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postgres/src/backend/postmaster/pgstat.c
Alvaro Herrera 1f219cf433 Add last-vacuum/analyze-time columns to the stats collector, both manual and 
issued by autovacuum.  Add accessor functions to them, and use those in the
pg_stat_*_tables system views.

Catalog version bumped due to changes in the pgstat views and the pgstat file.

Patch from Larry Rosenman, minor improvements by me.
2006-05-19 19:08:27 +00:00

3190 lines
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/* ----------
* 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) 2001-2006, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.126 2006/05/19 19:08:26 alvherre Exp $
* ----------
*/
#include "postgres.h"
#include <unistd.h>
#include <fcntl.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>
#include <time.h>
#include <sys/stat.h>
#include "pgstat.h"
#include "access/heapam.h"
#include "access/xact.h"
#include "catalog/pg_database.h"
#include "libpq/libpq.h"
#include "libpq/pqsignal.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "postmaster/autovacuum.h"
#include "postmaster/fork_process.h"
#include "postmaster/postmaster.h"
#include "storage/backendid.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/pg_shmem.h"
#include "storage/pmsignal.h"
#include "storage/procarray.h"
#include "tcop/tcopprot.h"
#include "utils/hsearch.h"
#include "utils/memutils.h"
#include "utils/ps_status.h"
#include "utils/rel.h"
#include "utils/syscache.h"
/* ----------
* Paths for the statistics files (relative to installation's $PGDATA).
* ----------
*/
#define PGSTAT_STAT_FILENAME "global/pgstat.stat"
#define PGSTAT_STAT_TMPFILE "global/pgstat.tmp"
/* ----------
* Timer definitions.
* ----------
*/
/* How often to write the status file, in milliseconds. */
#define PGSTAT_STAT_INTERVAL (5*60*1000)
/*
* How often to attempt to restart a failed statistics collector; in ms.
* Must be at least PGSTAT_STAT_INTERVAL.
*/
#define PGSTAT_RESTART_INTERVAL (5*60*1000)
/* ----------
* Amount of space reserved in pgstat_recvbuffer().
* ----------
*/
#define PGSTAT_RECVBUFFERSZ ((int) (1024 * sizeof(PgStat_Msg)))
/* ----------
* The initial size hints for the hash tables used in the collector.
* ----------
*/
#define PGSTAT_DB_HASH_SIZE 16
#define PGSTAT_BE_HASH_SIZE 512
#define PGSTAT_TAB_HASH_SIZE 512
/* ----------
* GUC parameters
* ----------
*/
bool pgstat_collect_startcollector = true;
bool pgstat_collect_resetonpmstart = false;
bool pgstat_collect_querystring = false;
bool pgstat_collect_tuplelevel = false;
bool pgstat_collect_blocklevel = false;
/* ----------
* Local data
* ----------
*/
NON_EXEC_STATIC int pgStatSock = -1;
NON_EXEC_STATIC int pgStatPipe[2] = {-1, -1};
static struct sockaddr_storage pgStatAddr;
static pid_t pgStatCollectorPid = 0;
static time_t last_pgstat_start_time;
static long pgStatNumMessages = 0;
static bool pgStatRunningInCollector = false;
/*
* Place where backends store per-table info to be sent to the collector.
* We store shared relations separately from non-shared ones, to be able to
* send them in separate messages.
*/
typedef struct TabStatArray
{
int tsa_alloc; /* num allocated */
int tsa_used; /* num actually used */
PgStat_MsgTabstat **tsa_messages; /* the array itself */
} TabStatArray;
#define TABSTAT_QUANTUM 4 /* we alloc this many at a time */
static TabStatArray RegularTabStat = {0, 0, NULL};
static TabStatArray SharedTabStat = {0, 0, NULL};
static int pgStatXactCommit = 0;
static int pgStatXactRollback = 0;
static TransactionId pgStatDBHashXact = InvalidTransactionId;
static HTAB *pgStatDBHash = NULL;
static PgStat_StatBeEntry *pgStatBeTable = NULL;
static int pgStatNumBackends = 0;
static volatile bool need_statwrite;
/* ----------
* Local function forward declarations
* ----------
*/
#ifdef EXEC_BACKEND
typedef enum STATS_PROCESS_TYPE
{
STAT_PROC_BUFFER,
STAT_PROC_COLLECTOR
} STATS_PROCESS_TYPE;
static pid_t pgstat_forkexec(STATS_PROCESS_TYPE procType);
static void pgstat_parseArgs(int argc, char *argv[]);
#endif
NON_EXEC_STATIC void PgstatBufferMain(int argc, char *argv[]);
NON_EXEC_STATIC void PgstatCollectorMain(int argc, char *argv[]);
static void force_statwrite(SIGNAL_ARGS);
static void pgstat_recvbuffer(void);
static void pgstat_exit(SIGNAL_ARGS);
static void pgstat_die(SIGNAL_ARGS);
static void pgstat_beshutdown_hook(int code, Datum arg);
static PgStat_StatDBEntry *pgstat_get_db_entry(Oid databaseid, bool create);
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, bool rewrite);
static void backend_read_statsfile(void);
static void pgstat_setheader(PgStat_MsgHdr *hdr, StatMsgType mtype);
static void pgstat_send(void *msg, int len);
static void pgstat_send_rewrite(void);
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);
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);
/* ------------------------------------------------------------
* Public functions called from postmaster follow
* ------------------------------------------------------------
*/
/* ----------
* pgstat_init() -
*
* Called from postmaster at startup. Create the resources required
* by the statistics collector process. If unable to do so, do not
* fail --- better to let the postmaster start with stats collection
* disabled.
* ----------
*/
void
pgstat_init(void)
{
ACCEPT_TYPE_ARG3 alen;
struct addrinfo *addrs = NULL,
*addr,
hints;
int ret;
fd_set rset;
struct timeval tv;
char test_byte;
int sel_res;
int tries = 0;
#define TESTBYTEVAL ((char) 199)
/*
* Force start of collector daemon if something to collect
*/
if (pgstat_collect_querystring ||
pgstat_collect_tuplelevel ||
pgstat_collect_blocklevel)
pgstat_collect_startcollector = true;
/*
* If we don't have to start a collector or should reset the collected
* statistics on postmaster start, simply remove the stats file.
*/
if (!pgstat_collect_startcollector || pgstat_collect_resetonpmstart)
pgstat_reset_all();
/*
* Nothing else required if collector will not get started
*/
if (!pgstat_collect_startcollector)
return;
/*
* Create the UDP socket for sending and receiving statistic messages
*/
hints.ai_flags = AI_PASSIVE;
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
hints.ai_protocol = 0;
hints.ai_addrlen = 0;
hints.ai_addr = NULL;
hints.ai_canonname = NULL;
hints.ai_next = NULL;
ret = pg_getaddrinfo_all("localhost", NULL, &hints, &addrs);
if (ret || !addrs)
{
ereport(LOG,
(errmsg("could not resolve \"localhost\": %s",
gai_strerror(ret))));
goto startup_failed;
}
/*
* On some platforms, pg_getaddrinfo_all() may return multiple addresses
* only one of which will actually work (eg, both IPv6 and IPv4 addresses
* when kernel will reject IPv6). Worse, the failure may occur at the
* bind() or perhaps even connect() stage. So we must loop through the
* results till we find a working combination. We will generate LOG
* messages, but no error, for bogus combinations.
*/
for (addr = addrs; addr; addr = addr->ai_next)
{
#ifdef HAVE_UNIX_SOCKETS
/* Ignore AF_UNIX sockets, if any are returned. */
if (addr->ai_family == AF_UNIX)
continue;
#endif
if (++tries > 1)
ereport(LOG,
(errmsg("trying another address for the statistics collector")));
/*
* Create the socket.
*/
if ((pgStatSock = socket(addr->ai_family, SOCK_DGRAM, 0)) < 0)
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("could not create socket for statistics collector: %m")));
continue;
}
/*
* Bind it to a kernel assigned port on localhost and get the assigned
* port via getsockname().
*/
if (bind(pgStatSock, addr->ai_addr, addr->ai_addrlen) < 0)
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("could not bind socket for statistics collector: %m")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
alen = sizeof(pgStatAddr);
if (getsockname(pgStatSock, (struct sockaddr *) & pgStatAddr, &alen) < 0)
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("could not get address of socket for statistics collector: %m")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
/*
* Connect the socket to its own address. This saves a few cycles by
* not having to respecify the target address on every send. This also
* provides a kernel-level check that only packets from this same
* address will be received.
