = pid; - msg.m_hdr.m_databaseid = 0; - - pgstat_send(&msg, sizeof(msg)); -} - - -/* ------------------------------------------------------------ - * Public functions used by backends follow - *------------------------------------------------------------ - */ - - -/* ---------- - * pgstat_bestart() - - * - * Tell the collector that this new backend is soon ready to process - * queries. Called from tcop/postgres.c before entering the mainloop. - * ---------- - */ -void -pgstat_bestart(void) -{ - PgStat_MsgBestart msg; - - if (pgStatSock < 0) - return; - - pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_BESTART); - pgstat_send(&msg, sizeof(msg)); -} - - -/* ---------- - * pgstat_report_activity() - - * - * Called in tcop/postgres.c to tell the collector what the backend - * is actually doing (usually "<IDLE>" or the start of the query to - * be executed). - * ---------- - */ -void -pgstat_report_activity(char *what) -{ - PgStat_MsgActivity msg; - int len; - - if (!pgstat_collect_querystring || pgStatSock < 0) - return; - - len = strlen(what); -#ifdef MULTIBYTE - len = pg_mbcliplen((const unsigned char *)what, len, PGSTAT_ACTIVITY_SIZE - 1); -#else - if (len >= PGSTAT_ACTIVITY_SIZE) - len = PGSTAT_ACTIVITY_SIZE - 1; -#endif - - memcpy(msg.m_what, what, len); - msg.m_what[len] = '\0'; - len += offsetof(PgStat_MsgActivity, m_what) +1; - - pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_ACTIVITY); - pgstat_send(&msg, len); -} - - -/* ---------- - * pgstat_report_tabstat() - - * - * Called from tcop/postgres.c to send the so far collected - * per table access statistics to the collector. - * ---------- - */ -void -pgstat_report_tabstat(void) -{ - int i; - int n; - int len; - - if (!pgstat_collect_querystring && !pgstat_collect_tuplelevel && - !pgstat_collect_blocklevel) - return; - - if (pgStatSock < 0) - return; - - /* - * For each message buffer used during the last query set the header - * fields and send it out. - */ - for (i = 0; i < pgStatTabstatUsed; i++) - { - n = pgStatTabstatMessages[i]->m_nentries; - len = offsetof(PgStat_MsgTabstat, m_entry[0]) + - n * sizeof(PgStat_TableEntry); - - pgStatTabstatMessages[i]->m_xact_commit = pgStatXactCommit; - pgStatTabstatMessages[i]->m_xact_rollback = pgStatXactRollback; - pgStatXactCommit = 0; - pgStatXactRollback = 0; - - pgstat_setheader(&pgStatTabstatMessages[i]->m_hdr, - PGSTAT_MTYPE_TABSTAT); - pgstat_send(pgStatTabstatMessages[i], len); - } - - pgStatTabstatUsed = 0; -} - - -/* ---------- - * pgstat_vacuum_tabstat() - - * - * Will tell the collector about objects he can get rid of. - * ---------- - */ -int -pgstat_vacuum_tabstat(void) -{ - Relation dbrel; - HeapScanDesc dbscan; - HeapTuple dbtup; - Oid *dbidlist; - int dbidalloc; - int dbidused; - HASH_SEQ_STATUS hstat; - PgStat_StatDBEntry *dbentry; - PgStat_StatTabEntry *tabentry; - HeapTuple reltup; - int nobjects = 0; - PgStat_MsgTabpurge msg; - int len; - int i; - - if (pgStatSock < 0) - return 0; - - /* - * We don't vacuum inside of transaction blocks, because a possible - * later rollback might reactivate objects we didn't find because of - * earlier destruction in the xact. - */ - if (IsTransactionBlock()) - return 0; - - /* - * If not done for this transaction, read the statistics collector - * stats file into some hash tables. - */ - if (!TransactionIdEquals(pgStatDBHashXact, GetCurrentTransactionId())) - { - pgstat_read_statsfile(&pgStatDBHash, MyDatabaseId, - &pgStatBeTable, &pgStatNumBackends); - pgStatDBHashXact = GetCurrentTransactionId(); - } - - /* - * Lookup our own database entry - */ - dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash, - (void *) &MyDatabaseId, - HASH_FIND, NULL); - if (dbentry == NULL) - return -1; - - if (dbentry->tables == NULL) - return 0; - - /* - * Initialize our messages table counter to zero - */ - msg.m_nentries = 0; - - /* - * Check for all tables if they still exist. - */ - hash_seq_init(&hstat, dbentry->tables); - while ((tabentry = (PgStat_StatTabEntry *) hash_seq_search(&hstat)) != NULL) - { - /* - * Check if this relation is still alive by looking up it's - * pg_class tuple in the system catalog cache. - */ - reltup = SearchSysCache(RELOID, - ObjectIdGetDatum(tabentry->tableid), - 0, 0, 0); - if (HeapTupleIsValid(reltup)) - { - ReleaseSysCache(reltup); - continue; - } - - /* - * Add this tables Oid to the message - */ - msg.m_tableid[msg.m_nentries++] = tabentry->tableid; - nobjects++; - - /* - * If the message is full, send it out and reinitialize ot zero - */ - 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); - 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); - pgstat_send(&msg, len); - } - - /* - * Read pg_database and remember the Oid's of all existing databases - */ - dbidalloc = 256; - dbidused = 0; - dbidlist = (Oid *) palloc(sizeof(Oid) * dbidalloc); - - dbrel = heap_openr(DatabaseRelationName, AccessShareLock); - dbscan = heap_beginscan(dbrel, SnapshotNow, 0, NULL); - while ((dbtup = heap_getnext(dbscan, ForwardScanDirection)) != NULL) - { - if (dbidused >= dbidalloc) - { - dbidalloc *= 2; - dbidlist = (Oid *) repalloc((char *) dbidlist, - sizeof(Oid) * dbidalloc); - } - dbidlist[dbidused++] = dbtup->t_data->t_oid; - } - heap_endscan(dbscan); - heap_close(dbrel, AccessShareLock); - - /* - * Search the database hash table for dead databases and tell the - * collector to drop them as well. - */ - hash_seq_init(&hstat, pgStatDBHash); - while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL) - { - Oid dbid = dbentry->databaseid; - - for (i = 0; i < dbidused; i++) - { - if (dbidlist[i] == dbid) - { - dbid = InvalidOid; - break; - } - } - - if (dbid != InvalidOid) - { - nobjects++; - pgstat_drop_database(dbid); - } - } - - /* - * Free the dbid list. - */ - pfree((char *) dbidlist); - - /* - * Tell the caller how many removeable objects we found - */ - return nobjects; -} - - -/* ---------- - * pgstat_drop_database() - - * - * Tell the collector that we just dropped a database. - * This is the only message that shouldn't get lost in space. Otherwise - * the collector will keep the statistics for the dead DB until his - * stats file got removed while the postmaster is down. - * ---------- - */ -static void -pgstat_drop_database(Oid databaseid) -{ - PgStat_MsgDropdb msg; - - if (pgStatSock < 0) - return; - - msg.m_databaseid = databaseid; - - pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_DROPDB); - pgstat_send(&msg, sizeof(msg)); -} - - -/* ---------- - * pgstat_reset_counters() - - * - * Tell