Header And Logo
|
#include "postgres.h"#include <signal.h>#include <sys/types.h>#include <sys/time.h>#include <unistd.h>#include "access/heapam.h"#include "access/htup_details.h"#include "access/multixact.h"#include "access/reloptions.h"#include "access/transam.h"#include "access/xact.h"#include "catalog/dependency.h"#include "catalog/namespace.h"#include "catalog/pg_database.h"#include "commands/dbcommands.h"#include "commands/vacuum.h"#include "lib/ilist.h"#include "libpq/pqsignal.h"#include "miscadmin.h"#include "pgstat.h"#include "postmaster/autovacuum.h"#include "postmaster/fork_process.h"#include "postmaster/postmaster.h"#include "storage/bufmgr.h"#include "storage/ipc.h"#include "storage/latch.h"#include "storage/pmsignal.h"#include "storage/proc.h"#include "storage/procsignal.h"#include "storage/sinvaladt.h"#include "tcop/tcopprot.h"#include "utils/fmgroids.h"#include "utils/lsyscache.h"#include "utils/memutils.h"#include "utils/ps_status.h"#include "utils/rel.h"#include "utils/snapmgr.h"#include "utils/syscache.h"#include "utils/timeout.h"#include "utils/timestamp.h"#include "utils/tqual.h"
Go to the source code of this file.
| #define MAX_AUTOVAC_ACTIV_LEN (NAMEDATALEN * 2 + 56) |
Referenced by autovac_report_activity().
| #define MIN_AUTOVAC_SLEEPTIME 100.0 |
Definition at line 129 of file autovacuum.c.
Referenced by launcher_determine_sleep(), and rebuild_database_list().
| #define STATS_READ_DELAY 1000 |
Definition at line 126 of file autovacuum.c.
Referenced by autovac_refresh_stats().
| typedef struct autovac_table autovac_table |
| typedef struct av_relation av_relation |
| typedef struct WorkerInfoData* WorkerInfo |
Definition at line 225 of file autovacuum.c.
| typedef struct WorkerInfoData WorkerInfoData |
| enum AutoVacuumSignal |
Definition at line 232 of file autovacuum.c.
{
AutoVacForkFailed, /* failed trying to start a worker */
AutoVacRebalance, /* rebalance the cost limits */
AutoVacNumSignals /* must be last */
} AutoVacuumSignal;
| static void autovac_balance_cost | ( | void | ) | [static] |
Definition at line 1753 of file autovacuum.c.
References autovacuum_vac_cost_delay, autovacuum_vac_cost_limit, AutoVacuumShmemStruct::av_runningWorkers, dlist_iter::cur, DEBUG2, dlist_container, dlist_foreach, elog, Max, Min, NULL, PGPROC::pid, VacuumCostDelay, VacuumCostLimit, WorkerInfoData::wi_cost_delay, WorkerInfoData::wi_cost_limit, WorkerInfoData::wi_cost_limit_base, WorkerInfoData::wi_dboid, WorkerInfoData::wi_proc, and WorkerInfoData::wi_tableoid.
Referenced by AutoVacLauncherMain(), and do_autovacuum().
{
/*
* The idea here is that we ration out I/O equally. The amount of I/O
* that a worker can consume is determined by cost_limit/cost_delay, so we
* try to equalize those ratios rather than the raw limit settings.
*
* note: in cost_limit, zero also means use value from elsewhere, because
* zero is not a valid value.
*/
int vac_cost_limit = (autovacuum_vac_cost_limit > 0 ?
autovacuum_vac_cost_limit : VacuumCostLimit);
int vac_cost_delay = (autovacuum_vac_cost_delay >= 0 ?
autovacuum_vac_cost_delay : VacuumCostDelay);
double cost_total;
double cost_avail;
dlist_iter iter;
/* not set? nothing to do */
if (vac_cost_limit <= 0 || vac_cost_delay <= 0)
return;
/* caculate the total base cost limit of active workers */
cost_total = 0.0;
dlist_foreach(iter, &AutoVacuumShmem->av_runningWorkers)
{
WorkerInfo worker = dlist_container(WorkerInfoData, wi_links, iter.cur);
if (worker->wi_proc != NULL &&
worker->wi_cost_limit_base > 0 && worker->wi_cost_delay > 0)
cost_total +=
(double) worker->wi_cost_limit_base / worker->wi_cost_delay;
}
/* there are no cost limits -- nothing to do */
if (cost_total <= 0)
return;
/*
* Adjust cost limit of each active worker to balance the total of cost
* limit to autovacuum_vacuum_cost_limit.
*/
cost_avail = (double) vac_cost_limit / vac_cost_delay;
dlist_foreach(iter, &AutoVacuumShmem->av_runningWorkers)
{
WorkerInfo worker = dlist_container(WorkerInfoData, wi_links, iter.cur);
if (worker->wi_proc != NULL &&
worker->wi_cost_limit_base > 0 && worker->wi_cost_delay > 0)
{
int limit = (int)
(cost_avail * worker->wi_cost_limit_base / cost_total);
/*
* We put a lower bound of 1 on the cost_limit, to avoid division-
* by-zero in the vacuum code. Also, in case of roundoff trouble
* in these calculations, let's be sure we don't ever set
* cost_limit to more than the base value.
*/
worker->wi_cost_limit = Max(Min(limit,
worker->wi_cost_limit_base),
1);
elog(DEBUG2, "autovac_balance_cost(pid=%u db=%u, rel=%u, cost_limit=%d, cost_limit_base=%d, cost_delay=%d)",
worker->wi_proc->pid, worker->wi_dboid, worker->wi_tableoid,
worker->wi_cost_limit, worker->wi_cost_limit_base,
worker->wi_cost_delay);
}
}
}
| void autovac_init | ( | void | ) |
Definition at line 2831 of file autovacuum.c.
References autovacuum_start_daemon, ereport, errhint(), errmsg(), pgstat_track_counts, and WARNING.
Referenced by PostmasterMain().
{
if (autovacuum_start_daemon && !pgstat_track_counts)
ereport(WARNING,
(errmsg("autovacuum not started because of misconfiguration"),
errhint("Enable the \"track_counts\" option.")));
}
| static void autovac_refresh_stats | ( | void | ) | [static] |
Definition at line 2927 of file autovacuum.c.
References GetCurrentTimestamp(), IsAutoVacuumLauncherProcess(), pgstat_clear_snapshot(), STATS_READ_DELAY, and TimestampDifferenceExceeds().
Referenced by do_start_worker(), rebuild_database_list(), and table_recheck_autovac().
{
if (IsAutoVacuumLauncherProcess())
{
static TimestampTz last_read = 0;
TimestampTz current_time;
current_time = GetCurrentTimestamp();
if (!TimestampDifferenceExceeds(last_read, current_time,
STATS_READ_DELAY))
return;
last_read = current_time;
}
pgstat_clear_snapshot();
}
| static void autovac_report_activity | ( | autovac_table * | tab | ) | [static] |
Definition at line 2781 of file autovacuum.c.
References autovac_table::at_doanalyze, autovac_table::at_dovacuum, autovac_table::at_nspname, autovac_table::at_relname, autovac_table::at_wraparound, MAX_AUTOVAC_ACTIV_LEN, pgstat_report_activity(), SetCurrentStatementStartTimestamp(), snprintf(), and STATE_RUNNING.
Referenced by autovacuum_do_vac_analyze().
{
#define MAX_AUTOVAC_ACTIV_LEN (NAMEDATALEN * 2 + 56)
char activity[MAX_AUTOVAC_ACTIV_LEN];
int len;
/* Report the command and possible options */
if (tab->at_dovacuum)
snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
"autovacuum: VACUUM%s",
tab->at_doanalyze ? " ANALYZE" : "");
else
snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
"autovacuum: ANALYZE");
/*
* Report the qualified name of the relation.
*/
len = strlen(activity);
snprintf(activity + len, MAX_AUTOVAC_ACTIV_LEN - len,
" %s.%s%s", tab->at_nspname, tab->at_relname,
tab->at_wraparound ? " (to prevent wraparound)" : "");
/* Set statement_timestamp() to current time for pg_stat_activity */
SetCurrentStatementStartTimestamp();
pgstat_report_activity(STATE_RUNNING, activity);
}
| NON_EXEC_STATIC void AutoVacLauncherMain | ( | int | argc, | |
| char * | argv[] | |||
| ) |
Definition at line 399 of file autovacuum.c.
References AbortCurrentTransaction(), avl_dbase::adl_next_worker, ALLOCSET_DEFAULT_INITSIZE, ALLOCSET_DEFAULT_MAXSIZE, ALLOCSET_DEFAULT_MINSIZE, AllocSetContextCreate(), am_autovacuum_launcher, autovac_balance_cost(), AutoVacForkFailed, AutoVacRebalance, autovacuum_naptime, AutoVacuumingActive(), AutovacuumLock, AutoVacuumShmemStruct::av_freeWorkers, AutoVacuumShmemStruct::av_launcherpid, AutoVacuumShmemStruct::av_signal, AutoVacuumShmemStruct::av_startingWorker, avl_sighup_handler(), avl_sigterm_handler(), avl_sigusr2_handler(), BaseInit(), disable_all_timeouts(), DisableCatchupInterrupt(), dlist_init(), dlist_is_empty(), dlist_push_head(), dlist_tail_element, do_start_worker(), elog, EmitErrorReport(), EnableCatchupInterrupt(), ereport, errmsg(), error_context_stack, FATAL, FloatExceptionHandler(), FlushErrorState(), GetCurrentTimestamp(), got_SIGHUP, got_SIGTERM, got_SIGUSR2, HOLD_INTERRUPTS, init_ps_display(), InitializeTimeouts(), InitPostgres(), InitProcess(), InitProcessing, InvalidOid, IsUnderPostmaster, launch_worker(), launcher_determine_sleep(), LOG, LW_EXCLUSIVE, LW_SHARED, LWLockAcquire(), LWLockRelease(), MemoryContextResetAndDeleteChildren(), MemoryContextSwitchTo(), Min, MyProc, MyProcPid, MyStartTime, NormalProcessing, NULL, PG_exception_stack, PG_SETMASK, pg_usleep(), PGC_S_OVERRIDE, PGC_SIGHUP, PGC_SUSET, pgstat_clear_snapshot(), PMSIGNAL_START_AUTOVAC_WORKER, PostAuthDelay, pqsignal(), proc_exit(), ProcessConfigFile(), PGPROC::procLatch, procsignal_sigusr1_handler(), QueryCancelPending, quickdie(), rebuild_database_list(), ResetLatch(), RESUME_INTERRUPTS, SendPostmasterSignal(), SetConfigOption(), SetProcessingMode, SIG_DFL, SIG_IGN, SIGCHLD, SIGHUP, sigjmp_buf, SIGPIPE, SIGQUIT, sigsetjmp, SIGUSR1, SIGUSR2, StatementCancelHandler(), TimestampDifferenceExceeds(), TopMemoryContext, UnBlockSig, WaitLatch(), waittime, WARNING, WorkerInfoData::wi_dboid, WorkerInfoData::wi_launchtime, WorkerInfoData::wi_links, WorkerInfoData::wi_proc, WorkerInfoData::wi_tableoid, WL_LATCH_SET, WL_POSTMASTER_DEATH, and WL_TIMEOUT.
Referenced by StartAutoVacLauncher().
{
sigjmp_buf local_sigjmp_buf;
/* we are a postmaster subprocess now */
IsUnderPostmaster = true;
am_autovacuum_launcher = true;
/* reset MyProcPid */
MyProcPid = getpid();
/* record Start Time for logging */
MyStartTime = time(NULL);
/* Identify myself via ps */
init_ps_display("autovacuum launcher process", "", "", "");
ereport(LOG,
(errmsg("autovacuum launcher started")));
if (PostAuthDelay)
pg_usleep(PostAuthDelay * 1000000L);
SetProcessingMode(InitProcessing);
/*
* If possible, make this process a group leader, so that the postmaster
* can signal any child processes too. (autovacuum probably never has any
* child processes, but for consistency we make all postmaster child
* processes do this.)