*/
if (connect(pgStatSock, (struct sockaddr *) & pgStatAddr, alen) < 0)
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("could not connect socket for statistics collector: %m")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
/*
* Try to send and receive a one-byte test message on the socket. This
* is to catch situations where the socket can be created but will not
* actually pass data (for instance, because kernel packet filtering
* rules prevent it).
*/
test_byte = TESTBYTEVAL;
if (send(pgStatSock, &test_byte, 1, 0) != 1)
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("could not send test message on socket for statistics collector: %m")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
/*
* There could possibly be a little delay before the message can be
* received. We arbitrarily allow up to half a second before deciding
* it's broken.
*/
for (;;) /* need a loop to handle EINTR */
{
FD_ZERO(&rset);
FD_SET(pgStatSock, &rset);
tv.tv_sec = 0;
tv.tv_usec = 500000;
sel_res = select(pgStatSock + 1, &rset, NULL, NULL, &tv);
if (sel_res >= 0 || errno != EINTR)
break;
}
if (sel_res < 0)
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("select() failed in statistics collector: %m")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
if (sel_res == 0 || !FD_ISSET(pgStatSock, &rset))
{
/*
* This is the case we actually think is likely, so take pains to
* give a specific message for it.
*
* errno will not be set meaningfully here, so don't use it.
*/
ereport(LOG,
(errcode(ERRCODE_CONNECTION_FAILURE),
errmsg("test message did not get through on socket for statistics collector")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
test_byte++; /* just make sure variable is changed */
if (recv(pgStatSock, &test_byte, 1, 0) != 1)
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("could not receive test message on socket for statistics collector: %m")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
if (test_byte != TESTBYTEVAL) /* strictly paranoia ... */
{
ereport(LOG,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg("incorrect test message transmission on socket for statistics collector")));
closesocket(pgStatSock);
pgStatSock = -1;
continue;
}
/* If we get here, we have a working socket */
break;
}
/* Did we find a working address? */
if (!addr || pgStatSock < 0)
goto startup_failed;
/*
* Set the socket to non-blocking IO. This ensures that if the collector
* falls behind (despite the buffering process), statistics messages will
* be discarded; backends won't block waiting to send messages to the
* collector.
*/
if (!pg_set_noblock(pgStatSock))
{
ereport(LOG,
(errcode_for_socket_access(),
errmsg("could not set statistics collector socket to nonblocking mode: %m")));
goto startup_failed;
}
pg_freeaddrinfo_all(hints.ai_family, addrs);
return;
startup_failed:
ereport(LOG,
(errmsg("disabling statistics collector for lack of working socket")));
if (addrs)
pg_freeaddrinfo_all(hints.ai_family, addrs);
if (pgStatSock >= 0)
closesocket(pgStatSock);
pgStatSock = -1;
/* Adjust GUC variables to suppress useless activity */
pgstat_collect_startcollector = false;
pgstat_collect_querystring = false;
pgstat_collect_tuplelevel = false;
pgstat_collect_blocklevel = false;
}
/*
* pgstat_reset_all() -
*
* Remove the stats file. This is used on server start if the
* stats_reset_on_server_start feature is enabled, or if WAL
* recovery is needed after a crash.
*/
void
pgstat_reset_all(void)
{
unlink(PGSTAT_STAT_FILENAME);
}
#ifdef EXEC_BACKEND
/*
* pgstat_forkexec() -
*
* Format up the arglist for, then fork and exec, statistics
* (buffer and collector) processes
*/
static pid_t
pgstat_forkexec(STATS_PROCESS_TYPE procType)
{
char *av[10];
int ac = 0,
bufc = 0,
i;
char pgstatBuf[2][32];
av[ac++] = "postgres";
switch (procType)
{
case STAT_PROC_BUFFER:
av[ac++] = "-forkbuf";
break;
case STAT_PROC_COLLECTOR:
av[ac++] = "-forkcol";
break;
default:
Assert(false);
}
av[ac++] = NULL; /* filled in by postmaster_forkexec */
/* postgres_exec_path is not passed by write_backend_variables */
av[ac++] = postgres_exec_path;
/* Add to the arg list */
Assert(bufc <= lengthof(pgstatBuf));
for (i = 0; i < bufc; i++)
av[ac++] = pgstatBuf[i];
av[ac] = NULL;
Assert(ac < lengthof(av));
return postmaster_forkexec(ac, av);
}
/*
* pgstat_parseArgs() -
*
* Extract data from the arglist for exec'ed statistics
* (buffer and collector) processes
*/
static void
pgstat_parseArgs(int argc, char *argv[])
{
Assert(argc == 4);
argc = 3;
StrNCpy(postgres_exec_path, argv[argc++], MAXPGPATH);
}
#endif /* EXEC_BACKEND */
/* ----------
* pgstat_start() -
*
* Called from postmaster at startup or after an existing collector
* died. Attempt to fire up a fresh statistics collector.
*
* Returns PID of child process, or 0 if fail.
*
* Note: if fail, we will be called again from the postmaster main loop.
* ----------
*/
int
pgstat_start(void)
{
time_t curtime;
pid_t pgStatPid;
/*
* Do nothing if no collector needed
*/
if (!pgstat_collect_startcollector)
return 0;
/*
* Do nothing if too soon since last collector start. This is a safety
* valve to protect against continuous respawn attempts if the collector
* is dying immediately at launch. Note that since we will be re-called
* from the postmaster main loop, we will get another chance later.
*/
curtime = time(NULL);
if ((unsigned int) (curtime - last_pgstat_start_time) <
(unsigned int) PGSTAT_RESTART_INTERVAL)
return 0;
last_pgstat_start_time = curtime;
/*
* Check that the socket is there, else pgstat_init failed.
*/
if (pgStatSock < 0)
{
ereport(LOG,
(errmsg("statistics collector startup skipped")));
/*
* We can only get here if someone tries to manually turn
* pgstat_collect_startcollector on after it had been off.
*/
pgstat_collect_startcollector = false;
return 0;
}
/*
* Okay, fork off the collector.
*/
#ifdef EXEC_BACKEND
switch ((pgStatPid = pgstat_forkexec(STAT_PROC_BUFFER)))
#else
switch ((pgStatPid = fork_process()))
#endif
{
case -1:
ereport(LOG,
(errmsg("could not fork statistics buffer: %m")));
return 0;
#ifndef EXEC_BACKEND
case 0:
/* in postmaster child ... */
/* Close the postmaster's sockets */
ClosePostmasterPorts(false);
/* Lose the postmaster's on-exit routines */
on_exit_reset();
/* Drop our connection to postmaster's shared memory, as well */
PGSharedMemoryDetach();
PgstatBufferMain(0, NULL);
break;
#endif
default:
return (int) pgStatPid;
}
/* shouldn't get here */
return 0;
}
/* ----------
* pgstat_beterm() -
*
* Called from postmaster to tell collector a backend terminated.
* ----------
*/
void
pgstat_beterm(int pid)
{
PgStat_MsgBeterm msg;
if (pgStatSock < 0)
return;
/* can't use pgstat_setheader() because it's not called in a backend */
MemSet(&(msg.m_hdr), 0, sizeof(msg.m_hdr));
msg.m_hdr.m_type = PGSTAT_MTYPE_BETERM;
msg.m_hdr.m_procpid = pid;
pgstat_send(&msg, sizeof(msg));
}
/* ----------
* pgstat_report_autovac() -
*
* Called from autovacuum.c to report startup of an autovacuum process.
* We are called before InitPostgres is done, so can't rely on MyDatabaseId;
* the db OID must be passed in, instead.
* ----------
*/
void
pgstat_report_autovac(Oid dboid)
{
PgStat_MsgAutovacStart msg;
if (pgStatSock < 0)
return;
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_AUTOVAC_START);
msg.m_databaseid = dboid;
msg.m_start_time = GetCurrentTimestamp();
pgstat_send(&msg, sizeof(msg));
}
/* ------------------------------------------------------------
* Public functions used by backends follow
*------------------------------------------------------------
*/
/* ----------
* pgstat_bestart() -
*
* Tell the collector that this new backend is soon ready to process
* queries. Called from InitPostgres.
* ----------
*/
void
pgstat_bestart(void)
{
PgStat_MsgBestart msg;
if (pgStatSock < 0)
return;
/*
* We may not have a MyProcPort (eg, if this is the autovacuum process).
* Send an all-zeroes client address, which is dealt with specially in
* pg_stat_get_backend_client_addr and pg_stat_get_backend_client_port.
*/
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_BESTART);
msg.m_databaseid = MyDatabaseId;
msg.m_userid = GetSessionUserId();
if (MyProcPort)
memcpy(&msg.m_clientaddr, &MyProcPort->raddr, sizeof(msg.m_clientaddr));
else
MemSet(&msg.m_clientaddr, 0, sizeof(msg.m_clientaddr));
pgstat_send(&msg, sizeof(msg));
/*
* Set up a process-exit hook to ensure we flush the last batch of
* statistics to the collector.