the statistics collector to reset counters for our database. - * ---------- - */ -void -pgstat_reset_counters(void) -{ - PgStat_MsgResetcounter msg; - - if (pgStatSock < 0) - return; - - if (!superuser()) - elog(ERROR, "Only database superusers can reset statistic counters"); - - pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETCOUNTER); - pgstat_send(&msg, sizeof(msg)); -} - - -/* ---------- - * pgstat_ping() - - * - * Send some junk data to the collector to increase traffic. - * ---------- - */ -void -pgstat_ping(void) -{ - PgStat_MsgDummy msg; - - if (pgStatSock < 0) - return; - - pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_DUMMY); - pgstat_send(&msg, sizeof(msg)); -} - - -/* ---------- - * pgstat_initstats() - - * - * Called from various places usually dealing with initialization - * of Relation or Scan structures. The data placed into these - * structures from here tell where later to count for buffer reads, - * scans and tuples fetched. - * ---------- - */ -void -pgstat_initstats(PgStat_Info *stats, Relation rel) -{ - PgStat_TableEntry *useent = NULL; - Oid rel_id = rel->rd_id; - int mb; - int i; - - /* - * Initialize data not to count at all. - */ - stats->tabentry = NULL; - stats->no_stats = FALSE; - stats->heap_scan_counted = FALSE; - stats->index_scan_counted = FALSE; - - if (pgStatSock < 0) - { - stats->no_stats = TRUE; - return; - } - - /* - * On the first of all calls initialize the message buffers. - */ - if (pgStatTabstatAlloc == 0) - { - pgStatTabstatAlloc = 4; - pgStatTabstatMessages = (PgStat_MsgTabstat **) - malloc(sizeof(PgStat_MsgTabstat *) * pgStatTabstatAlloc); - if (pgStatTabstatMessages == NULL) - { - elog(LOG, "PGSTATBE: malloc() failed"); - return; - } - for (i = 0; i < pgStatTabstatAlloc; i++) - { - pgStatTabstatMessages[i] = (PgStat_MsgTabstat *) - malloc(sizeof(PgStat_MsgTabstat)); - if (pgStatTabstatMessages[i] == NULL) - { - elog(LOG, "PGSTATBE: malloc() failed"); - return; - } - } - } - - /* - * Lookup the so far used table slots for this relation. - */ - for (mb = 0; mb < pgStatTabstatUsed; mb++) - { - for (i = 0; i < pgStatTabstatMessages[mb]->m_nentries; i++) - { - if (pgStatTabstatMessages[mb]->m_entry[i].t_id == rel_id) - { - stats->tabentry = (void *) &(pgStatTabstatMessages[mb]->m_entry[i]); - return; - } - } - - if (pgStatTabstatMessages[mb]->m_nentries >= PGSTAT_NUM_TABENTRIES) - continue; - - /* - * Not found, but found a message buffer with an empty slot - * instead. Fine, let's use this one. - */ - i = pgStatTabstatMessages[mb]->m_nentries++; - useent = &pgStatTabstatMessages[mb]->m_entry[i]; - memset(useent, 0, sizeof(PgStat_TableEntry)); - useent->t_id = rel_id; - stats->tabentry = (void *) useent; - return; - } - - /* - * If we ran out of message buffers, we just allocate more. - */ - if (pgStatTabstatUsed >= pgStatTabstatAlloc) - { - pgStatTabstatAlloc += 4; - pgStatTabstatMessages = (PgStat_MsgTabstat **) - realloc(pgStatTabstatMessages, - sizeof(PgStat_MsgTabstat *) * pgStatTabstatAlloc); - if (pgStatTabstatMessages == NULL) - { - pgStatTabstatAlloc -= 4; - elog(LOG, "PGSTATBE: malloc() failed"); - return; - } - for (i = pgStatTabstatUsed; i < pgStatTabstatAlloc; i++) - { - pgStatTabstatMessages[i] = (PgStat_MsgTabstat *) - malloc(sizeof(PgStat_MsgTabstat)); - if (pgStatTabstatMessages[i] == NULL) - { - pgStatTabstatAlloc -= 4; - elog(LOG, "PGSTATBE: malloc() failed"); - return; - } - } - } - - /* - * Use the first entry of the next message buffer. - */ - mb = pgStatTabstatUsed++; - pgStatTabstatMessages[mb]->m_nentries = 1; - useent = &pgStatTabstatMessages[mb]->m_entry[0]; - memset(useent, 0, sizeof(PgStat_TableEntry)); - useent->t_id = rel_id; - stats->tabentry = (void *) useent; - return; -} - - -/* ---------- - * pgstat_count_xact_commit() - - * - * Called from access/transam/xact.c to count transaction commits. - * ---------- - */ -void -pgstat_count_xact_commit(void) -{ - if (!pgstat_collect_querystring && !pgstat_collect_tuplelevel && - !pgstat_collect_blocklevel) - return; - - pgStatXactCommit++; - - /* - * If there was no relation activity yet, just make one existing - * message buffer used without slots, causing the next report to tell - * new xact-counters. - */ - if (pgStatTabstatAlloc > 0) - { - if (pgStatTabstatUsed == 0) - { - pgStatTabstatUsed++; - pgStatTabstatMessages[0]->m_nentries = 0; - } - } -} - - -/* ---------- - * pgstat_count_xact_rollback() - - * - * Called from access/transam/xact.c to count transaction rollbacks. - * ---------- - */ -void -pgstat_count_xact_rollback(void) -{ - if (!pgstat_collect_querystring && !pgstat_collect_tuplelevel && - !pgstat_collect_blocklevel) - return; - - pgStatXactRollback++; - - /* - * If there was no relation activity yet, just make one existing - * message buffer used without slots, causing the next report to tell - * new xact-counters. - */ - if (pgStatTabstatAlloc > 0) - { - if (pgStatTabstatUsed == 0) - { - pgStatTabstatUsed++; - pgStatTabstatMessages[0]->m_nentries = 0; - } - } -} - - -/* ---------- - * pgstat_fetch_stat_dbentry() - - * - * Support function for the SQL-callable pgstat* functions. Returns - * the collected statistics for one database or NULL. NULL doesn't mean - * that the database doesn't exist, it is just not yet known by the - * collector, so the caller is better off to report ZERO instead. - * ---------- - */ -PgStat_StatDBEntry * -pgstat_fetch_stat_dbentry(Oid dbid) -{ - PgStat_StatDBEntry *dbentry; - - /* - * If not done for this transaction, read the statistics collector - * stats file into some hash tables. Be careful with the - * read_statsfile() call below! - */ - if (!TransactionIdEquals(pgStatDBHashXact, GetCurrentTransactionId())) - { - pgstat_read_statsfile(&pgStatDBHash, MyDatabaseId, - &pgStatBeTable, &pgStatNumBackends); - pgStatDBHashXact = GetCurrentTransactionId(); - } - - /* - * Lookup the requested database - */ - dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash, - (void *) &dbid, - HASH_FIND, NULL); - if (dbentry == NULL) - return NULL; - - return dbentry; -} - - -/* ---------- - * 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) -{ - PgStat_StatDBEntry *dbentry; - PgStat_StatTabEntry *tabentry; - - /* - * If not done for this transaction, read the statistics collector - * stats file into some hash tables. Be careful with the - * read_statsfile() call below! - */ - if (!TransactionIdEquals(pgStatDBHashXact, GetCurrentTransactionId())) - { - pgstat_read_statsfile(&pgStatDBHash, MyDatabaseId, - &pgStatBeTable, &pgStatNumBackends); - pgStatDBHashXact = GetCurrentTransactionId(); - } - - /* - * Lookup our database. - */ - dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash, - (void *) &MyDatabaseId, - HASH_FIND, NULL); - if (dbentry == NULL) - return NULL; - - /* - * Now inside the DB's table hash table lookup the requested one. - */ - if (dbentry->tables == NULL) - return NULL; - tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables, - (void *) &relid, - HASH_FIND, NULL); - if (tabentry == NULL) - return NULL; - - return tabentry; -} - - -/* ---------- - * pgstat_fetch_stat_beentry() - - * - * Support function for the SQL-callable pgstat* functions. Returns - * the actual activity slot of one active backend. The caller is - * responsible for a check if the actual user is permitted to see - * that info (especially the querystring). - * ---------- - */ -PgStat_StatBeEntry * -pgstat_fetch_stat_beentry(int beid) -{ - if (!TransactionIdEquals(pgStatDBHashXact, GetCurrentTransactionId())) - { - pgstat_read_statsfile(&pgStatDBHash, MyDatabaseId, - &pgStatBeTable, &pgStatNumBackends); - pgStatDBHashXact = GetCurrentTransactionId(); - } - - if (beid < 1 || beid > pgStatNumBackends) - return NULL; - - return &pgStatBeTable[beid - 1]; -} - - -/* ---------- - * pgstat_fetch_stat_numbackends() - - * - * Support function for the SQL-callable pgstat* functions. Returns - * the maximum current backend id. - * ---------- - */ -int -pgstat_fetch_stat_numbackends(void) -{ - if (!TransactionIdEquals(pgStatDBHashXact, GetCurrentTransactionId())) - { - pgstat_read_statsfile(&pgStatDBHash, MyDatabaseId, - &pgStatBeTable, &pgStatNumBackends); - pgStatDBHashXact = GetCurrentTransactionId(); - } - - return pgStatNumBackends; -} - - - -/* ------------------------------------------------------------ - * Local support functions follow - * ------------------------------------------------------------ - */ - - -/* ---------- - * pgstat_setheader() - - * - * Set common header fields in a statistics message - * ---------- - */ -static void -pgstat_setheader(PgStat_MsgHdr *hdr, int mtype) -{ - hdr->m_type = mtype; - hdr->m_backendid = MyBackendId; - hdr->m_procpid = MyProcPid; - hdr->m_databaseid = MyDatabaseId; - hdr->m_userid = GetSessionUserId(); -} - - -/* ---------- - * pgstat_send() - - * - * Send out one statistics message to the collector - * ---------- - */ -static void -pgstat_send(void *msg, int len) -{ - if (pgStatSock < 0) - return; - - ((PgStat_MsgHdr *) msg)->m_size = len; - - send(pgStatSock, msg, len, 0); - /* We deliberately ignore any error from send() */ -} - - -/* ------------------------------------------------------------ - * Local functions implementing the statistics collector itself follow - *------------------------------------------------------------ - */ - - -/* ---------- - * pgstat_main() - - * - * Start up the statistics collector itself. This is the body of the - * postmaster child process. - * ---------- - */ -static void -pgstat_main(void) -{ - PgStat_Msg msg; - fd_set rfds; - int readPipe; - int pmPipe = pgStatPmPipe[0]; - int maxfd; - int nready; - int len = 0; - struct timeval timeout; - struct timeval next_statwrite; - bool need_statwrite; - HASHCTL hash_ctl; - - /* - * Close the writing end of the postmaster pipe, so we'll see it - * closing when the postmaster terminates and can terminate as well. - */ - close(pgStatPmPipe[1]); - pgStatPmPipe[1] = -1; - - /* - * Ignore all signals usually bound to some action in the postmaster, - * except for SIGCHLD --- see pgstat_recvbuffer. - */ - pqsignal(SIGHUP, SIG_IGN); - pqsignal(SIGINT, SIG_IGN); - pqsignal(SIGTERM, SIG_IGN); - pqsignal(SIGQUIT, SIG_IGN); - pqsignal(SIGALRM, SIG_IGN); - pqsignal(SIGPIPE, SIG_IGN); - pqsignal(SIGUSR1, SIG_IGN); - pqsignal(SIGUSR2, SIG_IGN); - pqsignal(SIGCHLD, pgstat_die); - pqsignal(SIGTTIN, SIG_DFL); - pqsignal(SIGTTOU, SIG_DFL); - pqsignal(SIGCONT, SIG_DFL); - pqsignal(SIGWINCH, SIG_DFL); - - /* - * Start a buffering process to read from the socket, so we have a - * little more time to process incoming messages. - * - * NOTE: the process structure is: postmaster is parent of buffer process - * is parent of collector process. This way, the buffer can detect - * collector failure via SIGCHLD, whereas otherwise it wouldn't notice - * collector failure until it tried to write on the pipe. That would - * mean that after the postmaster started a new collector, we'd have - * two buffer processes competing to read from the UDP socket --- not - * good. - */ - if (pipe(pgStatPipe) < 0) - { - elog(LOG, "PGSTAT: pipe() failed: %m"); - exit(1); - } - - switch (fork()) - { - case -1: - elog(LOG, "PGSTAT: fork() failed: %m"); - exit(1); - - case 0: - /* child becomes collector process */ - close(pgStatPipe[1]); - close(pgStatSock); - break; - - default: - /* parent becomes buffer process */ - close(pgStatPipe[0]); - pgstat_recvbuffer(); - exit(0); - } - - /* - * In the child we can have default SIGCHLD handling (in case we want - * to call system() here...) - */ - pqsignal(SIGCHLD, SIG_DFL); - - /* - * Identify myself via ps - */ - init_ps_display("stats collector process", "", ""); - set_ps_display(""); - - /* - * Arrange to write the initial status file right away - */ - gettimeofday(&next_statwrite, NULL); - need_statwrite = TRUE; - - /* - * Read in an existing statistics stats file or initialize the stats - * to zero. - */ - pgStatRunningInCollector = TRUE; - pgstat_read_statsfile(&pgStatDBHash, InvalidOid, NULL, NULL); - - /* - * Create the dead backend hashtable - */ - memset(&hash_ctl, 0, sizeof(hash_ctl)); - hash_ctl.keysize = sizeof(int); - hash_ctl.entrysize = sizeof(PgStat_StatBeDead); - hash_ctl.hash = tag_hash; - pgStatBeDead = hash_create("Dead Backends", PGSTAT_BE_HASH_SIZE, - &hash_ctl, HASH_ELEM | HASH_FUNCTION); - if (pgStatBeDead == NULL) - { - elog(LOG, "PGSTAT: Creation of dead backend hash table failed"); - exit(1); - } - - /* - * Create the known backends table - */ - pgStatBeTable = (PgStat_StatBeEntry *) malloc( - sizeof(PgStat_StatBeEntry) * MaxBackends); - if (pgStatBeTable == NULL) - { - elog(LOG, "PGSTAT: Allocation of backend table failed"); - exit(1); - } - memset(pgStatBeTable, 0, sizeof(PgStat_StatBeEntry) * MaxBackends); - - readPipe = pgStatPipe[0]; - - /* - * Process incoming messages and handle all the reporting stuff