*/
#ifdef HAVE_SETSID
if (setsid() < 0)
elog(FATAL, "setsid() failed: %m");
#endif
/*
* Set up signal handlers. We operate on databases much like a regular
* backend, so we use the same signal handling. See equivalent code in
* tcop/postgres.c.
*/
pqsignal(SIGHUP, avl_sighup_handler);
pqsignal(SIGINT, StatementCancelHandler);
pqsignal(SIGTERM, avl_sigterm_handler);
pqsignal(SIGQUIT, quickdie);
InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, avl_sigusr2_handler);
pqsignal(SIGFPE, FloatExceptionHandler);
pqsignal(SIGCHLD, SIG_DFL);
/* Early initialization */
BaseInit();
/*
* Create a per-backend PGPROC struct in shared memory, except in the
* EXEC_BACKEND case where this was done in SubPostmasterMain. We must do
* this before we can use LWLocks (and in the EXEC_BACKEND case we already
* had to do some stuff with LWLocks).
*/
#ifndef EXEC_BACKEND
InitProcess();
#endif
InitPostgres(NULL, InvalidOid, NULL, NULL);
SetProcessingMode(NormalProcessing);
/*
* Create a memory context that we will do all our work in. We do this so
* that we can reset the context during error recovery and thereby avoid
* possible memory leaks.
*/
AutovacMemCxt = AllocSetContextCreate(TopMemoryContext,
"Autovacuum Launcher",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
MemoryContextSwitchTo(AutovacMemCxt);
/*
* If an exception is encountered, processing resumes here.
*
* This code is a stripped down version of PostgresMain error recovery.
*/
if (sigsetjmp(local_sigjmp_buf, 1) != 0)
{
/* since not using PG_TRY, must reset error stack by hand */
error_context_stack = NULL;
/* Prevents interrupts while cleaning up */
HOLD_INTERRUPTS();
/* Forget any pending QueryCancel or timeout request */
QueryCancelPending = false;
disable_all_timeouts(false);
QueryCancelPending = false; /* again in case timeout occurred */
/* Report the error to the server log */
EmitErrorReport();
/* Abort the current transaction in order to recover */
AbortCurrentTransaction();
/*
* Now return to normal top-level context and clear ErrorContext for
* next time.
*/
MemoryContextSwitchTo(AutovacMemCxt);
FlushErrorState();
/* Flush any leaked data in the top-level context */
MemoryContextResetAndDeleteChildren(AutovacMemCxt);
/* don't leave dangling pointers to freed memory */
DatabaseListCxt = NULL;
dlist_init(&DatabaseList);
/*
* Make sure pgstat also considers our stat data as gone. Note: we
* mustn't use autovac_refresh_stats here.
*/
pgstat_clear_snapshot();
/* Now we can allow interrupts again */
RESUME_INTERRUPTS();
/*
* Sleep at least 1 second after any error. We don't want to be
* filling the error logs as fast as we can.
*/
pg_usleep(1000000L);
}
/* We can now handle ereport(ERROR) */
PG_exception_stack = &local_sigjmp_buf;
/* must unblock signals before calling rebuild_database_list */
PG_SETMASK(&UnBlockSig);
/*
* Force zero_damaged_pages OFF in the autovac process, even if it is set
* in postgresql.conf. We don't really want such a dangerous option being
* applied non-interactively.
*/
SetConfigOption("zero_damaged_pages", "false", PGC_SUSET, PGC_S_OVERRIDE);
/*
* Force statement_timeout and lock_timeout to zero to avoid letting these
* settings prevent regular maintenance from being executed.
*/
SetConfigOption("statement_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
SetConfigOption("lock_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
/*
* Force default_transaction_isolation to READ COMMITTED. We don't want
* to pay the overhead of serializable mode, nor add any risk of causing
* deadlocks or delaying other transactions.
*/
SetConfigOption("default_transaction_isolation", "read committed",
PGC_SUSET, PGC_S_OVERRIDE);
/* in emergency mode, just start a worker and go away */
if (!AutoVacuumingActive())
{
do_start_worker();
proc_exit(0); /* done */
}
AutoVacuumShmem->av_launcherpid = MyProcPid;
/*
* Create the initial database list. The invariant we want this list to
* keep is that it's ordered by decreasing next_time. As soon as an entry
* is updated to a higher time, it will be moved to the front (which is
* correct because the only operation is to add autovacuum_naptime to the
* entry, and time always increases).
*/
rebuild_database_list(InvalidOid);
for (;;)
{
struct timeval nap;
TimestampTz current_time = 0;
bool can_launch;
int rc;
/*
* This loop is a bit different from the normal use of WaitLatch,
* because we'd like to sleep before the first launch of a child
* process. So it's WaitLatch, then ResetLatch, then check for
* wakening conditions.
*/
launcher_determine_sleep(!dlist_is_empty(&AutoVacuumShmem->av_freeWorkers),
false, &nap);
/* Allow sinval catchup interrupts while sleeping */
EnableCatchupInterrupt();
/*
* Wait until naptime expires or we get some type of signal (all the
* signal handlers will wake us by calling SetLatch).
*/
rc = WaitLatch(&MyProc->procLatch,
WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH,
(nap.tv_sec * 1000L) + (nap.tv_usec / 1000L));
ResetLatch(&MyProc->procLatch);
DisableCatchupInterrupt();
/*
* Emergency bailout if postmaster has died. This is to avoid the
* necessity for manual cleanup of all postmaster children.
*/
if (rc & WL_POSTMASTER_DEATH)
proc_exit(1);
/* the normal shutdown case */
if (got_SIGTERM)
break;
if (got_SIGHUP)
{
got_SIGHUP = false;
ProcessConfigFile(PGC_SIGHUP);
/* shutdown requested in config file? */
if (!AutoVacuumingActive())
break;
/* rebalance in case the default cost parameters changed */
LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
autovac_balance_cost();
LWLockRelease(AutovacuumLock);
/* rebuild the list in case the naptime changed */
rebuild_database_list(InvalidOid);
}
/*
* a worker finished, or postmaster signalled failure to start a
* worker
*/
if (got_SIGUSR2)
{
got_SIGUSR2 = false;
/* rebalance cost limits, if needed */
if (AutoVacuumShmem->av_signal[AutoVacRebalance])
{
LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
AutoVacuumShmem->av_signal[AutoVacRebalance] = false;
autovac_balance_cost();
LWLockRelease(AutovacuumLock);
}
if (AutoVacuumShmem->av_signal[AutoVacForkFailed])
{
/*
* If the postmaster failed to start a new worker, we sleep
* for a little while and resend the signal. The new worker's
* state is still in memory, so this is sufficient. After
* that, we restart the main loop.
*
* XXX should we put a limit to the number of times we retry?
* I don't think it makes much sense, because a future start
* of a worker will continue to fail in the same way.
*/
AutoVacuumShmem->av_signal[AutoVacForkFailed] = false;
pg_usleep(1000000L); /* 1s */
SendPostmasterSignal(PMSIGNAL_START_AUTOVAC_WORKER);
continue;
}
}
/*
* There are some conditions that we need to check before trying to
* start a launcher. First, we need to make sure that there is a
* launcher slot available. Second, we need to make sure that no
* other worker failed while starting up.
*/
current_time = GetCurrentTimestamp();
LWLockAcquire(AutovacuumLock, LW_SHARED);
can_launch = !dlist_is_empty(&AutoVacuumShmem->av_freeWorkers);
if (AutoVacuumShmem->av_startingWorker != NULL)
{
int waittime;
WorkerInfo worker = AutoVacuumShmem->av_startingWorker;
/*
* We can't launch another worker when another one is still
* starting up (or failed while doing so), so just sleep for a bit
* more; that worker will wake us up again as soon as it's ready.
* We will only wait autovacuum_naptime seconds (up to a maximum
* of 60 seconds) for this to happen however. Note that failure
* to connect to a particular database is not a problem here,
* because the worker removes itself from the startingWorker
* pointer before trying to connect. Problems detected by the
* postmaster (like fork() failure) are also reported and handled
* differently. The only problems that may cause this code to
* fire are errors in the earlier sections of AutoVacWorkerMain,
* before the worker removes the WorkerInfo from the
* startingWorker pointer.
*/
waittime = Min(autovacuum_naptime, 60) * 1000;
if (TimestampDifferenceExceeds(worker->wi_launchtime, current_time,
waittime))
{
LWLockRelease(AutovacuumLock);
LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
/*
* No other process can put a worker in starting mode, so if
* startingWorker is still INVALID after exchanging our lock,
* we assume it's the same one we saw above (so we don't
* recheck the launch time).
*/
if (AutoVacuumShmem->av_startingWorker != NULL)
{
worker = AutoVacuumShmem->av_startingWorker;
worker->wi_dboid = InvalidOid;
worker->wi_tableoid = InvalidOid;
worker->wi_proc = NULL;
worker->wi_launchtime = 0;
dlist_push_head(&AutoVacuumShmem->av_freeWorkers,
&worker->wi_links);
AutoVacuumShmem->av_startingWorker = NULL;
elog(WARNING, "worker took too long to start; canceled");
}
}
else
can_launch = false;
}
LWLockRelease(AutovacuumLock); /* either shared or exclusive */
/* if we can't do anything, just go back to sleep */
if (!can_launch)
continue;
/* We're OK to start a new worker */
if (dlist_is_empty(&DatabaseList))
{
/*
* Special case when the list is empty: start a worker right away.
* This covers the initial case, when no database is in pgstats
* (thus the list is empty). Note that the constraints in
* launcher_determine_sleep keep us from starting workers too
* quickly (at most once every autovacuum_naptime when the list is
* empty).
*/
launch_worker(current_time);
}
else
{
/*
* because rebuild_database_list constructs a list with most
* distant adl_next_worker first, we obtain our database from the
* tail of the list.
*/
avl_dbase *avdb;
avdb = dlist_tail_element(avl_dbase, adl_node, &DatabaseList);
/*
* launch a worker if next_worker is right now or it is in the
* past
*/
if (TimestampDifferenceExceeds(avdb->adl_next_worker,
current_time, 0))
launch_worker(current_time);
}
}
/* Normal exit from the autovac launcher is here */
ereport(LOG,
(errmsg("autovacuum launcher shutting down")));
AutoVacuumShmem->av_launcherpid = 0;
proc_exit(0); /* done */
}
| static void autovacuum_do_vac_analyze | ( | autovac_table * | tab, | |
| BufferAccessStrategy | bstrategy | |||
| ) | [static] |
Definition at line 2736 of file autovacuum.c.
References autovac_table::at_doanalyze, autovac_table::at_dovacuum, autovac_table::at_freeze_min_age, autovac_table::at_freeze_table_age, autovac_table::at_nspname, autovac_table::at_relid, autovac_table::at_relname, autovac_table::at_wraparound, autovac_report_activity(), VacuumStmt::freeze_min_age, VacuumStmt::freeze_table_age, RangeVar::location, MemSet, VacuumStmt::options, VacuumStmt::relation, RangeVar::relname, RangeVar::schemaname, VacuumStmt::type, VacuumStmt::va_cols, and vacuum().
Referenced by do_autovacuum().
{
VacuumStmt vacstmt;
RangeVar rangevar;
/* Set up command parameters --- use local variables instead of palloc */
MemSet(&vacstmt, 0, sizeof(vacstmt));
MemSet(&rangevar, 0, sizeof(rangevar));
rangevar.schemaname = tab->at_nspname;
rangevar.relname = tab->at_relname;
rangevar.location = -1;
vacstmt.type = T_VacuumStmt;
if (!tab->at_wraparound)
vacstmt.options = VACOPT_NOWAIT;
if (tab->at_dovacuum)
vacstmt.options |= VACOPT_VACUUM;
if (tab->at_doanalyze)
vacstmt.options |= VACOPT_ANALYZE;
vacstmt.freeze_min_age = tab->at_freeze_min_age;
vacstmt.freeze_table_age = tab->at_freeze_table_age;
/* we pass the OID, but might need this anyway for an error message */
vacstmt.relation = &rangevar;
vacstmt.va_cols = NIL;
/* Let pgstat know what we're doing */
autovac_report_activity(tab);
vacuum(&vacstmt, tab->at_relid, false, bstrategy, tab->at_wraparound, true);
}
| bool AutoVacuumingActive | ( | void | ) |
Definition at line 2817 of file autovacuum.c.