*/
on_shmem_exit(pgstat_beshutdown_hook, 0);
}
/* ---------
* pgstat_report_vacuum() -
*
* Tell the collector about the table we just vacuumed.
* ---------
*/
void
pgstat_report_vacuum(Oid tableoid, bool shared,
bool analyze, PgStat_Counter tuples)
{
PgStat_MsgVacuum msg;
if (pgStatSock < 0 ||
!pgstat_collect_tuplelevel)
return;
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_VACUUM);
msg.m_databaseid = shared ? InvalidOid : MyDatabaseId;
msg.m_tableoid = tableoid;
msg.m_analyze = analyze;
msg.m_autovacuum = IsAutoVacuumProcess(); /* is this autovacuum? */
msg.m_vacuumtime = GetCurrentTimestamp();
msg.m_tuples = tuples;
pgstat_send(&msg, sizeof(msg));
}
/* --------
* pgstat_report_analyze() -
*
* Tell the collector about the table we just analyzed.
* --------
*/
void
pgstat_report_analyze(Oid tableoid, bool shared, PgStat_Counter livetuples,
PgStat_Counter deadtuples)
{
PgStat_MsgAnalyze msg;
if (pgStatSock < 0 ||
!pgstat_collect_tuplelevel)
return;
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_ANALYZE);
msg.m_databaseid = shared ? InvalidOid : MyDatabaseId;
msg.m_tableoid = tableoid;
msg.m_autovacuum = IsAutoVacuumProcess(); /* is this autovacuum? */
msg.m_analyzetime = GetCurrentTimestamp();
msg.m_live_tuples = livetuples;
msg.m_dead_tuples = deadtuples;
pgstat_send(&msg, sizeof(msg));
}
/*
* Flush any remaining statistics counts out to the collector at process
* exit. Without this, operations triggered during backend exit (such as
* temp table deletions) won't be counted.
*/
static void
pgstat_beshutdown_hook(int code, Datum arg)
{
pgstat_report_tabstat();
}
/* ----------
* pgstat_report_activity() -
*
* Called from 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(const char *cmd_str)
{
PgStat_MsgActivity msg;
int len;
if (!pgstat_collect_querystring || pgStatSock < 0)
return;
len = strlen(cmd_str);
len = pg_mbcliplen(cmd_str, len, PGSTAT_ACTIVITY_SIZE - 1);
memcpy(msg.m_cmd_str, cmd_str, len);
msg.m_cmd_str[len] = '\0';
len += offsetof(PgStat_MsgActivity, m_cmd_str) + 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;
if (pgStatSock < 0 ||
(!pgstat_collect_querystring &&
!pgstat_collect_tuplelevel &&
!pgstat_collect_blocklevel))
{
/* Not reporting stats, so just flush whatever we have */
RegularTabStat.tsa_used = 0;
SharedTabStat.tsa_used = 0;
return;
}
/*
* For each message buffer used during the last query set the header
* fields and send it out.
*/
for (i = 0; i < RegularTabStat.tsa_used; i++)
{
PgStat_MsgTabstat *tsmsg = RegularTabStat.tsa_messages[i];
int n;
int len;
n = tsmsg->m_nentries;
len = offsetof(PgStat_MsgTabstat, m_entry[0]) +
n * sizeof(PgStat_TableEntry);
tsmsg->m_xact_commit = pgStatXactCommit;
tsmsg->m_xact_rollback = pgStatXactRollback;
pgStatXactCommit = 0;
pgStatXactRollback = 0;
pgstat_setheader(&tsmsg->m_hdr, PGSTAT_MTYPE_TABSTAT);
tsmsg->m_databaseid = MyDatabaseId;
pgstat_send(tsmsg, len);
}
RegularTabStat.tsa_used = 0;
/* Ditto, for shared relations */
for (i = 0; i < SharedTabStat.tsa_used; i++)
{
PgStat_MsgTabstat *tsmsg = SharedTabStat.tsa_messages[i];
int n;
int len;
n = tsmsg->m_nentries;
len = offsetof(PgStat_MsgTabstat, m_entry[0]) +
n * sizeof(PgStat_TableEntry);
/* We don't report transaction commit/abort here */
tsmsg->m_xact_commit = 0;
tsmsg->m_xact_rollback = 0;
pgstat_setheader(&tsmsg->m_hdr, PGSTAT_MTYPE_TABSTAT);
tsmsg->m_databaseid = InvalidOid;
pgstat_send(tsmsg, len);
}
SharedTabStat.tsa_used = 0;
}
/* ----------
* pgstat_vacuum_tabstat() -
*
* Will tell the collector about objects he can get rid of.
* ----------
*/
void
pgstat_vacuum_tabstat(void)
{
List *oidlist;
Relation rel;
HeapScanDesc scan;
HeapTuple tup;
PgStat_MsgTabpurge msg;
HASH_SEQ_STATUS hstat;
PgStat_StatDBEntry *dbentry;
PgStat_StatTabEntry *tabentry;
int len;
if (pgStatSock < 0)
return;
/*
* If not done for this transaction, read the statistics collector stats
* file into some hash tables.
*/
backend_read_statsfile();
/*
* Read pg_database and make a list of OIDs of all existing databases
*/
oidlist = NIL;
rel = heap_open(DatabaseRelationId, AccessShareLock);
scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
while ((tup = heap_getnext(scan, ForwardScanDirection)) != NULL)
{
oidlist = lappend_oid(oidlist, HeapTupleGetOid(tup));
}
heap_endscan(scan);
heap_close(rel, AccessShareLock);
/*
* 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;
if (!list_member_oid(oidlist, dbid))
pgstat_drop_database(dbid);
}
/* Clean up */
list_free(oidlist);
/*
* 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.
*/
oidlist = NIL;
rel = heap_open(RelationRelationId, AccessShareLock);
scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
while ((tup = heap_getnext(scan, ForwardScanDirection)) != NULL)
{
oidlist = lappend_oid(oidlist, HeapTupleGetOid(tup));
}
heap_endscan(scan);
heap_close(rel, AccessShareLock);
/*
* 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)
{
if (list_member_oid(oidlist, tabentry->tableid))
continue;
/*
* Not there, so add this table's Oid to the message
*/
msg.m_tableid[msg.m_nentries++] = tabentry->tableid;
/*
* 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 */
list_free(oidlist);
}
/* ----------
* pgstat_drop_database() -
*
* Tell the collector that we just dropped a database.
* (If the message gets lost, we will still clean the dead DB eventually
* via future invocations of pgstat_vacuum_tabstat().)
* ----------
*/
static void
pgstat_drop_database(Oid databaseid)
{
PgStat_MsgDropdb msg;
if (pgStatSock < 0)
return;
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_DROPDB);
msg.m_databaseid = databaseid;
pgstat_send(&msg, sizeof(msg));
}
/* ----------
* pgstat_drop_relation() -
*
* Tell the collector that we just dropped a relation.
* (If the message gets lost, we will still clean the dead entry eventually
* via future invocations of pgstat_vacuum_tabstat().)
* ----------
*/
void
pgstat_drop_relation(Oid relid)
{
PgStat_MsgTabpurge msg;
int len;
if (pgStatSock < 0)
return;
msg.m_tableid[0] = relid;
msg.m_nentries = 1;
len = offsetof(PgStat_MsgTabpurge, m_tableid[0]) + sizeof(Oid);
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TABPURGE);
msg.m_databaseid = MyDatabaseId;
pgstat_send(&msg, len);
}
/* ----------
* pgstat_reset_counters() -
*
* Tell the statistics collector to reset counters for our database.
* ----------
*/
void
pgstat_reset_counters(void)
{
PgStat_MsgResetcounter msg;
if (pgStatSock < 0)
return;
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to reset statistics counters")));
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_RESETCOUNTER);
msg.m_databaseid = MyDatabaseId;
pgstat_send(&msg, sizeof(msg));
}
/* ----------
* pgstat_ping() -
*
* Send some junk data to the collector to increase traffic.