until - * there are no more messages. - */ - for (;;) - { - /* - * If we need to write the status file again (there have been - * changes in the statistics since we wrote it last) calculate the - * timeout until we have to do so. - */ - if (need_statwrite) - { - gettimeofday(&timeout, NULL); - timeout.tv_usec = next_statwrite.tv_usec - timeout.tv_usec; - timeout.tv_sec = next_statwrite.tv_sec - timeout.tv_sec; - if (timeout.tv_usec < 0) - { - timeout.tv_sec -= 1; - timeout.tv_usec += 1000000; - } - if (timeout.tv_sec < 0) - { - timeout.tv_sec = 0; - timeout.tv_usec = 0; - } - } - - /* - * Setup the descriptor set for select(2) - */ - FD_ZERO(&rfds); - FD_SET(readPipe, &rfds); - FD_SET(pmPipe, &rfds); - - if (readPipe > pmPipe) - maxfd = readPipe; - else - maxfd = pmPipe; - - /* - * Now wait for something to do. - */ - nready = select(maxfd + 1, &rfds, NULL, NULL, - (need_statwrite) ? &timeout : NULL); - if (nready < 0) - { - if (errno == EINTR) - continue; - elog(LOG, "PGSTAT: select() failed: %m"); - exit(1); - } - - /* - * If there are no descriptors ready, our timeout for writing the - * stats file happened. - */ - if (nready == 0) - { - pgstat_write_statsfile(); - need_statwrite = FALSE; - - continue; - } - - /* - * Check if there is a new statistics message to collect. - */ - if (FD_ISSET(readPipe, &rfds)) - { - /* - * We may need to issue multiple read calls in case the buffer - * process didn't write the message in a single write, which - * is possible since it dumps its buffer bytewise. In any - * case, we'd need two reads since we don't know the message - * length initially. - */ - int nread = 0; - int targetlen = sizeof(PgStat_MsgHdr); /* initial */ - - while (nread < targetlen) - { - len = read(readPipe, - ((char *) &msg) + nread, - targetlen - nread); - if (len < 0) - { - if (errno == EINTR) - continue; - elog(LOG, "PGSTAT: read() failed: %m"); - exit(1); - } - if (len == 0) /* EOF on the pipe! */ - break; - nread += len; - if (nread == sizeof(PgStat_MsgHdr)) - { - /* we have the header, compute actual msg length */ - targetlen = msg.msg_hdr.m_size; - if (targetlen < (int) sizeof(PgStat_MsgHdr) || - targetlen > (int) sizeof(msg)) - { - /* - * Bogus message length implies that we got out of - * sync with the buffer process somehow. Abort so - * that we can restart both processes. - */ - elog(LOG, "PGSTAT: bogus message length"); - exit(1); - } - } - } - - /* - * EOF on the pipe implies that the buffer process exited. - * Fall out of outer loop. - */ - if (len == 0) - break; - - /* - * Distribute the message to the specific function handling - * it. - */ - switch (msg.msg_hdr.m_type) - { - case PGSTAT_MTYPE_DUMMY: - break; - - case PGSTAT_MTYPE_BESTART: - pgstat_recv_bestart((PgStat_MsgBestart *) &msg, nread); - break; - - case PGSTAT_MTYPE_BETERM: - pgstat_recv_beterm((PgStat_MsgBeterm *) &msg, nread); - break; - - case PGSTAT_MTYPE_TABSTAT: - pgstat_recv_tabstat((PgStat_MsgTabstat *) &msg, nread); - break; - - case PGSTAT_MTYPE_TABPURGE: - pgstat_recv_tabpurge((PgStat_MsgTabpurge *) &msg, nread); - break; - - case PGSTAT_MTYPE_ACTIVITY: - pgstat_recv_activity((PgStat_MsgActivity *) &msg, nread); - break; - - case PGSTAT_MTYPE_DROPDB: - pgstat_recv_dropdb((PgStat_MsgDropdb *) &msg, nread); - break; - - case PGSTAT_MTYPE_RESETCOUNTER: - pgstat_recv_resetcounter((PgStat_MsgResetcounter *) &msg, - nread); - break; - - default: - break; - } - - /* - * Globally count messages. - */ - pgStatNumMessages++; - - /* - * If this is the first message after we wrote the stats file - * the last time, setup the timeout that it'd be written. - */ - if (!need_statwrite) - { - gettimeofday(&next_statwrite, NULL); - next_statwrite.tv_usec += ((PGSTAT_STAT_INTERVAL) * 1000); - next_statwrite.tv_sec += (next_statwrite.tv_usec / 1000000); - next_statwrite.tv_usec %= 1000000; - need_statwrite = TRUE; - } - } - - /* - * Note that we do NOT check for postmaster exit inside the loop; - * only EOF on the buffer pipe causes us to fall out. This - * ensures we don't exit prematurely if there are still a few - * messages in the buffer or pipe at postmaster shutdown. - */ - } - - /* - * Okay, we saw EOF on the buffer pipe, so there are no more messages - * to process. If the buffer process quit because of postmaster - * shutdown, we want to save the final stats to reuse at next startup. - * But if the buffer process failed, it seems best not to (there may - * even now be a new collector firing up, and we don't want it to read - * a partially- rewritten stats file). We can tell whether the - * postmaster is still alive by checking to see if the postmaster pipe - * is still open. If it is read-ready (ie, EOF), the postmaster must - * have quit. - */ - if (FD_ISSET(pmPipe, &rfds)) - pgstat_write_statsfile(); -} - - -/* ---------- - * pgstat_recvbuffer() - - * - * This is the body of the separate buffering process. Its only - * purpose is to receive messages from the UDP socket as fast as - * possible and forward them over a pipe into the collector itself. - * If the collector is slow to absorb messages, they are buffered here. - * ---------- - */ -static void -pgstat_recvbuffer(void) -{ - fd_set rfds; - fd_set wfds; - int writePipe = pgStatPipe[1]; - int pmPipe = pgStatPmPipe[0]; - int maxfd; - int nready; - int len; - int xfr; - int frm; - PgStat_Msg input_buffer; - char *msgbuffer; - int msg_send = 0; /* next send index in buffer */ - int msg_recv = 0; /* next receive index */ - int msg_have = 0; /* number of bytes stored */ - struct sockaddr_in fromaddr; - int fromlen; - bool overflow = false; - - /* - * Identify myself via ps - */ - init_ps_display("stats buffer process", "", ""); - set_ps_display(""); - - /* - * We want to die if our child collector process does. There are two - * ways we might notice that it has died: receive SIGCHLD, or get a - * write failure on the pipe leading to the child. We can set SIGPIPE - * to kill us here. Our SIGCHLD handler was already set up before we - * forked (must do it that way, else it's a race condition). - */ - pqsignal(SIGPIPE, SIG_DFL); - PG_SETMASK(&UnBlockSig); - - /* - * Set the write pipe to nonblock mode, so that we cannot block when - * the collector falls behind. - */ - if (fcntl(writePipe, F_SETFL, O_NONBLOCK) < 0) - { - elog(LOG, "PGSTATBUFF: fcntl() failed: %m"); - exit(1); - } - - /* - * Allocate the message buffer - */ - msgbuffer = (char *) malloc(PGSTAT_RECVBUFFERSZ); - if (msgbuffer == NULL) - { - elog(LOG, "PGSTATBUFF: malloc() failed"); - exit(1); - } - - /* - * Loop forever - */ - for (;;) - { - FD_ZERO(&rfds); - FD_ZERO(&wfds); - maxfd = -1; - - /* - * As long as we have buffer space we add the socket to the read - * descriptor set. - */ - if (msg_have <= (int) (PGSTAT_RECVBUFFERSZ - sizeof(PgStat_Msg))) - { - FD_SET(pgStatSock, &rfds); - maxfd = pgStatSock; - overflow = false; - } - else - { - if (!overflow) - { - elog(LOG, "PGSTATBUFF: Warning - receive buffer full"); - overflow = true; - } - } - - /* - * If we have messages to write out, we add the pipe to the write - * descriptor set. Otherwise, we check if the postmaster might - * have terminated. - */ - if (msg_have > 0) - { - FD_SET(writePipe, &wfds); - if (writePipe > maxfd) - maxfd = writePipe; - } - else - { - FD_SET(pmPipe, &rfds); - if (pmPipe > maxfd) - maxfd = pmPipe; - } - - /* - * Wait for some work to do. - */ - nready = select(maxfd + 1, &rfds, &wfds, NULL, NULL); - if (nready < 0) - { - if (errno == EINTR) - continue; - elog(LOG, "PGSTATBUFF: select() failed: %m"); - exit(1); - } - - /* - * If there is a message on the socket, read it and check for - * validity. - */ - if (FD_ISSET(pgStatSock, &rfds)) - { - fromlen = sizeof(fromaddr); - len = recvfrom(pgStatSock, - &input_buffer, sizeof(PgStat_Msg), 0, - (struct sockaddr *) &fromaddr, &fromlen); - if (len < 0) - { - elog(LOG, "PGSTATBUFF: recvfrom() failed: %m"); - exit(1); - } - - /* - * 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 (input_buffer.msg_hdr.m_size != len) - continue; - - /* - * The source address of the packet must be our own socket. - * This ensures that only real hackers or our own backends - * tell us something. (This should be redundant with a - * kernel-level check due to having used connect(), but let's - * do it anyway.) - */ - if (fromaddr.sin_addr.s_addr != pgStatAddr.sin_addr.s_addr) - continue; - if (fromaddr.sin_port != pgStatAddr.sin_port) - continue; - - /* - * O.K. - we accept this message. Copy it to the circular - * msgbuffer. - */ - frm = 0; - while (len > 0) - { - xfr = PGSTAT_RECVBUFFERSZ - msg_recv; - if (xfr > len) - xfr = len; - Assert(xfr > 0); - memcpy(msgbuffer + msg_recv, - ((char *) &input_buffer) + frm, - xfr); - msg_recv += xfr; - if (msg_recv == PGSTAT_RECVBUFFERSZ) - msg_recv = 0; - msg_have += xfr; - frm += xfr; - len -= xfr; - } - } - - /* - * If the collector is ready to receive, write some data into his - * pipe. We may or may not be able to write all that we have. - * - * NOTE: if what we have is less than PIPE_BUF bytes but more than - * the space available in the pipe buffer, most kernels will - * refuse to write any of it, and will return EAGAIN. This means - * we will busy-loop until the situation changes (either because - * the collector caught up, or because more data arrives so that - * we have more than PIPE_BUF bytes buffered). This is not good, - * but is there any way around it? We have no way to tell when - * the collector has caught up... - */ - if (FD_ISSET(writePipe, &wfds)) - { - xfr = PGSTAT_RECVBUFFERSZ - msg_send; - if (xfr > msg_have) - xfr = msg_have; - Assert(xfr > 0); - len = write(writePipe, msgbuffer + msg_send, xfr); - if (len < 0) - { - if (errno == EINTR || errno == EAGAIN) - continue; /* not enough space in pipe */ - elog(LOG, "PGSTATBUFF: write() failed: %m"); - exit(1); - } - /* NB: len < xfr is okay */ - msg_send += len; - if (msg_send == PGSTAT_RECVBUFFERSZ) - msg_send = 0; - msg_have -= len; - } - - /* - * Make sure we forwarded all messages before we check for - * Postmaster termination. - */ - if (msg_have != 0 || FD_ISSET(pgStatSock, &rfds)) - continue; - - /* - * If the pipe from the postmaster is ready for reading, the - * kernel must have closed it on exit() (the postmaster never - * really writes to it). So we've done our job. - */ - if (FD_ISSET(pmPipe, &rfds)) - exit(0); - } -} - -static void -pgstat_die(SIGNAL_ARGS) -{ - exit(1); -} - - -/* ---------- - * pgstat_add_backend() - - * - * Support function to keep our backend list up to date. - * ---------- - */ -static int -pgstat_add_backend(PgStat_MsgHdr *msg) -{ - PgStat_StatDBEntry *dbentry; - PgStat_StatBeEntry *beentry; - PgStat_StatBeDead *deadbe; - bool found; - - /* - * Check that the backend ID is valid - */ - if (msg->m_backendid < 1 || msg->m_backendid > MaxBackends) - { - elog(LOG, "PGSTAT: Invalid backend ID %d", msg->m_backendid); - return -1; - } - - /* - * Get the slot for this backendid. - */ - beentry = &pgStatBeTable[msg->m_backendid - 1]; - if (beentry->databaseid != InvalidOid) - { - /* - * If the slot contains the PID of this backend, everything is - * fine and we got nothing to do. - */ - if (beentry->procpid == msg->m_procpid) - return 0; - } - - /* - * Lookup if this backend is known to be dead. This can be caused due - * to messages arriving in the wrong order - i.e. Postmaster's BETERM - * message might have arrived before we received all the backends - * stats messages, or even a new backend with the same backendid was - * faster in sending his BESTART. - * - * If the backend is known to be dead, we ignore this add. - */ - deadbe = (PgStat_StatBeDead *) hash_search(pgStatBeDead, - (void *) &(msg->m_procpid), - HASH_FIND, NULL); - if (deadbe) - return 1; - - /* - * Backend isn't known to be dead. If it's slot is currently used, we - * have to kick out the old backend. - */ - if (beentry->databaseid != InvalidOid) - pgstat_sub_backend(beentry->procpid); - - /* - * Put this new backend into the slot. - */ - beentry->databaseid = msg->m_databaseid; - beentry->procpid = msg->m_procpid; - beentry->userid = msg->m_userid; - MemSet(beentry->activity, 0, PGSTAT_ACTIVITY_SIZE); - - /* - * Lookup or create the database entry for this backends DB. - */ - dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash, - (void *) &(msg->m_databaseid), - HASH_ENTER, &found); - if (dbentry == NULL) - { - elog(LOG, "PGSTAT: DB hash table out of memory - abort"); - exit(1); - } - - /* - * If not found, initialize the new one. - */ - if (!found) - { - HASHCTL hash_ctl; - - dbentry->tables = NULL; - dbentry->n_xact_commit = 0; - dbentry->n_xact_rollback = 0; - dbentry->n_blocks_fetched = 0; - dbentry->n_blocks_hit = 0; - dbentry->n_connects = 0; - dbentry->destroy = 0; - - memset(&hash_ctl, 0, sizeof(hash_ctl)); - hash_ctl.keysize = sizeof(Oid); - hash_ctl.entrysize = sizeof(PgStat_StatTabEntry); - hash_ctl.hash = tag_hash; - dbentry->tables = hash_create("Per-database table", - PGSTAT_TAB_HASH_SIZE, - &hash_ctl, - HASH_ELEM | HASH_FUNCTION); - if (dbentry->tables == NULL) - { - elog(LOG, "PGSTAT: failed to initialize hash table for " - "new database entry"); - exit(1); - } - } - - /* - * Count number of connects to the database - */ - dbentry->n_connects++; - - return 0; -} - - -/* ---------- - * pgstat_sub_backend() - - * - * Remove a backend from the actual backends list. - * ---------- - */ -static void -pgstat_sub_backend(int procpid) -{ - int i; - PgStat_StatBeDead *deadbe; - bool found; - - /* - * Search in the known-backends table for the slot containing this - * PID. - */ - for (i = 0; i < MaxBackends; i++) - { - if (pgStatBeTable[i].databaseid != InvalidOid && - pgStatBeTable[i].procpid == procpid) - { - /* - * That's him. Add an entry to the known to be dead backends. - * Due to possible misorder in the arrival of UDP packets it's - * possible that even if we know the backend is dead, there - * could still be messages queued that arrive later. Those - * messages must not cause our number of backends statistics - * to get screwed up, so we remember for a couple of seconds - * that this PID is dead and ignore them (only the counting of - * backends, not the table access stats they sent). - */ - deadbe = (PgStat_StatBeDead *) hash_search(pgStatBeDead, - (void *) &procpid, - HASH_ENTER, &found); - if (deadbe == NULL) - { - elog(LOG, "PGSTAT: dead backend hash table out of memory"); - exit(1); - } - if (!found) - { - deadbe->backendid = i + 1; - deadbe->destroy = PGSTAT_DESTROY_COUNT; - } - - /* - * Declare the backend slot empty. - */ - pgStatBeTable[i].databaseid = InvalidOid; - return; - } - } - - /* - * No big problem if not found. This can happen if UDP messages arrive - * out of order here. - */ -} - - -/* ---------- - * pgstat_write_statsfile() - - * - * Tell the news. - * ---------- - */ -static void -pgstat_write_statsfile(void) -{ - HASH_SEQ_STATUS hstat; - HASH_SEQ_STATUS tstat; - PgStat_StatDBEntry *dbentry; - PgStat_StatTabEntry *tabentry; - PgStat_StatBeDead *deadbe; - FILE *fpout; - int i; - - /* - * Open the statistics temp file to write out the current values. - */ - fpout = fopen(pgStat_tmpfname, PG_BINARY_W); - if (fpout == NULL) - { - elog(LOG, "PGSTAT: cannot open temp stats file %s: %m", - pgStat_tmpfname); - return; - } - - /* - * Walk through the database table. - */ - hash_seq_init(&hstat, pgStatDBHash); - while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL) - { - /* - * If this database is marked destroyed, count down and do so if - * it reaches 0. - */ - if (dbentry->destroy > 0) - { - if (--(dbentry->destroy) == 0) - { - if (dbentry->tables != NULL) - hash_destroy(dbentry->tables); - - if (hash_search(pgStatDBHash, - (void *) &(dbentry->databaseid), - HASH_REMOVE, NULL) == NULL) - { - elog(LOG, "PGSTAT: database hash table corrupted " - "during cleanup - abort"); - exit(1); - } - } - - /* - * Don't include statistics for it. - */ - continue; - } - - /* - * Write out the DB line including the number of life backends. - */ - fputc('D', fpout); - fwrite(dbentry, sizeof(PgStat_StatDBEntry), 1, fpout); - - /* - * Walk through the databases access stats per table. - */ - hash_seq_init(&tstat, dbentry->tables); - while ((tabentry = (PgStat_StatTabEntry *) hash_seq_search(&tstat)) != NULL) - { - /* - * If table entry marked for destruction, same as above for - * the database entry. - */ - if (tabentry->destroy > 0) - { - if (--(tabentry->destroy) == 0) - { - if (hash_search(dbentry->tables, - (void *) &(tabentry->tableid), - HASH_REMOVE, NULL) == NULL) - { - elog(LOG, "PGSTAT: tables hash table for " - "database %d corrupted during " - "cleanup - abort", - dbentry->databaseid); - exit(1); - } - } - continue; - } - - /* - * At least we think this is still a life table. Print it's - * access stats. - */ - fputc('T', fpout); - fwrite(tabentry, sizeof(PgStat_StatTabEntry), 1, fpout); - } - - /* - * Mark the end of this DB - */ - fputc('d', fpout); - } - - /* - * Write out the known running backends to the stats file. - */ - i = MaxBackends; - fputc('M', fpout); - fwrite(&i, sizeof(i), 1, fpout); - - for (i = 0; i < MaxBackends; i++) - { - if (pgStatBeTable[i].databaseid != InvalidOid) - { - fputc('B', fpout); - fwrite(&pgStatBeTable[i], sizeof(PgStat_StatBeEntry), 1, fpout); - } - } - - /* - * No more output to be done. Close the temp file and replace the old - * pgstat.stat with it's content. - */ - fputc('E', fpout); - if (fclose(fpout) < 0) - { - elog(LOG, "PGSTAT: Error closing temp stats file %s: %m", - pgStat_tmpfname); - } - else - { - if (rename(pgStat_tmpfname, pgStat_fname) < 0) - { - elog(LOG, "PGSTAT: Cannot rename temp stats file %s: %m", - pgStat_fname); - } - } - - /* - * Clear out the dead backends table - */ - hash_seq_init(&hstat, pgStatBeDead); - while ((deadbe = (PgStat_StatBeDead *) hash_seq_search(&hstat)) != NULL) - { - /* - * Count down the destroy delay and remove entries where it - * reaches 0. - */ - if (--(deadbe->destroy) <= 0) - { - if (hash_search(pgStatBeDead, - (void *) &(deadbe->procpid), - HASH_REMOVE, NULL) == NULL) - { - elog(LOG, "PGSTAT: dead backend hash table corrupted " - "during cleanup - abort"); - exit(1); - } - } - } -} - - -/* ---------- - * pgstat_read_statsfile() - - * - * Reads in an existing statistics collector and initializes the - * databases hash table (who's entries point to the tables hash tables) - * and the current backend table. - * ---------- - */ -static void -pgstat_read_statsfile(HTAB **dbhash, Oid onlydb, - PgStat_StatBeEntry **betab, int *numbackends) -{ - PgStat_StatDBEntry *dbentry; - PgStat_StatDBEntry dbbuf; - PgStat_StatTabEntry *tabentry; - PgStat_StatTabEntry tabbuf; - HASHCTL hash_ctl; - HTAB *tabhash = NULL; - FILE *fpin; - int maxbackends = 0; - int havebackends = 0; - bool found; - MemoryContext use_mcxt; - int mcxt_flags; - - /* - * If running in the collector we use the DynaHashCxt memory context. - * If running in a backend, we use the TopTransactionContext instead, - * so the caller must only know the last XactId when this call - * happened to know if his tables are still valid or already gone! - */ - if (pgStatRunningInCollector) - { - use_mcxt = NULL; - mcxt_flags = 0; - } - else - { - use_mcxt = TopTransactionContext; - mcxt_flags = HASH_CONTEXT; - } - - /* - * Create the DB hashtable - */ - memset(&hash_ctl, 0, sizeof(hash_ctl)); - hash_ctl.keysize = sizeof(Oid); - hash_ctl.entrysize = sizeof(PgStat_StatDBEntry); - hash_ctl.hash = tag_hash; - hash_ctl.hcxt = use_mcxt; - *dbhash = hash_create("Databases hash", PGSTAT_DB_HASH_SIZE, &hash_ctl, - HASH_ELEM | HASH_FUNCTION | mcxt_flags); - if (*dbhash == NULL) - { - if (pgStatRunningInCollector) - { - elog(LOG, "PGSTAT: Creation of DB hash table failed"); - exit(1); - } - /* in backend, can do normal error */ - elog(ERROR, "PGSTAT: Creation of DB hash table failed"); - } - - /* - * Initialize the number of known backends to zero, just in case we do - * a silent error return below. - */ - if (numbackends != NULL) - *numbackends = 0; - if (betab != NULL) - *betab = NULL; - - /* - * Try to open the status file. If it doesn't exist, the backends - * simply return zero for anything and the collector simply starts - * from scratch with empty counters. - */ - if ((fpin = fopen(pgStat_fname, PG_BINARY_R)) == NULL) - return; - - /* - * We found an existing collector stats file. Read it and put all the - * hashtable entries into place. - */ - for (;;) - { - switch (fgetc(fpin)) - { - /* - * 'D' A PgStat_StatDBEntry struct describing a database - * follows. Subsequently, zero to many 'T' entries will - * follow until a 'd' is encountered. - */ - case 'D': - if (fread(&dbbuf, 1, sizeof(dbbuf), fpin) != sizeof(dbbuf)) - { - if (pgStatRunningInCollector) - { - elog(LOG, "PGSTAT: corrupted pgstat.stat file"); - fclose(fpin); - return; - } - else - { - elog(WARNING, "PGSTAT: corrupted pgstat.stat file"); - fclose(fpin); - return; - } - } - - /* - * Add to the DB hash - */ - dbentry = (PgStat_StatDBEntry *) hash_search(*dbhash, - (void *) &dbbuf.databaseid, - HASH_ENTER, &found); - if (dbentry == NULL) - { - if (pgStatRunningInCollector) - { - elog(LOG, "PGSTAT: DB hash table out of memory"); - exit(1); - } - else - { - fclose(fpin); - elog(ERROR, "PGSTAT: DB hash table out of memory"); - } - } - if (found) - { - if (pgStatRunningInCollector) - { - elog(LOG, "PGSTAT: corrupted pgstat.stat file"); - fclose(fpin); - return; - } - else - { - elog(WARNING, "PGSTAT: corrupted pgstat.stat file"); - fclose(fpin); - return; - } - } - - memcpy(dbentry, &dbbuf, sizeof(PgStat_StatDBEntry)); - dbentry->tables = NULL; - dbentry->destroy = 0; - dbentry->n_backends = 0; - - /* - * Don't collect tables if not the requested DB - */ - if (onlydb != InvalidOid && onlydb != dbbuf.databaseid) - break; - - - memset(&hash_ctl, 0, sizeof(hash_ctl)); - hash_ctl.keysize = sizeof(Oid); - hash_ctl.entrysize = sizeof(PgStat_StatTabEntry); - hash_ctl.hash = tag_hash; - hash_ctl.hcxt = use_mcxt; - dbentry->tables = hash_create("Per-database table", - PGSTAT_TAB_HASH_SIZE, - &hash_ctl, - HASH_ELEM | HASH_FUNCTION | mcxt_flags); - if (dbentry->tables == NULL) - { - if (pgStatRunningInCollector) - { - elog(LOG, "PGSTAT: failed to initialize " - "hash table for new database entry"); - exit(1); - } - else - { - fclose(fpin); - elog(ERROR, "PGSTAT: failed to initialize " - "hash table for new database entry"); - } - } - - /* - * Arrange that following 'T's add entries to this - * databases tables hash table. - */ - tabhash = dbentry->tables; - break; - - /* - * 'd' End of this database. - */ - case 'd': - tabhash = NULL; - break; - - /* - * 'T' A PgStat_StatTabEntry follows. - */ - case 'T': - if (fread(&tabbuf, 1, sizeof(tabbuf), fpin) != sizeof(tabbuf)) - { - if (pgStatRunningInCollector) - { - elog(LOG, "PGSTAT: corrupted pgstat.stat file"); - fclose(fpin); - return; - } - else - { - elog(WARNING, "PGSTAT: corrupted pgstat.stat file"); - fclose(fpin); - return; - } - } - - /* - * Skip if table belongs to a not requested database. - */ - if (tabhash == NULL) - break; - - tabentry = (PgStat_StatTabEntry *) hash_search(tabhash, - (void *) &tabbuf.tableid, - HASH_ENTER, &found); - if (tabentry == NULL) - { - if (pgStatRunningInCollector) - { - elog(LOG, "PGSTAT: Tab hash table out of memory"); - exit(1); - } - else - { - fclose(fpin); - elog(ERROR, "PGSTAT: Tab hash table out of memory"); - } - } - - if (found) - { - if (pgStatRunningInCollector) - { - elog(LOG, "PGSTAT: corrupted pgstat.stat file"); - fclose(fpin); - return; - } - else - { - elog(WARNING, "PGSTAT: corrupted pgstat.stat file"); - fclose(fpin); - return; - } - } - - memcpy(tabentry, &tabbuf, sizeof(tabbuf)); - break; - - /* - * 'M' The maximum number of backends to expect follows. - */ - case 'M': - if (betab == NULL || numbackends == NULL) - { - fclose(fpin); - return; - } - if (fread(&maxbackends, 1, sizeof(maxbackends), fpin) != - sizeof(maxbackends)) - { - if (pgStatRunningInCollector) - { - elog(LOG, "PGSTAT: corrupted pgstat.stat file"); - fclose(fpin); - return; - } - else - { - elog(WARNING, "PGSTAT: corrupted pgstat.stat file"); - fclose(fpin); - return; - } - } - if (maxbackends == 0) - { - fclose(fpin); - return; - } - - /* - * Allocate space (in TopTransactionContext too) for the - * backend table. - */ - if (use_mcxt == NULL) - *betab = (PgStat_StatBeEntry *) malloc( - sizeof(PgStat_StatBeEntry) * maxbackends); - else - *betab = (PgStat_StatBeEntry *) MemoryContextAlloc( - use_mcxt, - sizeof(PgStat_StatBeEntry) * maxbackends); - break; - - /* - * 'B' A PgStat_StatBeEntry follows. - */ - case 'B': - if (betab == NULL || numbackends == NULL) - { - fclose(fpin); - return; - } - if (*betab == NULL) - { - fclose(fpin); - return; - } - - /* - * Read it directly into the table. - */ - if (fread(&(*betab)[havebackends], 1, - sizeof(PgStat_StatBeEntry), fpin) != - sizeof(PgStat_StatBeEntry)) - { - if (pgStatRunningInCollector) - { - elog(LOG, "PGSTAT: corrupted pgstat.stat file"); - fclose(fpin); - return; - } - else - { - elog(WARNING, "PGSTAT: corrupted pgstat.stat file"); - fclose(fpin); - return; - } - } - - /* - * Count backends per database here. - */ - dbentry = (PgStat_StatDBEntry *) hash_search(*dbhash, - (void *) &((*betab)[havebackends].databaseid), - HASH_FIND, NULL); - if (dbentry) - dbentry->n_backends++; - - havebackends++; - if (numbackends != 0) - *numbackends = havebackends; - if (havebackends >= maxbackends) - { - fclose(fpin); - return; - } - break; - - /* - * 'E' The EOF marker of a complete stats file. - */ - case 'E': - fclose(fpin); - return; - - default: - if (pgStatRunningInCollector) - { - elog(LOG, "PGSTAT: corrupted pgstat.stat file"); - fclose(fpin); - return; - } - else - { - elog(WARNING, "PGSTAT: corrupted pgstat.stat file"); - fclose(fpin); - return; - } - } - } - - fclose(fpin); -} - - -/* ---------- - * pgstat_recv_bestart() - - * - * Process