References autovacuum_start_daemon, and pgstat_track_counts.
Referenced by AutoVacLauncherMain(), reaper(), and ServerLoop().
{
if (!autovacuum_start_daemon || !pgstat_track_counts)
return false;
return true;
}
| void AutoVacuumShmemInit | ( | void | ) |
Definition at line 2881 of file autovacuum.c.
References Assert, autovacuum_max_workers, AutoVacuumShmemSize(), AutoVacuumShmemStruct::av_freeWorkers, AutoVacuumShmemStruct::av_launcherpid, AutoVacuumShmemStruct::av_runningWorkers, AutoVacuumShmemStruct::av_startingWorker, dlist_init(), dlist_push_head(), i, IsUnderPostmaster, MAXALIGN, ShmemInitStruct(), and WorkerInfoData::wi_links.
Referenced by CreateSharedMemoryAndSemaphores().
{
bool found;
AutoVacuumShmem = (AutoVacuumShmemStruct *)
ShmemInitStruct("AutoVacuum Data",
AutoVacuumShmemSize(),
&found);
if (!IsUnderPostmaster)
{
WorkerInfo worker;
int i;
Assert(!found);
AutoVacuumShmem->av_launcherpid = 0;
dlist_init(&AutoVacuumShmem->av_freeWorkers);
dlist_init(&AutoVacuumShmem->av_runningWorkers);
AutoVacuumShmem->av_startingWorker = NULL;
worker = (WorkerInfo) ((char *) AutoVacuumShmem +
MAXALIGN(sizeof(AutoVacuumShmemStruct)));
/* initialize the WorkerInfo free list */
for (i = 0; i < autovacuum_max_workers; i++)
dlist_push_head(&AutoVacuumShmem->av_freeWorkers,
&worker[i].wi_links);
}
else
Assert(found);
}
| Size AutoVacuumShmemSize | ( | void | ) |
Definition at line 2862 of file autovacuum.c.
References add_size(), autovacuum_max_workers, MAXALIGN, and mul_size().
Referenced by AutoVacuumShmemInit(), and CreateSharedMemoryAndSemaphores().
{
Size size;
/*
* Need the fixed struct and the array of WorkerInfoData.
*/
size = sizeof(AutoVacuumShmemStruct);
size = MAXALIGN(size);
size = add_size(size, mul_size(autovacuum_max_workers,
sizeof(WorkerInfoData)));
return size;
}
| void AutoVacuumUpdateDelay | ( | void | ) |
Definition at line 1737 of file autovacuum.c.
References VacuumCostDelay, VacuumCostLimit, WorkerInfoData::wi_cost_delay, and WorkerInfoData::wi_cost_limit.
Referenced by do_autovacuum(), and vacuum_delay_point().
{
if (MyWorkerInfo)
{
VacuumCostDelay = MyWorkerInfo->wi_cost_delay;
VacuumCostLimit = MyWorkerInfo->wi_cost_limit;
}
}
| void AutoVacWorkerFailed | ( | void | ) |
Definition at line 1348 of file autovacuum.c.
References AutoVacuumShmemStruct::av_signal.
Referenced by StartAutovacuumWorker().
{
AutoVacuumShmem->av_signal[AutoVacForkFailed] = true;
}
| NON_EXEC_STATIC void AutoVacWorkerMain | ( | int | argc, | |
| char * | argv[] | |||
| ) |
Definition at line 1474 of file autovacuum.c.
References am_autovacuum_worker, AutovacuumLock, AutoVacuumShmemStruct::av_launcherpid, AutoVacuumShmemStruct::av_runningWorkers, AutoVacuumShmemStruct::av_startingWorker, BaseInit(), DEBUG1, die(), dlist_push_head(), do_autovacuum(), elog, EmitErrorReport(), ereport, errmsg(), FATAL, FloatExceptionHandler(), FreeWorkerInfo(), HOLD_INTERRUPTS, init_ps_display(), InitializeTimeouts(), InitPostgres(), InitProcess(), InitProcessing, IsUnderPostmaster, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MyProc, MyProcPid, MyStartTime, NormalProcessing, NULL, OidIsValid, on_shmem_exit(), PG_exception_stack, PG_SETMASK, pg_usleep(), PGC_S_OVERRIDE, PGC_SUSET, pgstat_report_autovac(), PostAuthDelay, pqsignal(), proc_exit(), procsignal_sigusr1_handler(), quickdie(), ReadNewTransactionId(), ReadNextMultiXactId(), recentMulti, recentXid, set_ps_display(), SetConfigOption(), SetProcessingMode, SIG_DFL, SIG_IGN, SIGCHLD, SIGHUP, sigjmp_buf, SIGPIPE, SIGQUIT, sigsetjmp, SIGUSR1, SIGUSR2, StatementCancelHandler(), synchronous_commit, SYNCHRONOUS_COMMIT_LOCAL_FLUSH, UnBlockSig, WARNING, WorkerInfoData::wi_dboid, WorkerInfoData::wi_links, and WorkerInfoData::wi_proc.
Referenced by StartAutoVacWorker().
{
sigjmp_buf local_sigjmp_buf;
Oid dbid;
/* we are a postmaster subprocess now */
IsUnderPostmaster = true;
am_autovacuum_worker = true;
/* reset MyProcPid */
MyProcPid = getpid();
/* record Start Time for logging */
MyStartTime = time(NULL);
/* Identify myself via ps */
init_ps_display("autovacuum worker process", "", "", "");
SetProcessingMode(InitProcessing);
/*
* If possible, make this process a group leader, so that the postmaster
* can signal any child processes too. (autovacuum probably never has any
* child processes, but for consistency we make all postmaster child
* processes do this.)
*/
#ifdef HAVE_SETSID
if (setsid() < 0)
elog(FATAL, "setsid() failed: %m");
#endif
/*
* Set up signal handlers. We operate on databases much like a regular
* backend, so we use the same signal handling. See equivalent code in
* tcop/postgres.c.
*
* Currently, we don't pay attention to postgresql.conf changes that
* happen during a single daemon iteration, so we can ignore SIGHUP.
*/
pqsignal(SIGHUP, SIG_IGN);
/*
* SIGINT is used to signal canceling the current table's vacuum; SIGTERM
* means abort and exit cleanly, and SIGQUIT means abandon ship.
*/
pqsignal(SIGINT, StatementCancelHandler);
pqsignal(SIGTERM, die);
pqsignal(SIGQUIT, quickdie);
InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
pqsignal(SIGFPE, FloatExceptionHandler);
pqsignal(SIGCHLD, SIG_DFL);
/* Early initialization */
BaseInit();
/*
* Create a per-backend PGPROC struct in shared memory, except in the
* EXEC_BACKEND case where this was done in SubPostmasterMain. We must do
* this before we can use LWLocks (and in the EXEC_BACKEND case we already
* had to do some stuff with LWLocks).
*/
#ifndef EXEC_BACKEND
InitProcess();
#endif
/*
* If an exception is encountered, processing resumes here.
*
* See notes in postgres.c about the design of this coding.
*/
if (sigsetjmp(local_sigjmp_buf, 1) != 0)
{
/* Prevents interrupts while cleaning up */
HOLD_INTERRUPTS();
/* Report the error to the server log */
EmitErrorReport();
/*
* We can now go away. Note that because we called InitProcess, a
* callback was registered to do ProcKill, which will clean up
* necessary state.
*/
proc_exit(0);
}
/* We can now handle ereport(ERROR) */
PG_exception_stack = &local_sigjmp_buf;
PG_SETMASK(&UnBlockSig);
/*
* Force zero_damaged_pages OFF in the autovac process, even if it is set
* in postgresql.conf. We don't really want such a dangerous option being
* applied non-interactively.
*/
SetConfigOption("zero_damaged_pages", "false", PGC_SUSET, PGC_S_OVERRIDE);
/*
* Force statement_timeout and lock_timeout to zero to avoid letting these
* settings prevent regular maintenance from being executed.
*/
SetConfigOption("statement_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
SetConfigOption("lock_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
/*
* Force default_transaction_isolation to READ COMMITTED. We don't want
* to pay the overhead of serializable mode, nor add any risk of causing
* deadlocks or delaying other transactions.
*/
SetConfigOption("default_transaction_isolation", "read committed",
PGC_SUSET, PGC_S_OVERRIDE);
/*
* Force synchronous replication off to allow regular maintenance even if
* we are waiting for standbys to connect. This is important to ensure we
* aren't blocked from performing anti-wraparound tasks.
*/
if (synchronous_commit > SYNCHRONOUS_COMMIT_LOCAL_FLUSH)
SetConfigOption("synchronous_commit", "local",
PGC_SUSET, PGC_S_OVERRIDE);
/*
* Get the info about the database we're going to work on.
*/
LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
/*
* beware of startingWorker being INVALID; this should normally not
* happen, but if a worker fails after forking and before this, the
* launcher might have decided to remove it from the queue and start
* again.
*/
if (AutoVacuumShmem->av_startingWorker != NULL)
{
MyWorkerInfo = AutoVacuumShmem->av_startingWorker;
dbid = MyWorkerInfo->wi_dboid;
MyWorkerInfo->wi_proc = MyProc;
/* insert into the running list */
dlist_push_head(&AutoVacuumShmem->av_runningWorkers,
&MyWorkerInfo->wi_links);
/*
* remove from the "starting" pointer, so that the launcher can start
* a new worker if required
*/
AutoVacuumShmem->av_startingWorker = NULL;
LWLockRelease(AutovacuumLock);
on_shmem_exit(FreeWorkerInfo, 0);
/* wake up the launcher */
if (AutoVacuumShmem->av_launcherpid != 0)
kill(AutoVacuumShmem->av_launcherpid, SIGUSR2);
}
else
{
/* no worker entry for me, go away */
elog(WARNING, "autovacuum worker started without a worker entry");
dbid = InvalidOid;
LWLockRelease(AutovacuumLock);
}
if (OidIsValid(dbid))
{
char dbname[NAMEDATALEN];
/*
* Report autovac startup to the stats collector. We deliberately do
* this before InitPostgres, so that the last_autovac_time will get
* updated even if the connection attempt fails. This is to prevent
* autovac from getting "stuck" repeatedly selecting an unopenable
* database, rather than making any progress on stuff it can connect
* to.
*/
pgstat_report_autovac(dbid);
/*
* Connect to the selected database
*
* Note: if we have selected a just-deleted database (due to using
* stale stats info), we'll fail and exit here.
*/
InitPostgres(NULL, dbid, NULL, dbname);
SetProcessingMode(NormalProcessing);
set_ps_display(dbname, false);
ereport(DEBUG1,
(errmsg("autovacuum: processing database \"%s\"", dbname)));
if (PostAuthDelay)
pg_usleep(PostAuthDelay * 1000000L);
/* And do an appropriate amount of work */
recentXid = ReadNewTransactionId();
recentMulti = ReadNextMultiXactId();
do_autovacuum();
}
/*
* The launcher will be notified of my death in ProcKill, *if* we managed
* to get a worker slot at all
*/
/* All done, go away */
proc_exit(0);
}
| static void avl_sighup_handler | ( | SIGNAL_ARGS | ) | [static] |
Definition at line 1355 of file autovacuum.c.
References got_SIGHUP, MyProc, PGPROC::procLatch, and SetLatch().
Referenced by AutoVacLauncherMain().
{
int save_errno = errno;
got_SIGHUP = true;
if (MyProc)
SetLatch(&MyProc->procLatch);
errno = save_errno;
}
| static void avl_sigterm_handler | ( | SIGNAL_ARGS | ) | [static] |
Definition at line 1381 of file autovacuum.c.
References got_SIGTERM, MyProc, PGPROC::procLatch, and SetLatch().
Referenced by AutoVacLauncherMain().
{
int save_errno = errno;
got_SIGTERM = true;
if (MyProc)
SetLatch(&MyProc->procLatch);
errno = save_errno;
}
| static void avl_sigusr2_handler | ( | SIGNAL_ARGS | ) | [static] |
Definition at line 1368 of file autovacuum.c.