* ----------
*/
void
pgstat_ping(void)
{
PgStat_MsgDummy msg;
if (pgStatSock < 0)
return;
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_DUMMY);
pgstat_send(&msg, sizeof(msg));
}
/*
* Enlarge a TabStatArray
*/
static void
more_tabstat_space(TabStatArray *tsarr)
{
PgStat_MsgTabstat *newMessages;
PgStat_MsgTabstat **msgArray;
int newAlloc;
int i;
AssertArg(PointerIsValid(tsarr));
newAlloc = tsarr->tsa_alloc + TABSTAT_QUANTUM;
/* Create (another) quantum of message buffers */
newMessages = (PgStat_MsgTabstat *)
MemoryContextAllocZero(TopMemoryContext,
sizeof(PgStat_MsgTabstat) * TABSTAT_QUANTUM);
/* Create or enlarge the pointer array */
if (tsarr->tsa_messages == NULL)
msgArray = (PgStat_MsgTabstat **)
MemoryContextAlloc(TopMemoryContext,
sizeof(PgStat_MsgTabstat *) * newAlloc);
else
msgArray = (PgStat_MsgTabstat **)
repalloc(tsarr->tsa_messages,
sizeof(PgStat_MsgTabstat *) * newAlloc);
for (i = 0; i < TABSTAT_QUANTUM; i++)
msgArray[tsarr->tsa_alloc + i] = newMessages++;
tsarr->tsa_messages = msgArray;
tsarr->tsa_alloc = newAlloc;
Assert(tsarr->tsa_used < tsarr->tsa_alloc);
}
/* ----------
* pgstat_initstats() -
*
* Called from various places usually dealing with initialization
* of Relation or Scan structures. The data placed into these
* structures from here tell where later to count for buffer reads,
* scans and tuples fetched.
* ----------
*/
void
pgstat_initstats(PgStat_Info *stats, Relation rel)
{
Oid rel_id = rel->rd_id;
PgStat_TableEntry *useent;
TabStatArray *tsarr;
PgStat_MsgTabstat *tsmsg;
int mb;
int i;
/*
* Initialize data not to count at all.
*/
stats->tabentry = NULL;
if (pgStatSock < 0 ||
!(pgstat_collect_tuplelevel ||
pgstat_collect_blocklevel))
return;
tsarr = rel->rd_rel->relisshared ? &SharedTabStat : &RegularTabStat;
/*
* Search the already-used message slots for this relation.
*/
for (mb = 0; mb < tsarr->tsa_used; mb++)
{
tsmsg = tsarr->tsa_messages[mb];
for (i = tsmsg->m_nentries; --i >= 0;)
{
if (tsmsg->m_entry[i].t_id == rel_id)
{
stats->tabentry = (void *) &(tsmsg->m_entry[i]);
return;
}
}
if (tsmsg->m_nentries >= PGSTAT_NUM_TABENTRIES)
continue;
/*
* Not found, but found a message buffer with an empty slot instead.
* Fine, let's use this one.
*/
i = tsmsg->m_nentries++;
useent = &tsmsg->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 (tsarr->tsa_used >= tsarr->tsa_alloc)
more_tabstat_space(tsarr);
/*
* Use the first entry of the next message buffer.
*/
mb = tsarr->tsa_used++;
tsmsg = tsarr->tsa_messages[mb];
tsmsg->m_nentries = 1;
useent = &tsmsg->m_entry[0];
MemSet(useent, 0, sizeof(PgStat_TableEntry));
useent->t_id = rel_id;
stats->tabentry = (void *) useent;
}
/* ----------
* 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 (RegularTabStat.tsa_alloc == 0)
more_tabstat_space(&RegularTabStat);
if (RegularTabStat.tsa_used == 0)
{
RegularTabStat.tsa_used++;
RegularTabStat.tsa_messages[0]->m_nentries = 0;
}
}
/* ----------
* pgstat_count_xact_rollback() -
*
* Called from access/transam/xact.c to count transaction rollbacks.
* ----------
*/
void
pgstat_count_xact_rollback(void)
{
if (!pgstat_collect_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 (RegularTabStat.tsa_alloc == 0)
more_tabstat_space(&RegularTabStat);
if (RegularTabStat.tsa_used == 0)
{
RegularTabStat.tsa_used++;
RegularTabStat.tsa_messages[0]->m_nentries = 0;
}
}
/* ----------
* pgstat_fetch_stat_dbentry() -
*
* Support function for the SQL-callable pgstat* functions. Returns
* the collected statistics for one database or NULL. NULL doesn't mean
* that the database doesn't exist, it is just not yet known by the
* collector, so the caller is better off to report ZERO instead.
* ----------
*/
PgStat_StatDBEntry *
pgstat_fetch_stat_dbentry(Oid dbid)
{
/*
* If not done for this transaction, read the statistics collector stats
* file into some hash tables.
*/
backend_read_statsfile();
/*
* Lookup the requested database; return NULL if not found
*/
return (PgStat_StatDBEntry *) hash_search(pgStatDBHash,
(void *) &dbid,
HASH_FIND, NULL);
}
/* ----------
* pgstat_fetch_stat_tabentry() -
*
* Support function for the SQL-callable pgstat* functions. Returns
* the collected statistics for one table or NULL. NULL doesn't mean
* that the table doesn't exist, it is just not yet known by the
* collector, so the caller is better off to report ZERO instead.
* ----------
*/
PgStat_StatTabEntry *
pgstat_fetch_stat_tabentry(Oid relid)
{
Oid dbid;
PgStat_StatDBEntry *dbentry;
PgStat_StatTabEntry *tabentry;
/*
* If not done for this transaction, read the statistics collector stats
* file into some hash tables.
*/
backend_read_statsfile();
/*
* Lookup our database, then look in its table hash table.
*/
dbid = MyDatabaseId;
dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash,
(void *) &dbid,
HASH_FIND, NULL);
if (dbentry != NULL && dbentry->tables != NULL)
{
tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables,
(void *) &relid,
HASH_FIND, NULL);
if (tabentry)
return tabentry;
}
/*
* If we didn't find it, maybe it's a shared table.
*/
dbid = InvalidOid;
dbentry = (PgStat_StatDBEntry *) hash_search(pgStatDBHash,
(void *) &dbid,
HASH_FIND, NULL);
if (dbentry != NULL && dbentry->tables != NULL)
{
tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables,
(void *) &relid,
HASH_FIND, NULL);
if (tabentry)
return tabentry;
}
return NULL;
}
/* ----------
* pgstat_fetch_stat_beentry() -
*
* Support function for the SQL-callable pgstat* functions. Returns
* 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)
{
backend_read_statsfile();
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)
{
backend_read_statsfile();
return pgStatNumBackends;
}
/* ------------------------------------------------------------
* Local support functions follow
* ------------------------------------------------------------
*/
/* ----------
* pgstat_setheader() -
*
* Set common header fields in a statistics message
* ----------
*/
static void
pgstat_setheader(PgStat_MsgHdr *hdr, StatMsgType mtype)
{
hdr->m_type = mtype;
hdr->m_backendid = MyBackendId;
hdr->m_procpid = MyProcPid;
}
/* ----------
* 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;
#ifdef USE_ASSERT_CHECKING
if (send(pgStatSock, msg, len, 0) < 0)
elog(LOG, "could not send to statistics collector: %m");
#else
send(pgStatSock, msg, len, 0);
/* We deliberately ignore any error from send() */
#endif
}
/*
* pgstat_send_rewrite() -
*
* Send a command to the collector to rewrite the stats file.
* ----------
*/
static void
pgstat_send_rewrite(void)
{
PgStat_MsgRewrite msg;
if (pgStatSock < 0)
return;
pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_REWRITE);
pgstat_send(&msg, sizeof(msg));
}
/* ----------
* PgstatBufferMain() -
*
* Start up the statistics buffer 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
PgstatBufferMain(int argc, char *argv[])
{
IsUnderPostmaster = true; /* we are a postmaster subprocess now */
MyProcPid = getpid(); /* reset MyProcPid */
/*
* Ignore all signals usually bound to some action in the postmaster,
* except for SIGCHLD and SIGQUIT --- see pgstat_recvbuffer.
*/
pqsignal(SIGHUP, SIG_IGN);
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, SIG_IGN);
pqsignal(SIGQUIT, pgstat_exit);
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);
/* unblock will happen in pgstat_recvbuffer */
#ifdef EXEC_BACKEND
pgstat_parseArgs(argc, argv);
#endif
/*
* 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 (pgpipe(pgStatPipe) < 0)
ereport(ERROR,
(errcode_for_socket_access(),
errmsg("could not create pipe for statistics buffer: %m")));
/* child becomes collector process */
#ifdef EXEC_BACKEND
pgStatCollectorPid = pgstat_forkexec(STAT_PROC_COLLECTOR);
#else
pgStatCollectorPid = fork();
#endif
switch (pgStatCollectorPid)
{
case -1:
ereport(ERROR,
(errmsg("could not fork statistics collector: %m")));
#ifndef EXEC_BACKEND
case 0:
/* child becomes collector process */
PgstatCollectorMain(0, NULL);
break;
#endif
default:
/* parent becomes buffer process */
closesocket(pgStatPipe[0]);
pgstat_recvbuffer();
}
exit(0);
}
/* ----------
* PgstatCollectorMain() -
*
* Start up the statistics collector itself. This is the body of the
* postmaster grandchild process.