a backend starup message. - * ---------- - */ -static void -pgstat_recv_bestart(PgStat_MsgBestart *msg, int len) -{ - pgstat_add_backend(&msg->m_hdr); -} - - -/* ---------- - * pgstat_recv_beterm() - - * - * Process a backend termination message. - * ---------- - */ -static void -pgstat_recv_beterm(PgStat_MsgBeterm *msg, int len) -{ - pgstat_sub_backend(msg->m_hdr.m_procpid); -} - - -/* ---------- - * pgstat_recv_activity() - - * - * Remember what the backend is doing. - * ---------- - */ -static void -pgstat_recv_activity(PgStat_MsgActivity *msg, int len) -{ - /* - * Here we check explicitly for 0 return, since we don't want to - * mangle the activity of an active backend by a delayed packed from a - * dead one. - */ - if (pgstat_add_backend(&msg->m_hdr) != 0) - return; - - strncpy(pgStatBeTable[msg->m_hdr.m_backendid - 1].activity, - msg->m_what, PGSTAT_ACTIVITY_SIZE); -} - - -/* ---------- - * pgstat_recv_tabstat() - - * - * Count what the backend has done. - * ---------- - */ -static void -pgstat_recv_tabstat(PgStat_MsgTabstat *msg, int len) -{ - PgStat_TableEntry *tabmsg = &(msg->m_entry[0]); - PgStat_StatDBEntry *dbentry; - PgStat_StatTabEntry *tabentry; - int i; - bool found; - - /* - * Make sure the backend is counted for. - */ - if (pgstat_add_backend(&msg->m_hdr) < 0) - return; - - /* - * Lookup the database in the hashtable. - */ - dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash, - (void *) &(msg->m_hdr.m_databaseid), - HASH_FIND, NULL); - if (!dbentry) - return; - - /* - * If the database is marked for destroy, this is a delayed UDP packet - * and not worth being counted. - */ - if (dbentry->destroy > 0) - return; - - dbentry->n_xact_commit += (PgStat_Counter) (msg->m_xact_commit); - dbentry->n_xact_rollback += (PgStat_Counter) (msg->m_xact_rollback); - - /* - * Process all table entries in the message. - */ - for (i = 0; i < msg->m_nentries; i++) - { - tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables, - (void *) &(tabmsg[i].t_id), - HASH_ENTER, &found); - if (tabentry == NULL) - { - elog(LOG, "PGSTAT: tables hash table out of memory for " - "database %d - abort", dbentry->databaseid); - exit(1); - } - - if (!found) - { - /* - * If it's a new table entry, initialize counters to the - * values we just got. - */ - tabentry->numscans = tabmsg[i].t_numscans; - tabentry->tuples_returned = tabmsg[i].t_tuples_returned; - tabentry->tuples_fetched = tabmsg[i].t_tuples_fetched; - tabentry->tuples_inserted = tabmsg[i].t_tuples_inserted; - tabentry->tuples_updated = tabmsg[i].t_tuples_updated; - tabentry->tuples_deleted = tabmsg[i].t_tuples_deleted; - tabentry->blocks_fetched = tabmsg[i].t_blocks_fetched; - tabentry->blocks_hit = tabmsg[i].t_blocks_hit; - - tabentry->destroy = 0; - } - else - { - /* - * Otherwise add the values to the existing entry. - */ - tabentry->numscans += tabmsg[i].t_numscans; - tabentry->tuples_returned += tabmsg[i].t_tuples_returned; - tabentry->tuples_fetched += tabmsg[i].t_tuples_fetched; - tabentry->tuples_inserted += tabmsg[i].t_tuples_inserted; - tabentry->tuples_updated += tabmsg[i].t_tuples_updated; - tabentry->tuples_deleted += tabmsg[i].t_tuples_deleted; - tabentry->blocks_fetched += tabmsg[i].t_blocks_fetched; - tabentry->blocks_hit += tabmsg[i].t_blocks_hit; - } - - /* - * And add the block IO to the database entry. - */ - dbentry->n_blocks_fetched += tabmsg[i].t_blocks_fetched; - dbentry->n_blocks_hit += tabmsg[i].t_blocks_hit; - } -} - - -/* ---------- - * pgstat_recv_tabpurge() - - * - * Arrange for dead table removal. - * ---------- - */ -static void -pgstat_recv_tabpurge(PgStat_MsgTabpurge *msg, int len) -{ - PgStat_StatDBEntry *dbentry; - PgStat_StatTabEntry *tabentry; - int i; - - /* - * Make sure the backend is counted for. - */ - if (pgstat_add_backend(&msg->m_hdr) < 0) - return; - - /* - * Lookup the database in the hashtable. - */ - dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash, - (void *) &(msg->m_hdr.m_databaseid), - HASH_FIND, NULL); - if (!dbentry) - return; - - /* - * If the database is marked for destroy, this is a delayed UDP packet - * and the tables will go away at DB destruction. - */ - if (dbentry->destroy > 0) - return; - - /* - * Process all table entries in the message. - */ - for (i = 0; i < msg->m_nentries; i++) - { - tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables, - (void *) &(msg->m_tableid[i]), - HASH_FIND, NULL); - if (tabentry) - tabentry->destroy = PGSTAT_DESTROY_COUNT; - } -} - - -/* ---------- - * pgstat_recv_dropdb() - - * - * Arrange for dead database removal - * ---------- - */ -static void -pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len) -{ - PgStat_StatDBEntry *dbentry; - - /* - * Make sure the backend is counted for. - */ - if (pgstat_add_backend(&msg->m_hdr) < 0) - return; - - /* - * Lookup the database in the hashtable. - */ - dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash, - (void *) &(msg->m_databaseid), - HASH_FIND, NULL); - if (!dbentry) - return; - - /* - * Mark the database for destruction. - */ - dbentry->destroy = PGSTAT_DESTROY_COUNT; -} - - -/* ---------- - * pgstat_recv_dropdb() - - * - * Arrange for dead database removal - * ---------- - */ -static void -pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len) -{ - HASHCTL hash_ctl; - PgStat_StatDBEntry *dbentry; - - /* - * Make sure the backend is counted for. - */ - if (pgstat_add_backend(&msg->m_hdr) < 0) - return; - - /* - * Lookup the database in the hashtable. - */ - dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash, - (void *) &(msg->m_hdr.m_databaseid), - HASH_FIND, NULL); - if (!dbentry) - return; - - /* - * We simply throw away all the databases table entries by recreating - * a new hash table for them. - */ - if (dbentry->tables != NULL) - hash_destroy(dbentry->tables); - - dbentry->tables = NULL; - dbentry->n_xact_commit = 0; - dbentry->n_xact_rollback = 0; - dbentry->n_blocks_fetched = 0; - dbentry->n_blocks_hit = 0; - dbentry->n_connects = 0; - dbentry->destroy = 0; - - memset(&hash_ctl, 0, sizeof(hash_ctl)); - hash_ctl.keysize = sizeof(Oid); - hash_ctl.entrysize = sizeof(PgStat_StatTabEntry); - hash_ctl.hash = tag_hash; - dbentry->tables = hash_create("Per-database table", - PGSTAT_TAB_HASH_SIZE, - &hash_ctl, - HASH_ELEM | HASH_FUNCTION); - if (dbentry->tables == NULL) - { - elog(LOG, "PGSTAT: failed to reinitialize hash table for " - "database entry"); - exit(1); - } -} |