References got_SIGUSR2, MyProc, PGPROC::procLatch, and SetLatch().
Referenced by AutoVacLauncherMain().
{
int save_errno = errno;
got_SIGUSR2 = true;
if (MyProc)
SetLatch(&MyProc->procLatch);
errno = save_errno;
}
| static int db_comparator | ( | const void * | a, | |
| const void * | b | |||
| ) | [static] |
Definition at line 1058 of file autovacuum.c.
Referenced by rebuild_database_list().
| static void do_autovacuum | ( | void | ) | [static] |
Definition at line 1902 of file autovacuum.c.
References AbortOutOfAnyTransaction(), AccessShareLock, ALLOCSET_DEFAULT_INITSIZE, ALLOCSET_DEFAULT_MAXSIZE, ALLOCSET_DEFAULT_MINSIZE, AllocSetContextCreate(), Anum_pg_class_relkind, av_relation::ar_hasrelopts, av_relation::ar_relid, av_relation::ar_reloptions, autovac_table::at_datname, autovac_table::at_dovacuum, autovac_table::at_nspname, autovac_table::at_relid, autovac_table::at_relname, autovac_table::at_vacuum_cost_delay, autovac_table::at_vacuum_cost_limit, autovac_balance_cost(), autovacuum_do_vac_analyze(), AutovacuumLock, AutovacuumScheduleLock, AutoVacuumUpdateDelay(), AutoVacuumShmemStruct::av_runningWorkers, BackendIdGetProc(), BAS_VACUUM, BTEqualStrategyNumber, CharGetDatum, CHECK_FOR_INTERRUPTS, CommitTransactionCommand(), CreateTupleDescCopy(), dlist_iter::cur, DATABASEOID, default_freeze_min_age, default_freeze_table_age, dlist_container, dlist_foreach, DROP_CASCADE, elog, EmitErrorReport(), HASHCTL::entrysize, ereport, errcontext, errmsg(), ERROR, extract_autovac_opts(), FlushErrorState(), ForwardScanDirection, get_database_name(), get_namespace_name(), get_pgstat_tabentry_relid(), get_rel_name(), get_rel_namespace(), GetAccessStrategy(), GETSTRUCT, GetTempNamespaceBackendId(), HASHCTL::hash, hash_create(), HASH_ELEM, HASH_ENTER, HASH_FIND, HASH_FUNCTION, hash_search(), heap_beginscan(), heap_close, heap_endscan(), heap_getnext(), heap_open(), HeapTupleGetOid, HeapTupleIsValid, HOLD_INTERRUPTS, InvalidOid, HASHCTL::keysize, lappend_oid(), lfirst_oid, LOG, LW_EXCLUSIVE, LW_SHARED, LWLockAcquire(), LWLockRelease(), MemoryContextResetAndDeleteChildren(), MemoryContextSwitchTo(), MemSet, MyBackendId, MyDatabaseId, NameStr, NULL, ObjectIdGetDatum, OidIsValid, PERFORM_DELETION_INTERNAL, performDeletion(), pfree(), PG_CATCH, PG_END_TRY, PG_TRY, pgstat_fetch_stat_dbentry(), pgstat_vacuum_stat(), PortalContext, QueryCancelPending, relation_needs_vacanalyze(), RelationGetDescr, RelationRelationId, ReleaseSysCache(), RELKIND_MATVIEW, RELKIND_RELATION, RELKIND_TOASTVALUE, RELPERSISTENCE_TEMP, RESUME_INTERRUPTS, ScanKeyInit(), SearchSysCache1, SnapshotNow, StartTransactionCommand(), table_recheck_autovac(), TopMemoryContext, TopTransactionContext, vac_update_datfrozenxid(), vacuum_freeze_min_age, vacuum_freeze_table_age, VacuumCostDelay, VacuumCostLimit, WorkerInfoData::wi_cost_delay, WorkerInfoData::wi_cost_limit, WorkerInfoData::wi_cost_limit_base, WorkerInfoData::wi_dboid, and WorkerInfoData::wi_tableoid.
Referenced by AutoVacWorkerMain().
{
Relation classRel;
HeapTuple tuple;
HeapScanDesc relScan;
Form_pg_database dbForm;
List *table_oids = NIL;
HASHCTL ctl;
HTAB *table_toast_map;
ListCell *volatile cell;
PgStat_StatDBEntry *shared;
PgStat_StatDBEntry *dbentry;
BufferAccessStrategy bstrategy;
ScanKeyData key;
TupleDesc pg_class_desc;
/*
* StartTransactionCommand and CommitTransactionCommand will automatically
* switch to other contexts. We need this one to keep the list of
* relations to vacuum/analyze across transactions.
*/
AutovacMemCxt = AllocSetContextCreate(TopMemoryContext,
"AV worker",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
MemoryContextSwitchTo(AutovacMemCxt);
/*
* may be NULL if we couldn't find an entry (only happens if we are
* forcing a vacuum for anti-wrap purposes).
*/
dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
/* Start a transaction so our commands have one to play into. */
StartTransactionCommand();
/*
* Clean up any dead statistics collector entries for this DB. We always
* want to do this exactly once per DB-processing cycle, even if we find
* nothing worth vacuuming in the database.
*/
pgstat_vacuum_stat();
/*
* Find the pg_database entry and select the default freeze ages. We use
* zero in template and nonconnectable databases, else the system-wide
* default.
*/
tuple = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(MyDatabaseId));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for database %u", MyDatabaseId);
dbForm = (Form_pg_database) GETSTRUCT(tuple);
if (dbForm->datistemplate || !dbForm->datallowconn)
{
default_freeze_min_age = 0;
default_freeze_table_age = 0;
}
else
{
default_freeze_min_age = vacuum_freeze_min_age;
default_freeze_table_age = vacuum_freeze_table_age;
}
ReleaseSysCache(tuple);
/* StartTransactionCommand changed elsewhere */
MemoryContextSwitchTo(AutovacMemCxt);
/* The database hash where pgstat keeps shared relations */
shared = pgstat_fetch_stat_dbentry(InvalidOid);
classRel = heap_open(RelationRelationId, AccessShareLock);
/* create a copy so we can use it after closing pg_class */
pg_class_desc = CreateTupleDescCopy(RelationGetDescr(classRel));
/* create hash table for toast <-> main relid mapping */
MemSet(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(Oid);
ctl.entrysize = sizeof(av_relation);
ctl.hash = oid_hash;
table_toast_map = hash_create("TOAST to main relid map",
100,
&ctl,
HASH_ELEM | HASH_FUNCTION);
/*
* Scan pg_class to determine which tables to vacuum.
*
* We do this in two passes: on the first one we collect the list of plain
* relations and materialized views, and on the second one we collect
* TOAST tables. The reason for doing the second pass is that during it we
* want to use the main relation's pg_class.reloptions entry if the TOAST
* table does not have any, and we cannot obtain it unless we know
* beforehand what's the main table OID.
*
* We need to check TOAST tables separately because in cases with short,
* wide tables there might be proportionally much more activity in the
* TOAST table than in its parent.
*/
relScan = heap_beginscan(classRel, SnapshotNow, 0, NULL);
/*
* On the first pass, we collect main tables to vacuum, and also the main
* table relid to TOAST relid mapping.
*/
while ((tuple = heap_getnext(relScan, ForwardScanDirection)) != NULL)
{
Form_pg_class classForm = (Form_pg_class) GETSTRUCT(tuple);
PgStat_StatTabEntry *tabentry;
AutoVacOpts *relopts;
Oid relid;
bool dovacuum;
bool doanalyze;
bool wraparound;
if (classForm->relkind != RELKIND_RELATION &&
classForm->relkind != RELKIND_MATVIEW)
continue;
relid = HeapTupleGetOid(tuple);
/* Fetch reloptions and the pgstat entry for this table */
relopts = extract_autovac_opts(tuple, pg_class_desc);
tabentry = get_pgstat_tabentry_relid(relid, classForm->relisshared,
shared, dbentry);
/* Check if it needs vacuum or analyze */
relation_needs_vacanalyze(relid, relopts, classForm, tabentry,
&dovacuum, &doanalyze, &wraparound);
/*
* Check if it is a temp table (presumably, of some other backend's).
* We cannot safely process other backends' temp tables.
*/
if (classForm->relpersistence == RELPERSISTENCE_TEMP)
{
int backendID;
backendID = GetTempNamespaceBackendId(classForm->relnamespace);
/* We just ignore it if the owning backend is still active */
if (backendID == MyBackendId || BackendIdGetProc(backendID) == NULL)
{
/*
* We found an orphan temp table (which was probably left
* behind by a crashed backend). If it's so old as to need
* vacuum for wraparound, forcibly drop it. Otherwise just
* log a complaint.
*/
if (wraparound)
{
ObjectAddress object;
ereport(LOG,
(errmsg("autovacuum: dropping orphan temp table \"%s\".\"%s\" in database \"%s\"",
get_namespace_name(classForm->relnamespace),
NameStr(classForm->relname),
get_database_name(MyDatabaseId))));
object.classId = RelationRelationId;
object.objectId = relid;
object.objectSubId = 0;
performDeletion(&object, DROP_CASCADE, PERFORM_DELETION_INTERNAL);
}
else
{
ereport(LOG,
(errmsg("autovacuum: found orphan temp table \"%s\".\"%s\" in database \"%s\"",
get_namespace_name(classForm->relnamespace),
NameStr(classForm->relname),
get_database_name(MyDatabaseId))));
}
}
}
else
{
/* relations that need work are added to table_oids */
if (dovacuum || doanalyze)
table_oids = lappend_oid(table_oids, relid);
/*
* Remember the association for the second pass. Note: we must do
* this even if the table is going to be vacuumed, because we
* don't automatically vacuum toast tables along the parent table.
*/
if (OidIsValid(classForm->reltoastrelid))
{
av_relation *hentry;
bool found;
hentry = hash_search(table_toast_map,
&classForm->reltoastrelid,
HASH_ENTER, &found);
if (!found)
{
/* hash_search already filled in the key */
hentry->ar_relid = relid;
hentry->ar_hasrelopts = false;
if (relopts != NULL)
{
hentry->ar_hasrelopts = true;
memcpy(&hentry->ar_reloptions, relopts,
sizeof(AutoVacOpts));
}
}
}
}
}
heap_endscan(relScan);
/* second pass: check TOAST tables */
ScanKeyInit(&key,
Anum_pg_class_relkind,
BTEqualStrategyNumber, F_CHAREQ,
CharGetDatum(RELKIND_TOASTVALUE));
relScan = heap_beginscan(classRel, SnapshotNow, 1, &key);
while ((tuple = heap_getnext(relScan, ForwardScanDirection)) != NULL)
{
Form_pg_class classForm = (Form_pg_class) GETSTRUCT(tuple);
PgStat_StatTabEntry *tabentry;
Oid relid;
AutoVacOpts *relopts = NULL;
bool dovacuum;
bool doanalyze;
bool wraparound;
/*
* We cannot safely process other backends' temp tables, so skip 'em.
*/
if (classForm->relpersistence == RELPERSISTENCE_TEMP)
continue;
relid = HeapTupleGetOid(tuple);
/*
* fetch reloptions -- if this toast table does not have them, try the
* main rel
*/
relopts = extract_autovac_opts(tuple, pg_class_desc);
if (relopts == NULL)
{
av_relation *hentry;
bool found;
hentry = hash_search(table_toast_map, &relid, HASH_FIND, &found);
if (found && hentry->ar_hasrelopts)
relopts = &hentry->ar_reloptions;
}
/* Fetch the pgstat entry for this table */
tabentry = get_pgstat_tabentry_relid(relid, classForm->relisshared,
shared, dbentry);
relation_needs_vacanalyze(relid, relopts, classForm, tabentry,
&dovacuum, &doanalyze, &wraparound);
/* ignore analyze for toast tables */
if (dovacuum)
table_oids = lappend_oid(table_oids, relid);
}
heap_endscan(relScan);
heap_close(classRel, AccessShareLock);
/*
* Create a buffer access strategy object for VACUUM to use. We want to
* use the same one across all the vacuum operations we perform, since the
* point is for VACUUM not to blow out the shared cache.