*
* The argc/argv parameters are valid only in EXEC_BACKEND case.
* ----------
*/
NON_EXEC_STATIC void
PgstatCollectorMain(int argc, char *argv[])
{
PgStat_Msg msg;
fd_set rfds;
int readPipe;
int len = 0;
struct itimerval timeout, canceltimeout;
bool need_timer = false;
MyProcPid = getpid(); /* reset MyProcPid */
/*
* Reset signal handling. With the exception of restoring default SIGCHLD
* and SIGQUIT handling, this is a no-op in the non-EXEC_BACKEND case
* because we'll have inherited these settings from the buffer process;
* but it's not a no-op for EXEC_BACKEND.
*/
pqsignal(SIGHUP, SIG_IGN);
pqsignal(SIGINT, SIG_IGN);
pqsignal(SIGTERM, SIG_IGN);
#ifndef WIN32
pqsignal(SIGQUIT, SIG_IGN);
#else
/* kluge to allow buffer process to kill collector; FIXME */
pqsignal(SIGQUIT, pgstat_exit);
#endif
pqsignal(SIGALRM, force_statwrite);
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, SIG_IGN);
pqsignal(SIGUSR2, SIG_IGN);
pqsignal(SIGCHLD, SIG_DFL);
pqsignal(SIGTTIN, SIG_DFL);
pqsignal(SIGTTOU, SIG_DFL);
pqsignal(SIGCONT, SIG_DFL);
pqsignal(SIGWINCH, SIG_DFL);
PG_SETMASK(&UnBlockSig);
#ifdef EXEC_BACKEND
pgstat_parseArgs(argc, argv);
#endif
/* Close unwanted files */
closesocket(pgStatPipe[1]);
closesocket(pgStatSock);
/*
* Identify myself via ps
*/
init_ps_display("stats collector process", "", "");
set_ps_display("");
/*
* Arrange to write the initial status file right away
*/
need_statwrite = true;
/* Preset the delay between status file writes */
MemSet(&timeout, 0, sizeof(struct itimerval));
timeout.it_value.tv_sec = PGSTAT_STAT_INTERVAL / 1000;
timeout.it_value.tv_usec = PGSTAT_STAT_INTERVAL % 1000;
/* Values set to zero will cancel the active timer */
MemSet(&canceltimeout, 0, sizeof(struct itimerval));
/*
* Read in an existing statistics stats file or initialize the stats to
* zero.
*/
pgStatRunningInCollector = true;
pgstat_read_statsfile(&pgStatDBHash, InvalidOid, NULL, NULL, false);
/*
* Create the known backends table
*/
pgStatBeTable = (PgStat_StatBeEntry *)
palloc0(sizeof(PgStat_StatBeEntry) * MaxBackends);
readPipe = pgStatPipe[0];
/*
* Process incoming messages and handle all the reporting stuff until
* there are no more messages.
*/
for (;;)
{
/*
* If time to write the stats file, do so. Note that the alarm
* interrupt isn't re-enabled immediately, but only after we next
* receive a stats message; so no cycles are wasted when there is
* nothing going on.
*/
if (need_statwrite)
{
pgstat_write_statsfile();
need_statwrite = false;
need_timer = true;
}
/*
* Setup the descriptor set for select(2)
*/
FD_ZERO(&rfds);
FD_SET(readPipe, &rfds);
/*
* Now wait for something to do.
*/
if (select(readPipe + 1, &rfds, NULL, NULL, NULL) < 0)
{
if (errno == EINTR)
continue;
ereport(ERROR,
(errcode_for_socket_access(),
errmsg("select() failed in statistics collector: %m")));
}
/*
* 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 */
bool pipeEOF = false;
while (nread < targetlen)
{
len = piperead(readPipe, ((char *) &msg) + nread,
targetlen - nread);
if (len < 0)
{
if (errno == EINTR)
continue;
ereport(ERROR,
(errcode_for_socket_access(),
errmsg("could not read from statistics collector pipe: %m")));
}
if (len == 0) /* EOF on the pipe! */
{
pipeEOF = true;
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.
*/
ereport(ERROR,
(errmsg("invalid statistics message length")));
}
}
}
/*
* EOF on the pipe implies that the buffer process exited. Fall
* out of outer loop.
*/
if (pipeEOF)
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;
case PGSTAT_MTYPE_AUTOVAC_START:
pgstat_recv_autovac((PgStat_MsgAutovacStart *) &msg, nread);
break;
case PGSTAT_MTYPE_VACUUM:
pgstat_recv_vacuum((PgStat_MsgVacuum *) &msg, nread);
break;
case PGSTAT_MTYPE_ANALYZE:
pgstat_recv_analyze((PgStat_MsgAnalyze *) &msg, nread);
break;
case PGSTAT_MTYPE_REWRITE:
need_statwrite = true;
/* Disable the timer - it will be restarted on next data update */
setitimer(ITIMER_REAL, &canceltimeout, NULL);
break;
default:
break;
}
/*
* Globally count messages.
*/
pgStatNumMessages++;
/*
* If this is the first message after we wrote the stats file the
* last time, enable the alarm interrupt to make it be written
* again later.
*/
if (need_timer)
{
if (setitimer(ITIMER_REAL, &timeout, NULL))
ereport(ERROR,
(errmsg("could not set statistics collector timer: %m")));
need_timer = false;
}
}
/*
* 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).
*/
if (!PostmasterIsAlive(false))
pgstat_write_statsfile();
}
/* SIGALRM signal handler for collector process */
static void
force_statwrite(SIGNAL_ARGS)
{
need_statwrite = true;
}
/* ----------
* 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;
struct timeval timeout;
int writePipe = pgStatPipe[1];
int maxfd;
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 */
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 (!pg_set_noblock(writePipe))
ereport(ERROR,
(errcode_for_socket_access(),
errmsg("could not set statistics collector pipe to nonblocking mode: %m")));
/*
* Allocate the message buffer
*/
msgbuffer = (char *) palloc(PGSTAT_RECVBUFFERSZ);
/*
* 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)
{
ereport(LOG,
(errmsg("statistics buffer is full")));
overflow = true;
}
}
/*
* If we have messages to write out, we add the pipe to the write
* descriptor set.
*/
if (msg_have > 0)
{
FD_SET(writePipe, &wfds);
if (writePipe > maxfd)
maxfd = writePipe;
}
/*
* Wait for some work to do; but not for more than 10 seconds. (This
* determines how quickly we will shut down after an ungraceful
* postmaster termination; so it needn't be very fast.)
*
* struct timeout is modified by select() on some operating systems,
* so re-fill it each time.
*/
timeout.tv_sec = 10;
timeout.tv_usec = 0;
if (select(maxfd + 1, &rfds, &wfds, NULL, &timeout) < 0)
{
if (errno == EINTR)
continue;
ereport(ERROR,
(errcode_for_socket_access(),
errmsg("select() failed in statistics buffer: %m")));
}
/*
* If there is a message on the socket, read it and check for
* validity.
*/
if (FD_ISSET(pgStatSock, &rfds))
{
len = recv(pgStatSock, (char *) &input_buffer,
sizeof(PgStat_Msg), 0);
if (len < 0)
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 (input_buffer.msg_hdr.m_size != len)
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 = pipewrite(writePipe, msgbuffer + msg_send, xfr);
if (len < 0)
{
if (errno == EINTR || errno == EAGAIN)
continue; /* not enough space in pipe */
ereport(ERROR,
(errcode_for_socket_access(),
errmsg("could not write to statistics collector pipe: %m")));
}
/* 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 postmaster has terminated, we die too. (This is no longer
* the normal exit path, however.)
*/
if (!PostmasterIsAlive(true))
exit(0);
}
}
/* SIGQUIT signal handler for buffer process */
static void
pgstat_exit(SIGNAL_ARGS)
{
/*
* For now, we just nail the doors shut and get out of town. It might be
* cleaner to allow any pending messages to be sent, but that creates a
* tradeoff against speed of exit.
*/
/*
* If running in bufferer, kill our collector as well. On some broken
* win32 systems, it does not shut down automatically because of issues
* with socket inheritance. XXX so why not fix the socket inheritance...