*/
bstrategy = GetAccessStrategy(BAS_VACUUM);
/*
* create a memory context to act as fake PortalContext, so that the
* contexts created in the vacuum code are cleaned up for each table.
*/
PortalContext = AllocSetContextCreate(AutovacMemCxt,
"Autovacuum Portal",
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
/*
* Perform operations on collected tables.
*/
foreach(cell, table_oids)
{
Oid relid = lfirst_oid(cell);
autovac_table *tab;
bool skipit;
int stdVacuumCostDelay;
int stdVacuumCostLimit;
dlist_iter iter;
CHECK_FOR_INTERRUPTS();
/*
* hold schedule lock from here until we're sure that this table still
* needs vacuuming. We also need the AutovacuumLock to walk the
* worker array, but we'll let go of that one quickly.
*/
LWLockAcquire(AutovacuumScheduleLock, LW_EXCLUSIVE);
LWLockAcquire(AutovacuumLock, LW_SHARED);
/*
* Check whether the table is being vacuumed concurrently by another
* worker.
*/
skipit = false;
dlist_foreach(iter, &AutoVacuumShmem->av_runningWorkers)
{
WorkerInfo worker = dlist_container(WorkerInfoData, wi_links, iter.cur);
/* ignore myself */
if (worker == MyWorkerInfo)
continue;
/* ignore workers in other databases */
if (worker->wi_dboid != MyDatabaseId)
continue;
if (worker->wi_tableoid == relid)
{
skipit = true;
break;
}
}
LWLockRelease(AutovacuumLock);
if (skipit)
{
LWLockRelease(AutovacuumScheduleLock);
continue;
}
/*
* Check whether pgstat data still says we need to vacuum this table.
* It could have changed if something else processed the table while
* we weren't looking.
*
* Note: we have a special case in pgstat code to ensure that the
* stats we read are as up-to-date as possible, to avoid the problem
* that somebody just finished vacuuming this table. The window to
* the race condition is not closed but it is very small.
*/
MemoryContextSwitchTo(AutovacMemCxt);
tab = table_recheck_autovac(relid, table_toast_map, pg_class_desc);
if (tab == NULL)
{
/* someone else vacuumed the table, or it went away */
LWLockRelease(AutovacuumScheduleLock);
continue;
}
/*
* Ok, good to go. Store the table in shared memory before releasing
* the lock so that other workers don't vacuum it concurrently.
*/
MyWorkerInfo->wi_tableoid = relid;
LWLockRelease(AutovacuumScheduleLock);
/*
* Remember the prevailing values of the vacuum cost GUCs. We have to
* restore these at the bottom of the loop, else we'll compute wrong
* values in the next iteration of autovac_balance_cost().
*/
stdVacuumCostDelay = VacuumCostDelay;
stdVacuumCostLimit = VacuumCostLimit;
/* Must hold AutovacuumLock while mucking with cost balance info */
LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
/* advertise my cost delay parameters for the balancing algorithm */
MyWorkerInfo->wi_cost_delay = tab->at_vacuum_cost_delay;
MyWorkerInfo->wi_cost_limit = tab->at_vacuum_cost_limit;
MyWorkerInfo->wi_cost_limit_base = tab->at_vacuum_cost_limit;
/* do a balance */
autovac_balance_cost();
/* set the active cost parameters from the result of that */
AutoVacuumUpdateDelay();
/* done */
LWLockRelease(AutovacuumLock);
/* clean up memory before each iteration */
MemoryContextResetAndDeleteChildren(PortalContext);
/*
* Save the relation name for a possible error message, to avoid a
* catalog lookup in case of an error. If any of these return NULL,
* then the relation has been dropped since last we checked; skip it.
* Note: they must live in a long-lived memory context because we call
* vacuum and analyze in different transactions.
*/
tab->at_relname = get_rel_name(tab->at_relid);
tab->at_nspname = get_namespace_name(get_rel_namespace(tab->at_relid));
tab->at_datname = get_database_name(MyDatabaseId);
if (!tab->at_relname || !tab->at_nspname || !tab->at_datname)
goto deleted;
/*
* We will abort vacuuming the current table if something errors out,
* and continue with the next one in schedule; in particular, this
* happens if we are interrupted with SIGINT.
*/
PG_TRY();
{
/* have at it */
MemoryContextSwitchTo(TopTransactionContext);
autovacuum_do_vac_analyze(tab, bstrategy);
/*
* Clear a possible query-cancel signal, to avoid a late reaction
* to an automatically-sent signal because of vacuuming the
* current table (we're done with it, so it would make no sense to
* cancel at this point.)
*/
QueryCancelPending = false;
}
PG_CATCH();
{
/*
* Abort the transaction, start a new one, and proceed with the
* next table in our list.
*/
HOLD_INTERRUPTS();
if (tab->at_dovacuum)
errcontext("automatic vacuum of table \"%s.%s.%s\"",
tab->at_datname, tab->at_nspname, tab->at_relname);
else
errcontext("automatic analyze of table \"%s.%s.%s\"",
tab->at_datname, tab->at_nspname, tab->at_relname);
EmitErrorReport();
/* this resets the PGXACT flags too */
AbortOutOfAnyTransaction();
FlushErrorState();
MemoryContextResetAndDeleteChildren(PortalContext);
/* restart our transaction for the following operations */
StartTransactionCommand();
RESUME_INTERRUPTS();
}
PG_END_TRY();
/* the PGXACT flags are reset at the next end of transaction */
/* be tidy */
deleted:
if (tab->at_datname != NULL)
pfree(tab->at_datname);
if (tab->at_nspname != NULL)
pfree(tab->at_nspname);
if (tab->at_relname != NULL)
pfree(tab->at_relname);
pfree(tab);
/*
* Remove my info from shared memory. We could, but intentionally
* don't, clear wi_cost_limit and friends --- this is on the
* assumption that we probably have more to do with similar cost
* settings, so we don't want to give up our share of I/O for a very
* short interval and thereby thrash the global balance.
*/
LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
MyWorkerInfo->wi_tableoid = InvalidOid;
LWLockRelease(AutovacuumLock);
/* restore vacuum cost GUCs for the next iteration */
VacuumCostDelay = stdVacuumCostDelay;
VacuumCostLimit = stdVacuumCostLimit;
}
/*
* We leak table_toast_map here (among other things), but since we're
* going away soon, it's not a problem.
*/
/*
* Update pg_database.datfrozenxid, and truncate pg_clog if possible. We
* only need to do this once, not after each table.
*/
vac_update_datfrozenxid();
/* Finally close out the last transaction. */
CommitTransactionCommand();
}
| static Oid do_start_worker | ( | void | ) | [static] |
Definition at line 1078 of file autovacuum.c.
References avl_dbase::adl_datid, avl_dbase::adl_next_worker, avw_dbase::adw_datid, avw_dbase::adw_entry, avw_dbase::adw_frozenmulti, avw_dbase::adw_frozenxid, ALLOCSET_DEFAULT_INITSIZE, ALLOCSET_DEFAULT_MAXSIZE, ALLOCSET_DEFAULT_MINSIZE, AllocSetContextCreate(), autovac_refresh_stats(), autovacuum_freeze_max_age, autovacuum_naptime, AutovacuumLock, AutoVacuumShmemStruct::av_freeWorkers, AutoVacuumShmemStruct::av_startingWorker, dlist_iter::cur, CurrentMemoryContext, dblist, dlist_container, dlist_is_empty(), dlist_pop_head_node(), dlist_reverse_foreach, FirstMultiXactId, FirstNormalTransactionId, get_database_list(), GetCurrentTimestamp(), InvalidOid, PgStat_StatDBEntry::last_autovac_time, lfirst, LW_EXCLUSIVE, LW_SHARED, LWLockAcquire(), LWLockRelease(), MemoryContextDelete(), MemoryContextSwitchTo(), MultiXactIdPrecedes(), NULL, pgstat_fetch_stat_dbentry(), PMSIGNAL_START_AUTOVAC_WORKER, ReadNewTransactionId(), ReadNextMultiXactId(), rebuild_database_list(), recentMulti, recentXid, SendPostmasterSignal(), TimestampDifferenceExceeds(), TransactionIdPrecedes(), WorkerInfoData::wi_dboid, WorkerInfoData::wi_launchtime, and WorkerInfoData::wi_proc.
Referenced by AutoVacLauncherMain(), and launch_worker().
{
List *dblist;
ListCell *cell;
TransactionId xidForceLimit;
MultiXactId multiForceLimit;
bool for_xid_wrap;
bool for_multi_wrap;
avw_dbase *avdb;
TimestampTz current_time;
bool skipit = false;
Oid retval = InvalidOid;
MemoryContext tmpcxt,
oldcxt;
/* return quickly when there are no free workers */
LWLockAcquire(AutovacuumLock, LW_SHARED);
if (dlist_is_empty(&AutoVacuumShmem->av_freeWorkers))
{
LWLockRelease(AutovacuumLock);
return InvalidOid;
}
LWLockRelease(AutovacuumLock);
/*
* Create and switch to a temporary context to avoid leaking the memory
* allocated for the database list.
*/
tmpcxt = AllocSetContextCreate(CurrentMemoryContext,
"Start worker tmp cxt",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
oldcxt = MemoryContextSwitchTo(tmpcxt);
/* use fresh stats */
autovac_refresh_stats();
/* Get a list of databases */
dblist = get_database_list();
/*
* Determine the oldest datfrozenxid/relfrozenxid that we will allow to
* pass without forcing a vacuum. (This limit can be tightened for
* particular tables, but not loosened.)
*/
recentXid = ReadNewTransactionId();
xidForceLimit = recentXid - autovacuum_freeze_max_age;
/* ensure it's a "normal" XID, else TransactionIdPrecedes misbehaves */
/* this can cause the limit to go backwards by 3, but that's OK */
if (xidForceLimit < FirstNormalTransactionId)
xidForceLimit -= FirstNormalTransactionId;
/* Also determine the oldest datminmxid we will consider. */
recentMulti = ReadNextMultiXactId();
multiForceLimit = recentMulti - autovacuum_freeze_max_age;
if (multiForceLimit < FirstMultiXactId)
multiForceLimit -= FirstMultiXactId;
/*
* Choose a database to connect to. We pick the database that was least
* recently auto-vacuumed, or one that needs vacuuming to prevent Xid
* wraparound-related data loss. If any db at risk of Xid wraparound is
* found, we pick the one with oldest datfrozenxid, independently of
* autovacuum times; similarly we pick the one with the oldest datminmxid
* if any is in MultiXactId wraparound. Note that those in Xid wraparound
* danger are given more priority than those in multi wraparound danger.
*
* Note that a database with no stats entry is not considered, except for
* Xid wraparound purposes. The theory is that if no one has ever
* connected to it since the stats were last initialized, it doesn't need
* vacuuming.
*
* XXX This could be improved if we had more info about whether it needs
* vacuuming before connecting to it. Perhaps look through the pgstats
* data for the database's tables? One idea is to keep track of the
* number of new and dead tuples per database in pgstats. However it
* isn't clear how to construct a metric that measures that and not cause
* starvation for less busy databases.
*/
avdb = NULL;
for_xid_wrap = false;
for_multi_wrap = false;
current_time = GetCurrentTimestamp();
foreach(cell, dblist)
{
avw_dbase *tmp = lfirst(cell);
dlist_iter iter;
/* Check to see if this one is at risk of wraparound */
if (TransactionIdPrecedes(tmp->adw_frozenxid, xidForceLimit))
{
if (avdb == NULL ||
TransactionIdPrecedes(tmp->adw_frozenxid,
avdb->adw_frozenxid))
avdb = tmp;
for_xid_wrap = true;
continue;
}
else if (for_xid_wrap)
continue; /* ignore not-at-risk DBs */
else if (MultiXactIdPrecedes(tmp->adw_frozenmulti, multiForceLimit))
{
if (avdb == NULL ||
MultiXactIdPrecedes(tmp->adw_frozenmulti,
avdb->adw_frozenmulti))
avdb = tmp;
for_multi_wrap = true;
continue;
}
else if (for_multi_wrap)
continue; /* ignore not-at-risk DBs */
/* Find pgstat entry if any */
tmp->adw_entry = pgstat_fetch_stat_dbentry(tmp->adw_datid);
/*
* Skip a database with no pgstat entry; it means it hasn't seen any
* activity.
*/
if (!tmp->adw_entry)
continue;
/*
* Also, skip a database that appears on the database list as having
* been processed recently (less than autovacuum_naptime seconds ago).
* We do this so that we don't select a database which we just
* selected, but that pgstat hasn't gotten around to updating the last
* autovacuum time yet.
*/
skipit = false;
dlist_reverse_foreach(iter, &DatabaseList)
{
avl_dbase *dbp = dlist_container(avl_dbase, adl_node, iter.cur);
if (dbp->adl_datid == tmp->adw_datid)
{
/*
* Skip this database if its next_worker value falls between
* the current time and the current time plus naptime.
*/
if (!TimestampDifferenceExceeds(dbp->adl_next_worker,
current_time, 0) &&
!TimestampDifferenceExceeds(current_time,
dbp->adl_next_worker,
autovacuum_naptime * 1000))
skipit = true;
break;
}
}
if (skipit)
continue;
/*
* Remember the db with oldest autovac time. (If we are here, both
* tmp->entry and db->entry must be non-null.)
*/
if (avdb == NULL ||
tmp->adw_entry->last_autovac_time < avdb->adw_entry->last_autovac_time)
avdb = tmp;
}
/* Found a database -- process it */
if (avdb != NULL)
{
WorkerInfo worker;
dlist_node *wptr;
LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
/*
* Get a worker entry from the freelist. We checked above, so there
* really should be a free slot.
*/
wptr = dlist_pop_head_node(&AutoVacuumShmem->av_freeWorkers);
worker = dlist_container(WorkerInfoData, wi_links, wptr);
worker->wi_dboid = avdb->adw_datid;
worker->wi_proc = NULL;
worker->wi_launchtime = GetCurrentTimestamp();
AutoVacuumShmem->av_startingWorker = worker;
LWLockRelease(AutovacuumLock);
SendPostmasterSignal(PMSIGNAL_START_AUTOVAC_WORKER);
retval = avdb->adw_datid;
}
else if (skipit)
{
/*
* If we skipped all databases on the list, rebuild it, because it
* probably contains a dropped database.
*/
rebuild_database_list(InvalidOid);
}
MemoryContextSwitchTo(oldcxt);
MemoryContextDelete(tmpcxt);
return retval;
}
| static AutoVacOpts * extract_autovac_opts | ( | HeapTuple | tup, | |
| TupleDesc | pg_class_desc | |||
| ) | [static] |
Definition at line 2404 of file autovacuum.c.
References Assert, extractRelOptions(), GETSTRUCT, InvalidOid, NULL, palloc(), pfree(), RELKIND_MATVIEW, RELKIND_RELATION, and RELKIND_TOASTVALUE.
Referenced by do_autovacuum(), and table_recheck_autovac().
{
bytea *relopts;
AutoVacOpts *av;
Assert(((Form_pg_class) GETSTRUCT(tup))->relkind == RELKIND_RELATION ||
((Form_pg_class) GETSTRUCT(tup))->relkind == RELKIND_MATVIEW ||
((Form_pg_class) GETSTRUCT(tup))->relkind == RELKIND_TOASTVALUE);
relopts = extractRelOptions(tup, pg_class_desc, InvalidOid);
if (relopts == NULL)
return NULL;
av = palloc(sizeof(AutoVacOpts));
memcpy(av, &(((StdRdOptions *) relopts)->autovacuum), sizeof(AutoVacOpts));
pfree(relopts);
return av;
}
| static void FreeWorkerInfo | ( | int | code, | |
| Datum | arg | |||
| ) | [static] |
Definition at line 1690 of file autovacuum.c.
References AutovacuumLauncherPid, AutovacuumLock, AutoVacuumShmemStruct::av_freeWorkers, AutoVacuumShmemStruct::av_launcherpid, AutoVacuumShmemStruct::av_signal, dlist_delete(), dlist_push_head(), LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), NULL, WorkerInfoData::wi_cost_delay, WorkerInfoData::wi_cost_limit, WorkerInfoData::wi_cost_limit_base, WorkerInfoData::wi_dboid, WorkerInfoData::wi_launchtime, WorkerInfoData::wi_links, WorkerInfoData::wi_proc, and WorkerInfoData::wi_tableoid.
Referenced by AutoVacWorkerMain().
{
if (MyWorkerInfo != NULL)
{
LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
/*
* Wake the launcher up so that he can launch a new worker immediately
* if required. We only save the launcher's PID in local memory here;
* the actual signal will be sent when the PGPROC is recycled. Note
* that we always do this, so that the launcher can rebalance the cost
* limit setting of the remaining workers.
*
* We somewhat ignore the risk that the launcher changes its PID
* between us reading it and the actual kill; we expect ProcKill to be
* called shortly after us, and we assume that PIDs are not reused too
* quickly after a process exits.
*/
AutovacuumLauncherPid = AutoVacuumShmem->av_launcherpid;
dlist_delete(&MyWorkerInfo->wi_links);
MyWorkerInfo->wi_dboid = InvalidOid;
MyWorkerInfo->wi_tableoid = InvalidOid;
MyWorkerInfo->wi_proc = NULL;
MyWorkerInfo->wi_launchtime = 0;
MyWorkerInfo->wi_cost_delay = 0;
MyWorkerInfo->wi_cost_limit = 0;
MyWorkerInfo->wi_cost_limit_base = 0;
dlist_push_head(&AutoVacuumShmem->av_freeWorkers,
&MyWorkerInfo->wi_links);
/* not mine anymore */
MyWorkerInfo = NULL;
/*
* now that we're inactive, cause a rebalancing of the surviving
* workers
*/
AutoVacuumShmem->av_signal[AutoVacRebalance] = true;
LWLockRelease(AutovacuumLock);
}
}
| static List * get_database_list | ( | void | ) | [static] |
Definition at line 1836 of file autovacuum.c.
References AccessShareLock, avw_dbase::adw_datid, avw_dbase::adw_entry, avw_dbase::adw_frozenmulti, avw_dbase::adw_frozenxid, avw_dbase::adw_name, CommitTransactionCommand(), CurrentMemoryContext, DatabaseRelationId, dblist, ForwardScanDirection, GETSTRUCT, GetTransactionSnapshot(), heap_beginscan(), heap_close, heap_endscan(), heap_getnext(), heap_open(), HeapTupleGetOid, HeapTupleIsValid, lappend(), MemoryContextSwitchTo(), NameStr, NULL, palloc(), pstrdup(), SnapshotNow, and StartTransactionCommand().
Referenced by do_start_worker(), and rebuild_database_list().
{
List *dblist = NIL;
Relation rel;
HeapScanDesc scan;
HeapTuple tup;
MemoryContext resultcxt;
/* This is the context that we will allocate our output data in */
resultcxt = CurrentMemoryContext;
/*
* Start a transaction so we can access pg_database, and get a snapshot.
* We don't have a use for the snapshot itself, but we're interested in
* the secondary effect that it sets RecentGlobalXmin. (This is critical
* for anything that reads heap pages, because HOT may decide to prune
* them even if the process doesn't attempt to modify any tuples.)
*/
StartTransactionCommand();
(void) GetTransactionSnapshot();
rel = heap_open(DatabaseRelationId, AccessShareLock);
scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
while (HeapTupleIsValid(tup = heap_getnext(scan, ForwardScanDirection)))
{
Form_pg_database pgdatabase = (Form_pg_database) GETSTRUCT(tup);
avw_dbase *avdb;
MemoryContext oldcxt;
/*
* Allocate our results in the caller's context, not the
* transaction's. We do this inside the loop, and restore the original
* context at the end, so that leaky things like heap_getnext() are
* not called in a potentially long-lived context.
*/
oldcxt = MemoryContextSwitchTo(resultcxt);
avdb = (avw_dbase *) palloc(sizeof(avw_dbase));
avdb->adw_datid = HeapTupleGetOid(tup);
avdb->adw_name = pstrdup(NameStr(pgdatabase->datname));
avdb->adw_frozenxid = pgdatabase->datfrozenxid;
avdb->adw_frozenmulti = pgdatabase->datminmxid;
/* this gets set later: */
avdb->adw_entry = NULL;
dblist = lappend(dblist, avdb);
MemoryContextSwitchTo(oldcxt);
}
heap_endscan(scan);
heap_close(rel, AccessShareLock);
CommitTransactionCommand();
return dblist;
}
| static PgStat_StatTabEntry * get_pgstat_tabentry_relid | ( | Oid | relid, | |
| bool | isshared, | |||
| PgStat_StatDBEntry * | shared, | |||
| PgStat_StatDBEntry * | dbentry | |||
| ) | [static] |
Definition at line 2430 of file autovacuum.c.
References HASH_FIND, hash_search(), NULL, PointerIsValid, and PgStat_StatDBEntry::tables.
Referenced by do_autovacuum(), and table_recheck_autovac().
{
PgStat_StatTabEntry *tabentry = NULL;
if (isshared)
{
if (PointerIsValid(shared))
tabentry = hash_search(shared->tables, &relid,
HASH_FIND, NULL);
}
else if (PointerIsValid(dbentry))
tabentry = hash_search(dbentry->tables, &relid,
HASH_FIND, NULL);
return tabentry;
}
| bool IsAutoVacuumLauncherProcess | ( | void | ) |
Definition at line 2845 of file autovacuum.c.
References am_autovacuum_launcher.
Referenced by autovac_refresh_stats(), backend_read_statsfile(), InitPostgres(), InitProcess(), and ProcKill().
{
return am_autovacuum_launcher;
}
| bool IsAutoVacuumWorkerProcess | ( | void | ) |
Definition at line 2851 of file autovacuum.c.
References am_autovacuum_worker.
Referenced by analyze_rel(), backend_read_statsfile(), CheckMyDatabase(), do_analyze_rel(), ginvacuumcleanup(), InitializeSessionUserIdStandalone(), InitPostgres(), InitProcess(), lazy_vacuum_rel(), pgstat_report_analyze(), pgstat_report_vacuum(), proc_exit(), ProcessInterrupts(), vacuum(), and vacuum_rel().
{
return am_autovacuum_worker;
}
| static void launch_worker | ( | TimestampTz | now | ) | [static] |
Definition at line 1296 of file autovacuum.c.
References avl_dbase::adl_datid, avl_dbase::adl_next_worker, autovacuum_naptime, dlist_iter::cur, dlist_container, dlist_foreach, dlist_move_head(), do_start_worker(), OidIsValid, rebuild_database_list(), and TimestampTzPlusMilliseconds.
Referenced by AutoVacLauncherMain().
{
Oid dbid;
dlist_iter iter;
dbid = do_start_worker();
if (OidIsValid(dbid))
{
bool found = false;
/*
* Walk the database list and update the corresponding entry. If the
* database is not on the list, we'll recreate the list.
*/
dlist_foreach(iter, &DatabaseList)
{
avl_dbase *avdb = dlist_container(avl_dbase, adl_node, iter.cur);
if (avdb->adl_datid == dbid)
{
found = true;
/*
* add autovacuum_naptime seconds to the current time, and use
* that as the new "next_worker" field for this database.
*/
avdb->adl_next_worker =
TimestampTzPlusMilliseconds(now, autovacuum_naptime * 1000);
dlist_move_head(&DatabaseList, iter.cur);
break;
}
}
/*
* If the database was not present in the database list, we rebuild
* the list. It's possible that the database does not get into the
* list anyway, for example if it's a database that doesn't have a
* pgstat entry, but this is not a problem because we don't want to
* schedule workers regularly into those in any case.
*/
if (!found)
rebuild_database_list(dbid);
}
}
| static void launcher_determine_sleep | ( | bool | canlaunch, | |
| bool | recursing, | |||
| struct timeval * | nap | |||
| ) | [static] |
Definition at line 797 of file autovacuum.c.
References avl_dbase::adl_next_worker, autovacuum_naptime, dlist_is_empty(), dlist_tail_element, GetCurrentTimestamp(), InvalidOid, MIN_AUTOVAC_SLEEPTIME, rebuild_database_list(), and TimestampDifference().