*/
#ifdef WIN32
if (pgStatCollectorPid > 0)
kill(pgStatCollectorPid, SIGQUIT);
#endif
exit(0);
}
/* SIGCHLD signal handler for buffer process */
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_StatBeEntry *beentry;
/*
* Check that the backend ID is valid
*/
if (msg->m_backendid < 1 || msg->m_backendid > MaxBackends)
{
ereport(LOG,
(errmsg("invalid server process ID %d", msg->m_backendid)));
return -1;
}
/*
* Get the slot for this backendid.
*/
beentry = &pgStatBeTable[msg->m_backendid - 1];
/*
* If the slot contains the PID of this backend, everything is fine and we
* have nothing to do. Note that all the slots are zero'd out when the
* collector is started. We assume that a slot is "empty" iff procpid ==
* 0.
*/
if (beentry->procpid > 0 && beentry->procpid == msg->m_procpid)
return 0;
/* Must be able to distinguish between empty and non-empty slots */
Assert(msg->m_procpid > 0);
/*
* Put this new backend into the slot (possibly overwriting an old entry,
* if we missed its BETERM or the BETERM hasn't arrived yet).
*/
beentry->procpid = msg->m_procpid;
beentry->start_timestamp = GetCurrentTimestamp();
beentry->activity_start_timestamp = 0;
beentry->activity[0] = '\0';
/*
* We can't initialize the rest of the data in this slot until we see the
* BESTART message. Therefore, we set the database and user to sentinel
* values, to indicate "undefined". There is no easy way to do this for
* the client address, so make sure to check that the database or user are
* defined before accessing the client address.
*/
beentry->userid = InvalidOid;
beentry->databaseid = InvalidOid;
return 0;
}
/*
* Lookup the hash table entry for the specified database. If no hash
* table entry exists, initialize it, if the create parameter is true.
* Else, return NULL.
*/
static PgStat_StatDBEntry *
pgstat_get_db_entry(Oid databaseid, bool create)
{
PgStat_StatDBEntry *result;
bool found;
HASHACTION action = (create ? HASH_ENTER : HASH_FIND);
/* Lookup or create the hash table entry for this database */
result = (PgStat_StatDBEntry *) hash_search(pgStatDBHash,
&databaseid,
action, &found);
if (!create && !found)
return NULL;
/* If not found, initialize the new one. */
if (!found)
{
HASHCTL hash_ctl;
result->tables = NULL;
result->n_xact_commit = 0;
result->n_xact_rollback = 0;
result->n_blocks_fetched = 0;
result->n_blocks_hit = 0;
result->last_autovac_time = 0;
memset(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(PgStat_StatTabEntry);
hash_ctl.hash = oid_hash;
result->tables = hash_create("Per-database table",
PGSTAT_TAB_HASH_SIZE,
&hash_ctl,
HASH_ELEM | HASH_FUNCTION);
}
return result;
}
/* ----------
* pgstat_sub_backend() -
*
* Remove a backend from the actual backends list.
* ----------
*/
static void
pgstat_sub_backend(int procpid)
{
int i;
/*
* Search in the known-backends table for the slot containing this PID.
*/
for (i = 0; i < MaxBackends; i++)
{
if (pgStatBeTable[i].procpid == procpid)
{
/*
* That's him. Mark the backend slot empty.
*/
pgStatBeTable[i].procpid = 0;
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;
FILE *fpout;
int i;
int32 format_id;
/*
* Open the statistics temp file to write out the current values.
*/
fpout = fopen(PGSTAT_STAT_TMPFILE, PG_BINARY_W);
if (fpout == NULL)
{
ereport(LOG,
(errcode_for_file_access(),
errmsg("could not open temporary statistics file \"%s\": %m",
PGSTAT_STAT_TMPFILE)));
return;
}
/*
* Write the file header --- currently just a format ID.
*/
format_id = PGSTAT_FILE_FORMAT_ID;
fwrite(&format_id, sizeof(format_id), 1, fpout);
/*
* Walk through the database table.
*/
hash_seq_init(&hstat, pgStatDBHash);
while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
{
/*
* Write out the DB entry including the number of live backends.
* We don't write the tables pointer since it's of no use to any
* other process.
*/
fputc('D', fpout);
fwrite(dbentry, offsetof(PgStat_StatDBEntry, tables), 1, fpout);
/*
* Walk through the database's access stats per table.
*/
hash_seq_init(&tstat, dbentry->tables);
while ((tabentry = (PgStat_StatTabEntry *) hash_seq_search(&tstat)) != NULL)
{
fputc('T', fpout);
fwrite(tabentry, sizeof(PgStat_StatTabEntry), 1, fpout);
}
/*
* Mark the end of this DB
*/
fputc('d', fpout);
}
/*
* 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++)
{
PgStat_StatBeEntry *beentry = &pgStatBeTable[i];
if (beentry->procpid > 0)
{
int len;
len = offsetof(PgStat_StatBeEntry, activity) +
strlen(beentry->activity) + 1;
fputc('B', fpout);
fwrite(&len, sizeof(len), 1, fpout);
fwrite(beentry, len, 1, fpout);
}
}
/*
* No more output to be done. Close the temp file and replace the old
* pgstat.stat with it. The ferror() check replaces testing for error
* after each individual fputc or fwrite above.
*/
fputc('E', fpout);
if (ferror(fpout))
{
ereport(LOG,
(errcode_for_file_access(),
errmsg("could not write temporary statistics file \"%s\": %m",
PGSTAT_STAT_TMPFILE)));
fclose(fpout);
unlink(PGSTAT_STAT_TMPFILE);
}
else if (fclose(fpout) < 0)
{
ereport(LOG,
(errcode_for_file_access(),
errmsg("could not close temporary statistics file \"%s\": %m",
PGSTAT_STAT_TMPFILE)));
unlink(PGSTAT_STAT_TMPFILE);
}
else if (rename(PGSTAT_STAT_TMPFILE, PGSTAT_STAT_FILENAME) < 0)
{
ereport(LOG,
(errcode_for_file_access(),
errmsg("could not rename temporary statistics file \"%s\" to \"%s\": %m",
PGSTAT_STAT_TMPFILE, PGSTAT_STAT_FILENAME)));
unlink(PGSTAT_STAT_TMPFILE);
}
}
/*
* qsort/bsearch comparison routine for PIDs
*
* We assume PIDs are nonnegative, so there's no overflow risk
*/
static int
comparePids(const void *v1, const void *v2)
{
return *((const int *) v1) - *((const int *) v2);
}
/* ----------
* pgstat_read_statsfile() -
*
* Reads in an existing statistics collector and initializes the
* databases' hash table (whose 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, bool rewrite)
{
PgStat_StatDBEntry *dbentry;
PgStat_StatDBEntry dbbuf;
PgStat_StatTabEntry *tabentry;
PgStat_StatTabEntry tabbuf;
PgStat_StatBeEntry *beentry;
HASHCTL hash_ctl;
HTAB *tabhash = NULL;
FILE *fpin;
int32 format_id;
int len;
int maxbackends = 0;
int havebackends = 0;
bool found;
int *live_pids;
MemoryContext use_mcxt;
int mcxt_flags;
if (rewrite)
{
/*
* To force a rewrite of the stats file from the collector, send
* a REWRITE message to the stats collector. Then wait for the file
* to change. On Unix, we wait for the inode to change (as the file
* is renamed into place from a different file). Win32 has no concept
* of inodes, so we wait for the date on the file to change instead.
* We can do this on win32 because we have high-res timing on the
* file dates, but we can't on unix, because it has 1sec resolution
* on the fields in struct stat.
*/
int i;
#ifndef WIN32
struct stat st1, st2;
if (stat(PGSTAT_STAT_FILENAME, &st1))
{
/* Assume no file there yet */
st1.st_ino = 0;
}
st2.st_ino = 0;
#else
WIN32_FILE_ATTRIBUTE_DATA fd1, fd2;
if (!GetFileAttributesEx(PGSTAT_STAT_FILENAME, GetFileExInfoStandard, &fd1))
{
fd1.ftLastWriteTime.dwLowDateTime = 0;
fd1.ftLastWriteTime.dwHighDateTime = 0;
}
fd2.ftLastWriteTime.dwLowDateTime = 0;
fd2.ftLastWriteTime.dwHighDateTime = 0;
#endif
/* Send rewrite message */
pgstat_send_rewrite();
/* Now wait for the file to change */
for (i=0; i < 50; i++)
{
#ifndef WIN32
if (!stat(PGSTAT_STAT_FILENAME, &st2))
{
if (st2.st_ino != st1.st_ino)
break;
}
#else
if (GetFileAttributesEx(PGSTAT_STAT_FILENAME, GetFileExInfoStandard, &fd2))
{
if (fd1.ftLastWriteTime.dwLowDateTime != fd2.ftLastWriteTime.dwLowDateTime ||
fd1.ftLastWriteTime.dwHighDateTime != fd2.ftLastWriteTime.dwHighDateTime)
break;
}
#endif
pg_usleep(50000);
}
if (i >= 50)
ereport(WARNING,
(errmsg("pgstat update timeout")));
/* Fallthrough and read the old file anyway - old data better than no data */
}
/*
* If running in the collector or the autovacuum process, 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!