Referenced by AutoVacLauncherMain().
{
/*
* We sleep until the next scheduled vacuum. We trust that when the
* database list was built, care was taken so that no entries have times
* in the past; if the first entry has too close a next_worker value, or a
* time in the past, we will sleep a small nominal time.
*/
if (!canlaunch)
{
nap->tv_sec = autovacuum_naptime;
nap->tv_usec = 0;
}
else if (!dlist_is_empty(&DatabaseList))
{
TimestampTz current_time = GetCurrentTimestamp();
TimestampTz next_wakeup;
avl_dbase *avdb;
long secs;
int usecs;
avdb = dlist_tail_element(avl_dbase, adl_node, &DatabaseList);
next_wakeup = avdb->adl_next_worker;
TimestampDifference(current_time, next_wakeup, &secs, &usecs);
nap->tv_sec = secs;
nap->tv_usec = usecs;
}
else
{
/* list is empty, sleep for whole autovacuum_naptime seconds */
nap->tv_sec = autovacuum_naptime;
nap->tv_usec = 0;
}
/*
* If the result is exactly zero, it means a database had an entry with
* time in the past. Rebuild the list so that the databases are evenly
* distributed again, and recalculate the time to sleep. This can happen
* if there are more tables needing vacuum than workers, and they all take
* longer to vacuum than autovacuum_naptime.
*
* We only recurse once. rebuild_database_list should always return times
* in the future, but it seems best not to trust too much on that.
*/
if (nap->tv_sec == 0 && nap->tv_usec == 0 && !recursing)
{
rebuild_database_list(InvalidOid);
launcher_determine_sleep(canlaunch, true, nap);
return;
}
/* The smallest time we'll allow the launcher to sleep. */
if (nap->tv_sec <= 0 && nap->tv_usec <= MIN_AUTOVAC_SLEEPTIME * 1000)
{
nap->tv_sec = 0;
nap->tv_usec = MIN_AUTOVAC_SLEEPTIME * 1000;
}
}
| static void rebuild_database_list | ( | Oid | newdb | ) | [static] |
Definition at line 872 of file autovacuum.c.
References avl_dbase::adl_datid, avl_dbase::adl_next_worker, avl_dbase::adl_node, avl_dbase::adl_score, avw_dbase::adw_datid, ALLOCSET_DEFAULT_INITSIZE, ALLOCSET_DEFAULT_MAXSIZE, ALLOCSET_DEFAULT_MINSIZE, AllocSetContextCreate(), autovac_refresh_stats(), autovacuum_naptime, dlist_iter::cur, db_comparator(), dblist, dlist_container, dlist_foreach, dlist_init(), dlist_push_head(), HASHCTL::entrysize, get_database_list(), GetCurrentTimestamp(), HASHCTL::hash, HASH_CONTEXT, hash_create(), HASH_ELEM, HASH_ENTER, HASH_FUNCTION, hash_search(), hash_seq_init(), hash_seq_search(), HASHCTL::hcxt, i, HASHCTL::keysize, lfirst, MemoryContextDelete(), MemoryContextSwitchTo(), MIN_AUTOVAC_SLEEPTIME, NULL, OidIsValid, palloc(), pgstat_fetch_stat_dbentry(), qsort, and TimestampTzPlusMilliseconds.
Referenced by AutoVacLauncherMain(), do_start_worker(), launch_worker(), and launcher_determine_sleep().
{
List *dblist;
ListCell *cell;
MemoryContext newcxt;
MemoryContext oldcxt;
MemoryContext tmpcxt;
HASHCTL hctl;
int score;
int nelems;
HTAB *dbhash;
dlist_iter iter;
/* use fresh stats */
autovac_refresh_stats();
newcxt = AllocSetContextCreate(AutovacMemCxt,
"AV dblist",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
tmpcxt = AllocSetContextCreate(newcxt,
"tmp AV dblist",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
oldcxt = MemoryContextSwitchTo(tmpcxt);
/*
* Implementing this is not as simple as it sounds, because we need to put
* the new database at the end of the list; next the databases that were
* already on the list, and finally (at the tail of the list) all the
* other databases that are not on the existing list.
*
* To do this, we build an empty hash table of scored databases. We will
* start with the lowest score (zero) for the new database, then
* increasing scores for the databases in the existing list, in order, and
* lastly increasing scores for all databases gotten via
* get_database_list() that are not already on the hash.
*
* Then we will put all the hash elements into an array, sort the array by
* score, and finally put the array elements into the new doubly linked
* list.
*/
hctl.keysize = sizeof(Oid);
hctl.entrysize = sizeof(avl_dbase);
hctl.hash = oid_hash;
hctl.hcxt = tmpcxt;
dbhash = hash_create("db hash", 20, &hctl, /* magic number here FIXME */
HASH_ELEM | HASH_FUNCTION | HASH_CONTEXT);
/* start by inserting the new database */
score = 0;
if (OidIsValid(newdb))
{
avl_dbase *db;
PgStat_StatDBEntry *entry;
/* only consider this database if it has a pgstat entry */
entry = pgstat_fetch_stat_dbentry(newdb);
if (entry != NULL)
{
/* we assume it isn't found because the hash was just created */
db = hash_search(dbhash, &newdb, HASH_ENTER, NULL);
/* hash_search already filled in the key */
db->adl_score = score++;
/* next_worker is filled in later */
}
}
/* Now insert the databases from the existing list */
dlist_foreach(iter, &DatabaseList)
{
avl_dbase *avdb = dlist_container(avl_dbase, adl_node, iter.cur);
avl_dbase *db;
bool found;
PgStat_StatDBEntry *entry;
/*
* skip databases with no stat entries -- in particular, this gets
* rid of dropped databases
*/
entry = pgstat_fetch_stat_dbentry(avdb->adl_datid);
if (entry == NULL)
continue;
db = hash_search(dbhash, &(avdb->adl_datid), HASH_ENTER, &found);
if (!found)
{
/* hash_search already filled in the key */
db->adl_score = score++;
/* next_worker is filled in later */
}
}
/* finally, insert all qualifying databases not previously inserted */
dblist = get_database_list();
foreach(cell, dblist)
{
avw_dbase *avdb = lfirst(cell);
avl_dbase *db;
bool found;
PgStat_StatDBEntry *entry;
/* only consider databases with a pgstat entry */
entry = pgstat_fetch_stat_dbentry(avdb->adw_datid);
if (entry == NULL)
continue;
db = hash_search(dbhash, &(avdb->adw_datid), HASH_ENTER, &found);
/* only update the score if the database was not already on the hash */
if (!found)
{
/* hash_search already filled in the key */
db->adl_score = score++;
/* next_worker is filled in later */
}
}
nelems = score;
/* from here on, the allocated memory belongs to the new list */
MemoryContextSwitchTo(newcxt);
dlist_init(&DatabaseList);
if (nelems > 0)
{
TimestampTz current_time;
int millis_increment;
avl_dbase *dbary;
avl_dbase *db;
HASH_SEQ_STATUS seq;
int i;
/* put all the hash elements into an array */
dbary = palloc(nelems * sizeof(avl_dbase));
i = 0;
hash_seq_init(&seq, dbhash);
while ((db = hash_seq_search(&seq)) != NULL)
memcpy(&(dbary[i++]), db, sizeof(avl_dbase));
/* sort the array */
qsort(dbary, nelems, sizeof(avl_dbase), db_comparator);
/*
* Determine the time interval between databases in the schedule. If
* we see that the configured naptime would take us to sleep times
* lower than our min sleep time (which launcher_determine_sleep is
* coded not to allow), silently use a larger naptime (but don't touch
* the GUC variable).
*/
millis_increment = 1000.0 * autovacuum_naptime / nelems;
if (millis_increment <= MIN_AUTOVAC_SLEEPTIME)
millis_increment = MIN_AUTOVAC_SLEEPTIME * 1.1;
current_time = GetCurrentTimestamp();
/*
* move the elements from the array into the dllist, setting the
* next_worker while walking the array
*/
for (i = 0; i < nelems; i++)
{
avl_dbase *db = &(dbary[i]);
current_time = TimestampTzPlusMilliseconds(current_time,
millis_increment);
db->adl_next_worker = current_time;
/* later elements should go closer to the head of the list */
dlist_push_head(&DatabaseList, &db->adl_node);
}
}
/* all done, clean up memory */
if (DatabaseListCxt != NULL)
MemoryContextDelete(DatabaseListCxt);
MemoryContextDelete(tmpcxt);
DatabaseListCxt = newcxt;
MemoryContextSwitchTo(oldcxt);
}
| static void relation_needs_vacanalyze | ( | Oid | relid, | |
| AutoVacOpts * | relopts, | |||
| Form_pg_class | classForm, | |||
| PgStat_StatTabEntry * | tabentry, | |||
| bool * | dovacuum, | |||
| bool * | doanalyze, | |||
| bool * | wraparound | |||
| ) | [static] |
Definition at line 2604 of file autovacuum.c.
References AutoVacOpts::analyze_scale_factor, AutoVacOpts::analyze_threshold, AssertArg, autovacuum_anl_scale, autovacuum_anl_thresh, autovacuum_freeze_max_age, autovacuum_vac_scale, autovacuum_vac_thresh, PgStat_StatTabEntry::changes_since_analyze, DEBUG3, elog, AutoVacOpts::enabled, FirstMultiXactId, FirstNormalTransactionId, AutoVacOpts::freeze_max_age, Min, MultiXactIdPrecedes(), PgStat_StatTabEntry::n_dead_tuples, NameStr, NULL, OidIsValid, PointerIsValid, recentMulti, recentXid, StatisticRelationId, TransactionIdIsNormal, TransactionIdPrecedes(), AutoVacOpts::vacuum_scale_factor, and AutoVacOpts::vacuum_threshold.
Referenced by do_autovacuum(), and table_recheck_autovac().
{
bool force_vacuum;
bool av_enabled;
float4 reltuples; /* pg_class.reltuples */
/* constants from reloptions or GUC variables */
int vac_base_thresh,
anl_base_thresh;
float4 vac_scale_factor,
anl_scale_factor;
/* thresholds calculated from above constants */
float4 vacthresh,
anlthresh;
/* number of vacuum (resp. analyze) tuples at this time */
float4 vactuples,
anltuples;
/* freeze parameters */
int freeze_max_age;
TransactionId xidForceLimit;
MultiXactId multiForceLimit;
AssertArg(classForm != NULL);
AssertArg(OidIsValid(relid));
/*
* Determine vacuum/analyze equation parameters. We have two possible
* sources: the passed reloptions (which could be a main table or a toast
* table), or the autovacuum GUC variables.
*/
/* -1 in autovac setting means use plain vacuum_cost_delay */
vac_scale_factor = (relopts && relopts->vacuum_scale_factor >= 0)
? relopts->vacuum_scale_factor
: autovacuum_vac_scale;
vac_base_thresh = (relopts && relopts->vacuum_threshold >= 0)
? relopts->vacuum_threshold
: autovacuum_vac_thresh;
anl_scale_factor = (relopts && relopts->analyze_scale_factor >= 0)
? relopts->analyze_scale_factor
: autovacuum_anl_scale;
anl_base_thresh = (relopts && relopts->analyze_threshold >= 0)
? relopts->analyze_threshold
: autovacuum_anl_thresh;
freeze_max_age = (relopts && relopts->freeze_max_age >= 0)
? Min(relopts->freeze_max_age, autovacuum_freeze_max_age)
: autovacuum_freeze_max_age;
av_enabled = (relopts ? relopts->enabled : true);
/* Force vacuum if table is at risk of wraparound */
xidForceLimit = recentXid - freeze_max_age;
if (xidForceLimit < FirstNormalTransactionId)
xidForceLimit -= FirstNormalTransactionId;
force_vacuum = (TransactionIdIsNormal(classForm->relfrozenxid) &&
TransactionIdPrecedes(classForm->relfrozenxid,
xidForceLimit));
if (!force_vacuum)
{
multiForceLimit = recentMulti - autovacuum_freeze_max_age;
if (multiForceLimit < FirstMultiXactId)
multiForceLimit -= FirstMultiXactId;
force_vacuum = MultiXactIdPrecedes(classForm->relminmxid,
multiForceLimit);
}
*wraparound = force_vacuum;
/* User disabled it in pg_class.reloptions? (But ignore if at risk) */
if (!force_vacuum && !av_enabled)
{
*doanalyze = false;
*dovacuum = false;
return;
}
if (PointerIsValid(tabentry))
{
reltuples = classForm->reltuples;
vactuples = tabentry->n_dead_tuples;
anltuples = tabentry->changes_since_analyze;
vacthresh = (float4) vac_base_thresh + vac_scale_factor * reltuples;
anlthresh = (float4) anl_base_thresh + anl_scale_factor * reltuples;
/*
* Note that we don't need to take special consideration for stat
* reset, because if that happens, the last vacuum and analyze counts
* will be reset too.