*
* Also, if running in a regular backend, we check backend entries against
* the PGPROC array so that we can detect stale entries. This lets us
* discard entries whose BETERM message got lost for some reason.
*/
if (pgStatRunningInCollector || IsAutoVacuumProcess())
{
use_mcxt = NULL;
mcxt_flags = 0;
live_pids = NULL;
}
else
{
use_mcxt = TopTransactionContext;
mcxt_flags = HASH_CONTEXT;
live_pids = GetAllBackendPids();
/* Sort the PID array so we can use bsearch */
if (live_pids[0] > 1)
qsort((void *) &live_pids[1], live_pids[0], sizeof(int),
comparePids);
}
/*
* Create the DB hashtable
*/
memset(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(PgStat_StatDBEntry);
hash_ctl.hash = oid_hash;
hash_ctl.hcxt = use_mcxt;
*dbhash = hash_create("Databases hash", PGSTAT_DB_HASH_SIZE, &hash_ctl,
HASH_ELEM | HASH_FUNCTION | mcxt_flags);
/*
* 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 = AllocateFile(PGSTAT_STAT_FILENAME, PG_BINARY_R)) == NULL)
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 pgstat.stat file")));
goto done;
}
/*
* We found an existing collector stats file. Read it and put all the
* hashtable entries into place.
*/
for (;;)
{
switch (fgetc(fpin))
{
/*
* 'D' A PgStat_StatDBEntry struct describing a database
* follows. Subsequently, zero to many 'T' entries will follow
* until a 'd' is encountered.
*/
case 'D':
if (fread(&dbbuf, 1, offsetof(PgStat_StatDBEntry, tables),
fpin) != offsetof(PgStat_StatDBEntry, tables))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
/*
* Add to the DB hash
*/
dbentry = (PgStat_StatDBEntry *) hash_search(*dbhash,
(void *) &dbbuf.databaseid,
HASH_ENTER,
&found);
if (found)
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
memcpy(dbentry, &dbbuf, sizeof(PgStat_StatDBEntry));
dbentry->tables = NULL;
dbentry->n_backends = 0;
/*
* Don't collect tables if not the requested DB (or the
* shared-table info)
*/
if (onlydb != InvalidOid)
{
if (dbbuf.databaseid != onlydb &&
dbbuf.databaseid != InvalidOid)
break;
}
memset(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(PgStat_StatTabEntry);
hash_ctl.hash = oid_hash;
hash_ctl.hcxt = use_mcxt;
dbentry->tables = hash_create("Per-database table",
PGSTAT_TAB_HASH_SIZE,
&hash_ctl,
HASH_ELEM | HASH_FUNCTION | mcxt_flags);
/*
* Arrange that following 'T's add entries to this database's
* tables hash table.
*/
tabhash = dbentry->tables;
break;
/*
* 'd' End of this database.
*/
case 'd':
tabhash = NULL;
break;
/*
* 'T' A PgStat_StatTabEntry follows.
*/
case 'T':
if (fread(&tabbuf, 1, sizeof(PgStat_StatTabEntry),
fpin) != sizeof(PgStat_StatTabEntry))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
/*
* Skip if table belongs to a not requested database.
*/
if (tabhash == NULL)
break;
tabentry = (PgStat_StatTabEntry *) hash_search(tabhash,
(void *) &tabbuf.tableid,
HASH_ENTER, &found);
if (found)
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
memcpy(tabentry, &tabbuf, sizeof(tabbuf));
break;
/*
* 'M' The maximum number of backends to expect follows.
*/
case 'M':
if (betab == NULL || numbackends == NULL)
goto done;
if (fread(&maxbackends, 1, sizeof(maxbackends), fpin) !=
sizeof(maxbackends))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
if (maxbackends == 0)
goto done;
/*
* Allocate space (in TopTransactionContext too) for the
* backend table.
*/
if (use_mcxt == NULL)
*betab = (PgStat_StatBeEntry *)
palloc(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 || *betab == NULL)
goto done;
if (havebackends >= maxbackends)
goto done;
/* Read and validate the entry length */
if (fread(&len, 1, sizeof(len), fpin) != sizeof(len))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
if (len <= offsetof(PgStat_StatBeEntry, activity) ||
len > sizeof(PgStat_StatBeEntry))
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
/*
* Read it directly into the table.
*/
beentry = &(*betab)[havebackends];
if (fread(beentry, 1, len, fpin) != len)
{
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
/*
* If possible, check PID to verify still running
*/
if (live_pids &&
(live_pids[0] == 0 ||
bsearch((void *) &beentry->procpid,
(void *) &live_pids[1],
live_pids[0],
sizeof(int),
comparePids) == NULL))
{
/*
* Note: we could send a BETERM message to tell the
* collector to drop the entry, but I'm a bit worried
* about race conditions. For now, just silently ignore
* dead entries; they'll get recycled eventually anyway.
*/
/* Don't accept the entry */
memset(beentry, 0, sizeof(PgStat_StatBeEntry));
break;
}
/*
* Count backends per database here.
*/
dbentry = (PgStat_StatDBEntry *)
hash_search(*dbhash,
&(beentry->databaseid),
HASH_FIND,
NULL);
if (dbentry)
dbentry->n_backends++;
havebackends++;
*numbackends = havebackends;
break;
/*
* 'E' The EOF marker of a complete stats file.
*/
case 'E':
goto done;
default:
ereport(pgStatRunningInCollector ? LOG : WARNING,
(errmsg("corrupted pgstat.stat file")));
goto done;
}
}
done:
FreeFile(fpin);
}
/*
* If not done for this transaction, read the statistics collector
* stats file into some hash tables.
*
* Because we store the hash tables in TopTransactionContext, the result
* is good for the entire current main transaction.
*
* Inside the autovacuum process, the statfile is assumed to be valid
* "forever", that is one iteration, within one database. This means
* we only consider the statistics as they were when the autovacuum
* iteration started.
*/
static void
backend_read_statsfile(void)
{
if (IsAutoVacuumProcess())
{
/* already read it? */
if (pgStatDBHash)
return;
Assert(!pgStatRunningInCollector);
pgstat_read_statsfile(&pgStatDBHash, InvalidOid,
&pgStatBeTable, &pgStatNumBackends, true);
}
else
{
TransactionId topXid = GetTopTransactionId();
if (!TransactionIdEquals(pgStatDBHashXact, topXid))
{
Assert(!pgStatRunningInCollector);
pgstat_read_statsfile(&pgStatDBHash, MyDatabaseId,
&pgStatBeTable, &pgStatNumBackends, true);
pgStatDBHashXact = topXid;
}
}
}
/* ----------
* pgstat_recv_bestart() -
*
* Process a backend startup message.
* ----------
*/
static void
pgstat_recv_bestart(PgStat_MsgBestart *msg, int len)
{
PgStat_StatBeEntry *entry;
/*
* If the backend is known dead, we ignore the message -- we don't want to
* update the backend entry's state since this BESTART message refers to
* an old, dead backend
*/
if (pgstat_add_backend(&msg->m_hdr) != 0)
return;
entry = &(pgStatBeTable[msg->m_hdr.m_backendid - 1]);
entry->userid = msg->m_userid;
memcpy(&entry->clientaddr, &msg->m_clientaddr, sizeof(entry->clientaddr));
entry->databaseid = msg->m_databaseid;
}
/* ----------
* 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_autovac() -
*
* Process an autovacuum signalling message.
* ----------
*/
static void
pgstat_recv_autovac(PgStat_MsgAutovacStart *msg, int len)
{
PgStat_StatDBEntry *dbentry;
/*
* Lookup the database in the hashtable. Don't create the entry if it
* doesn't exist, because autovacuum may be processing a template
* database. If this isn't the case, the database is most likely to have
* an entry already. (If it doesn't, not much harm is done anyway --
* it'll get created as soon as somebody actually uses the database.)
*/
dbentry = pgstat_get_db_entry(msg->m_databaseid, false);
if (dbentry == NULL)
return;
/*
* Store the last autovacuum time in the database entry.
*/
dbentry->last_autovac_time = msg->m_start_time;
}
/* ----------
* pgstat_recv_vacuum() -
*
* Process a VACUUM message.
* ----------
*/
static void
pgstat_recv_vacuum(PgStat_MsgVacuum *msg, int len)
{
PgStat_StatDBEntry *dbentry;
PgStat_StatTabEntry *tabentry;
/*
* Don't create either the database or table entry if it doesn't already
* exist. This avoids bloating the stats with entries for stuff that is
* only touched by vacuum and not by live operations.
*/
dbentry = pgstat_get_db_entry(msg->m_databaseid, false);
if (dbentry == NULL)
return;
tabentry = hash_search(dbentry->tables, &(msg->m_tableoid),
HASH_FIND, NULL);
if (tabentry == NULL)
return;
if (msg->m_autovacuum)
tabentry->autovac_vacuum_timestamp = msg->m_vacuumtime;
else
tabentry->vacuum_timestamp = msg->m_vacuumtime;
tabentry->n_live_tuples = msg->m_tuples;
tabentry->n_dead_tuples = 0;
if (msg->m_analyze)
{
tabentry->last_anl_tuples = msg->m_tuples;
if (msg->m_autovacuum)
tabentry->autovac_analyze_timestamp = msg->m_vacuumtime;
else
tabentry->analyze_timestamp = msg->m_vacuumtime;
}
}
/* ----------
* pgstat_recv_analyze() -
*
* Process an ANALYZE message.
* ----------
*/
static void
pgstat_recv_analyze(PgStat_MsgAnalyze *msg, int len)
{
PgStat_StatDBEntry *dbentry;
PgStat_StatTabEntry *tabentry;
/*
* Don't create either the database or table entry if it doesn't already
* exist. This avoids bloating the stats with entries for stuff that is
* only touched by analyze and not by live operations.
*/
dbentry = pgstat_get_db_entry(msg->m_databaseid, false);
if (dbentry == NULL)
return;
tabentry = hash_search(dbentry->tables, &(msg->m_tableoid),
HASH_FIND, NULL);
if (tabentry == NULL)
return;
if (msg->m_autovacuum)
tabentry->autovac_analyze_timestamp = msg->m_analyzetime;
else
tabentry->analyze_timestamp = msg->m_analyzetime;
tabentry->n_live_tuples = msg->m_live_tuples;
tabentry->n_dead_tuples = msg->m_dead_tuples;
tabentry->last_anl_tuples = msg->m_live_tuples + msg->m_dead_tuples;
}
/* ----------
* pgstat_recv_activity() -
*
* Remember what the backend is doing.
* ----------
*/
static void
pgstat_recv_activity(PgStat_MsgActivity *msg, int len)
{
PgStat_StatBeEntry *entry;
/*
* Here we check explicitly for 0 return, since we don't want to mangle
* the activity of an active backend by a delayed packet from a dead one.
*/
if (pgstat_add_backend(&msg->m_hdr) != 0)
return;
entry = &(pgStatBeTable[msg->m_hdr.m_backendid - 1]);
StrNCpy(entry->activity, msg->m_cmd_str, PGSTAT_ACTIVITY_SIZE);
entry->activity_start_timestamp = GetCurrentTimestamp();
}
/* ----------
* 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;
dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
/*
* Update database-wide stats.
*/
dbentry->n_xact_commit += (PgStat_Counter) (msg->m_xact_commit);
dbentry->n_xact_rollback += (PgStat_Counter) (msg->m_xact_rollback);
/*
* Process all table entries in the message.
*/
for (i = 0; i < msg->m_nentries; i++)
{
tabentry = (PgStat_StatTabEntry *) hash_search(dbentry->tables,
(void *) &(tabmsg[i].t_id),
HASH_ENTER, &found);
if (!found)
{
/*
* If it's a new table entry, initialize counters to the values we
* just got.
*/
tabentry->numscans = tabmsg[i].t_numscans;
tabentry->tuples_returned = tabmsg[i].t_tuples_returned;
tabentry->tuples_fetched = tabmsg[i].t_tuples_fetched;
tabentry->tuples_inserted = tabmsg[i].t_tuples_inserted;
tabentry->tuples_updated = tabmsg[i].t_tuples_updated;
tabentry->tuples_deleted = tabmsg[i].t_tuples_deleted;
tabentry->n_live_tuples = tabmsg[i].t_tuples_inserted;
tabentry->n_dead_tuples = tabmsg[i].t_tuples_updated +
tabmsg[i].t_tuples_deleted;
tabentry->last_anl_tuples = 0;
tabentry->vacuum_timestamp = 0;
tabentry->autovac_vacuum_timestamp = 0;
tabentry->analyze_timestamp = 0;
tabentry->autovac_analyze_timestamp = 0;
tabentry->blocks_fetched = tabmsg[i].t_blocks_fetched;
tabentry->blocks_hit = tabmsg[i].t_blocks_hit;
}
else
{
/*
* Otherwise add the values to the existing entry.
*/
tabentry->numscans += tabmsg[i].t_numscans;
tabentry->tuples_returned += tabmsg[i].t_tuples_returned;
tabentry->tuples_fetched += tabmsg[i].t_tuples_fetched;
tabentry->tuples_inserted += tabmsg[i].t_tuples_inserted;
tabentry->tuples_updated += tabmsg[i].t_tuples_updated;
tabentry->tuples_deleted += tabmsg[i].t_tuples_deleted;
tabentry->n_live_tuples += tabmsg[i].t_tuples_inserted;
tabentry->n_dead_tuples += tabmsg[i].t_tuples_updated +
tabmsg[i].t_tuples_deleted;
tabentry->blocks_fetched += tabmsg[i].t_blocks_fetched;
tabentry->blocks_hit += tabmsg[i].t_blocks_hit;
}
/*
* And add the block IO to the database entry.
*/
dbentry->n_blocks_fetched += tabmsg[i].t_blocks_fetched;
dbentry->n_blocks_hit += tabmsg[i].t_blocks_hit;
}
}
/* ----------
* pgstat_recv_tabpurge() -
*
* Arrange for dead table removal.
* ----------
*/
static void
pgstat_recv_tabpurge(PgStat_MsgTabpurge *msg, int len)
{
PgStat_StatDBEntry *dbentry;
int i;
/*
* Make sure the backend is counted for.
*/
if (pgstat_add_backend(&msg->m_hdr) < 0)
return;
dbentry = pgstat_get_db_entry(msg->m_databaseid, false);
/*
* No need to purge if we don't even know the database.
*/
if (!dbentry || !dbentry->tables)
return;
/*
* Process all table entries in the message.
*/
for (i = 0; i < msg->m_nentries; i++)
{
/* Remove from hashtable if present; we don't care if it's not. */
(void) hash_search(dbentry->tables,
(void *) &(msg->m_tableid[i]),
HASH_REMOVE, NULL);
}
}
/* ----------
* pgstat_recv_dropdb() -
*
* Arrange for dead database removal
* ----------
*/
static void
pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
{
PgStat_StatDBEntry *dbentry;
/*
* Make sure the backend is counted for.
*/
if (pgstat_add_backend(&msg->m_hdr) < 0)
return;
/*
* Lookup the database in the hashtable.
*/
dbentry = pgstat_get_db_entry(msg->m_databaseid, false);
/*
* If found, remove it.
*/
if (dbentry)
{
if (dbentry->tables != NULL)
hash_destroy(dbentry->tables);
if (hash_search(pgStatDBHash,
(void *) &(dbentry->databaseid),
HASH_REMOVE, NULL) == NULL)
ereport(ERROR,
(errmsg("database hash table corrupted "
"during cleanup --- abort")));
}
}
/* ----------
* pgstat_recv_resetcounter() -
*
* Reset the statistics for the specified database.
* ----------
*/
static void
pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
{
HASHCTL hash_ctl;
PgStat_StatDBEntry *dbentry;
/*
* Make sure the backend is counted for.
*/
if (pgstat_add_backend(&msg->m_hdr) < 0)
return;
/*
* Lookup the database in the hashtable. Nothing to do if not there.
*/
dbentry = pgstat_get_db_entry(msg->m_databaseid, false);
if (!dbentry)
return;
/*
* We simply throw away all the database's table entries by recreating a
* new hash table for them.
*/
if (dbentry->tables != NULL)
hash_destroy(dbentry->tables);
dbentry->tables = NULL;
dbentry->n_xact_commit = 0;
dbentry->n_xact_rollback = 0;
dbentry->n_blocks_fetched = 0;
dbentry->n_blocks_hit = 0;
memset(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = sizeof(Oid);
hash_ctl.entrysize = sizeof(PgStat_StatTabEntry);
hash_ctl.hash = oid_hash;
dbentry->tables = hash_create("Per-database table",
PGSTAT_TAB_HASH_SIZE,
&hash_ctl,
HASH_ELEM | HASH_FUNCTION);
}
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