*/
elog(DEBUG3, "%s: vac: %.0f (threshold %.0f), anl: %.0f (threshold %.0f)",
NameStr(classForm->relname),
vactuples, vacthresh, anltuples, anlthresh);
/* Determine if this table needs vacuum or analyze. */
*dovacuum = force_vacuum || (vactuples > vacthresh);
*doanalyze = (anltuples > anlthresh);
}
else
{
/*
* Skip a table not found in stat hash, unless we have to force vacuum
* for anti-wrap purposes. If it's not acted upon, there's no need to
* vacuum it.
*/
*dovacuum = force_vacuum;
*doanalyze = false;
}
/* ANALYZE refuses to work with pg_statistics */
if (relid == StatisticRelationId)
*doanalyze = false;
}
| int StartAutoVacLauncher | ( | void | ) |
Definition at line 360 of file autovacuum.c.
References AutoVacLauncherMain(), AutoVacPID, ClosePostmasterPorts(), ereport, errmsg(), fork_process(), LOG, NULL, and on_exit_reset().
Referenced by reaper(), and ServerLoop().
{
pid_t AutoVacPID;
#ifdef EXEC_BACKEND
switch ((AutoVacPID = avlauncher_forkexec()))
#else
switch ((AutoVacPID = fork_process()))
#endif
{
case -1:
ereport(LOG,
(errmsg("could not fork autovacuum launcher process: %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();
AutoVacLauncherMain(0, NULL);
break;
#endif
default:
return (int) AutoVacPID;
}
/* shouldn't get here */
return 0;
}
| int StartAutoVacWorker | ( | void | ) |
Definition at line 1435 of file autovacuum.c.
References AutoVacWorkerMain(), ClosePostmasterPorts(), ereport, errmsg(), fork_process(), LOG, NULL, and on_exit_reset().
Referenced by StartAutovacuumWorker().
{
pid_t worker_pid;
#ifdef EXEC_BACKEND
switch ((worker_pid = avworker_forkexec()))
#else
switch ((worker_pid = fork_process()))
#endif
{
case -1:
ereport(LOG,
(errmsg("could not fork autovacuum worker process: %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();
AutoVacWorkerMain(0, NULL);
break;
#endif
default:
return (int) worker_pid;
}
/* shouldn't get here */
return 0;
}
| static autovac_table * table_recheck_autovac | ( | Oid | relid, | |
| HTAB * | table_toast_map, | |||
| TupleDesc | pg_class_desc | |||
| ) | [static] |
Definition at line 2457 of file autovacuum.c.
References av_relation::ar_hasrelopts, av_relation::ar_reloptions, autovac_table::at_datname, autovac_table::at_doanalyze, autovac_table::at_dovacuum, autovac_table::at_freeze_min_age, autovac_table::at_freeze_table_age, autovac_table::at_nspname, autovac_table::at_relid, autovac_table::at_relname, autovac_table::at_vacuum_cost_delay, autovac_table::at_vacuum_cost_limit, autovac_table::at_wraparound, autovac_refresh_stats(), autovacuum_vac_cost_delay, autovacuum_vac_cost_limit, default_freeze_min_age, default_freeze_table_age, extract_autovac_opts(), AutoVacOpts::freeze_min_age, AutoVacOpts::freeze_table_age, get_pgstat_tabentry_relid(), GETSTRUCT, HASH_FIND, hash_search(), heap_freetuple(), HeapTupleIsValid, InvalidOid, MyDatabaseId, NULL, ObjectIdGetDatum, palloc(), pgstat_fetch_stat_dbentry(), relation_needs_vacanalyze(), RELKIND_TOASTVALUE, RELOID, SearchSysCacheCopy1, AutoVacOpts::vacuum_cost_delay, AutoVacOpts::vacuum_cost_limit, VacuumCostDelay, and VacuumCostLimit.
Referenced by do_autovacuum().
{
Form_pg_class classForm;
HeapTuple classTup;
bool dovacuum;
bool doanalyze;
autovac_table *tab = NULL;
PgStat_StatTabEntry *tabentry;
PgStat_StatDBEntry *shared;
PgStat_StatDBEntry *dbentry;
bool wraparound;
AutoVacOpts *avopts;
/* use fresh stats */
autovac_refresh_stats();
shared = pgstat_fetch_stat_dbentry(InvalidOid);
dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
/* fetch the relation's relcache entry */
classTup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(classTup))
return NULL;
classForm = (Form_pg_class) GETSTRUCT(classTup);
/*
* Get the applicable reloptions. If it is a TOAST table, try to get the
* main table reloptions if the toast table itself doesn't have.
*/
avopts = extract_autovac_opts(classTup, pg_class_desc);
if (classForm->relkind == RELKIND_TOASTVALUE &&
avopts == NULL && table_toast_map != NULL)
{
av_relation *hentry;
bool found;
hentry = hash_search(table_toast_map, &relid, HASH_FIND, &found);
if (found && hentry->ar_hasrelopts)
avopts = &hentry->ar_reloptions;
}
/* fetch the pgstat table entry */
tabentry = get_pgstat_tabentry_relid(relid, classForm->relisshared,
shared, dbentry);
relation_needs_vacanalyze(relid, avopts, classForm, tabentry,
&dovacuum, &doanalyze, &wraparound);
/* ignore ANALYZE for toast tables */
if (classForm->relkind == RELKIND_TOASTVALUE)
doanalyze = false;
/* OK, it needs something done */
if (doanalyze || dovacuum)
{
int freeze_min_age;
int freeze_table_age;
int vac_cost_limit;
int vac_cost_delay;
/*
* Calculate the vacuum cost parameters and the freeze ages. If there
* are options set in pg_class.reloptions, use them; in the case of a
* toast table, try the main table too. Otherwise use the GUC
* defaults, autovacuum's own first and plain vacuum second.
*/
/* -1 in autovac setting means use plain vacuum_cost_delay */
vac_cost_delay = (avopts && avopts->vacuum_cost_delay >= 0)
? avopts->vacuum_cost_delay
: (autovacuum_vac_cost_delay >= 0)
? autovacuum_vac_cost_delay
: VacuumCostDelay;
/* 0 or -1 in autovac setting means use plain vacuum_cost_limit */
vac_cost_limit = (avopts && avopts->vacuum_cost_limit > 0)
? avopts->vacuum_cost_limit
: (autovacuum_vac_cost_limit > 0)
? autovacuum_vac_cost_limit
: VacuumCostLimit;
/* these do not have autovacuum-specific settings */
freeze_min_age = (avopts && avopts->freeze_min_age >= 0)
? avopts->freeze_min_age
: default_freeze_min_age;
freeze_table_age = (avopts && avopts->freeze_table_age >= 0)
? avopts->freeze_table_age
: default_freeze_table_age;
tab = palloc(sizeof(autovac_table));
tab->at_relid = relid;
tab->at_dovacuum = dovacuum;
tab->at_doanalyze = doanalyze;
tab->at_freeze_min_age = freeze_min_age;
tab->at_freeze_table_age = freeze_table_age;
tab->at_vacuum_cost_limit = vac_cost_limit;
tab->at_vacuum_cost_delay = vac_cost_delay;
tab->at_wraparound = wraparound;
tab->at_relname = NULL;
tab->at_nspname = NULL;
tab->at_datname = NULL;
}
heap_freetuple(classTup);
return tab;
}
bool am_autovacuum_launcher = false [static] |
Definition at line 132 of file autovacuum.c.
Referenced by AutoVacLauncherMain(), and IsAutoVacuumLauncherProcess().
bool am_autovacuum_worker = false [static] |
Definition at line 133 of file autovacuum.c.
Referenced by AutoVacWorkerMain(), and IsAutoVacuumWorkerProcess().
MemoryContext AutovacMemCxt [static] |
Definition at line 149 of file autovacuum.c.
| double autovacuum_anl_scale |
Definition at line 117 of file autovacuum.c.
Referenced by relation_needs_vacanalyze().
Definition at line 116 of file autovacuum.c.
Referenced by relation_needs_vacanalyze().
Definition at line 118 of file autovacuum.c.
Referenced by do_start_worker(), relation_needs_vacanalyze(), SetTransactionIdLimit(), and vacuum_set_xid_limits().
Definition at line 112 of file autovacuum.c.
Referenced by AutoVacuumShmemInit(), AutoVacuumShmemSize(), check_maxconnections(), InitializeMaxBackends(), InitProcGlobal(), MaxLivePostmasterChildren(), and RegisterBackgroundWorker().
Definition at line 113 of file autovacuum.c.
Referenced by AutoVacLauncherMain(), do_start_worker(), launch_worker(), launcher_determine_sleep(), and rebuild_database_list().
| bool autovacuum_start_daemon = false |
Definition at line 111 of file autovacuum.c.
Referenced by autovac_init(), and AutoVacuumingActive().
Definition at line 120 of file autovacuum.c.
Referenced by autovac_balance_cost(), and table_recheck_autovac().
Definition at line 121 of file autovacuum.c.
Referenced by autovac_balance_cost(), and table_recheck_autovac().
| double autovacuum_vac_scale |
Definition at line 115 of file autovacuum.c.
Referenced by relation_needs_vacanalyze().
Definition at line 114 of file autovacuum.c.
Referenced by relation_needs_vacanalyze().
| int AutovacuumLauncherPid = 0 |
Definition at line 276 of file autovacuum.c.
Referenced by FreeWorkerInfo(), and ProcKill().
AutoVacuumShmemStruct* AutoVacuumShmem [static] |
Definition at line 263 of file autovacuum.c.
dlist_head DatabaseList = DLIST_STATIC_INIT(DatabaseList) [static] |
Definition at line 269 of file autovacuum.c.
MemoryContext DatabaseListCxt = NULL [static] |
Definition at line 270 of file autovacuum.c.
int default_freeze_min_age [static] |
Definition at line 145 of file autovacuum.c.
Referenced by do_autovacuum(), and table_recheck_autovac().
int default_freeze_table_age [static] |
Definition at line 146 of file autovacuum.c.
Referenced by do_autovacuum(), and table_recheck_autovac().
volatile sig_atomic_t got_SIGHUP = false [static] |
Definition at line 136 of file autovacuum.c.
Referenced by AutoVacLauncherMain(), and avl_sighup_handler().
volatile sig_atomic_t got_SIGTERM = false [static] |
Definition at line 138 of file autovacuum.c.
Referenced by AutoVacLauncherMain(), and avl_sigterm_handler().
volatile sig_atomic_t got_SIGUSR2 = false [static] |
Definition at line 137 of file autovacuum.c.
Referenced by AutoVacLauncherMain(), and avl_sigusr2_handler().
| int Log_autovacuum_min_duration = -1 |
Definition at line 123 of file autovacuum.c.
Referenced by analyze_rel(), do_analyze_rel(), lazy_vacuum_rel(), and vacuum_rel().
WorkerInfo MyWorkerInfo = NULL [static] |
Definition at line 273 of file autovacuum.c.
MultiXactId recentMulti [static] |
Definition at line 142 of file autovacuum.c.
Referenced by AutoVacWorkerMain(), do_start_worker(), and relation_needs_vacanalyze().
TransactionId recentXid [static] |
Definition at line 141 of file autovacuum.c.
Referenced by AutoVacWorkerMain(), do_start_worker(), and relation_needs_vacanalyze().
1.7.1