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autovacuum.c
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1 /*-------------------------------------------------------------------------
2  *
3  * autovacuum.c
4  *
5  * PostgreSQL Integrated Autovacuum Daemon
6  *
7  * The autovacuum system is structured in two different kinds of processes: the
8  * autovacuum launcher and the autovacuum worker. The launcher is an
9  * always-running process, started by the postmaster when the autovacuum GUC
10  * parameter is set. The launcher schedules autovacuum workers to be started
11  * when appropriate. The workers are the processes which execute the actual
12  * vacuuming; they connect to a database as determined in the launcher, and
13  * once connected they examine the catalogs to select the tables to vacuum.
14  *
15  * The autovacuum launcher cannot start the worker processes by itself,
16  * because doing so would cause robustness issues (namely, failure to shut
17  * them down on exceptional conditions, and also, since the launcher is
18  * connected to shared memory and is thus subject to corruption there, it is
19  * not as robust as the postmaster). So it leaves that task to the postmaster.
20  *
21  * There is an autovacuum shared memory area, where the launcher stores
22  * information about the database it wants vacuumed. When it wants a new
23  * worker to start, it sets a flag in shared memory and sends a signal to the
24  * postmaster. Then postmaster knows nothing more than it must start a worker;
25  * so it forks a new child, which turns into a worker. This new process
26  * connects to shared memory, and there it can inspect the information that the
27  * launcher has set up.
28  *
29  * If the fork() call fails in the postmaster, it sets a flag in the shared
30  * memory area, and sends a signal to the launcher. The launcher, upon
31  * noticing the flag, can try starting the worker again by resending the
32  * signal. Note that the failure can only be transient (fork failure due to
33  * high load, memory pressure, too many processes, etc); more permanent
34  * problems, like failure to connect to a database, are detected later in the
35  * worker and dealt with just by having the worker exit normally. The launcher
36  * will launch a new worker again later, per schedule.
37  *
38  * When the worker is done vacuuming it sends SIGUSR2 to the launcher. The
39  * launcher then wakes up and is able to launch another worker, if the schedule
40  * is so tight that a new worker is needed immediately. At this time the
41  * launcher can also balance the settings for the various remaining workers'
42  * cost-based vacuum delay feature.
43  *
44  * Note that there can be more than one worker in a database concurrently.
45  * They will store the table they are currently vacuuming in shared memory, so
46  * that other workers avoid being blocked waiting for the vacuum lock for that
47  * table. They will also reload the pgstats data just before vacuuming each
48  * table, to avoid vacuuming a table that was just finished being vacuumed by
49  * another worker and thus is no longer noted in shared memory. However,
50  * there is a window (caused by pgstat delay) on which a worker may choose a
51  * table that was already vacuumed; this is a bug in the current design.
52  *
53  * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
54  * Portions Copyright (c) 1994, Regents of the University of California
55  *
56  *
57  * IDENTIFICATION
58  * src/backend/postmaster/autovacuum.c
59  *
60  *-------------------------------------------------------------------------
61  */
62 #include "postgres.h"
63 
64 #include <signal.h>
65 #include <sys/time.h>
66 #include <unistd.h>
67 
68 #include "access/heapam.h"
69 #include "access/htup_details.h"
70 #include "access/multixact.h"
71 #include "access/reloptions.h"
72 #include "access/tableam.h"
73 #include "access/transam.h"
74 #include "access/xact.h"
75 #include "catalog/dependency.h"
76 #include "catalog/namespace.h"
77 #include "catalog/pg_database.h"
78 #include "commands/dbcommands.h"
79 #include "commands/vacuum.h"
80 #include "lib/ilist.h"
81 #include "libpq/pqsignal.h"
82 #include "miscadmin.h"
83 #include "nodes/makefuncs.h"
84 #include "pgstat.h"
85 #include "postmaster/autovacuum.h"
87 #include "postmaster/interrupt.h"
88 #include "postmaster/postmaster.h"
89 #include "storage/bufmgr.h"
90 #include "storage/ipc.h"
91 #include "storage/latch.h"
92 #include "storage/lmgr.h"
93 #include "storage/pmsignal.h"
94 #include "storage/proc.h"
95 #include "storage/procsignal.h"
96 #include "storage/sinvaladt.h"
97 #include "storage/smgr.h"
98 #include "tcop/tcopprot.h"
99 #include "utils/fmgroids.h"
100 #include "utils/fmgrprotos.h"
101 #include "utils/lsyscache.h"
102 #include "utils/memutils.h"
103 #include "utils/ps_status.h"
104 #include "utils/rel.h"
105 #include "utils/snapmgr.h"
106 #include "utils/syscache.h"
107 #include "utils/timeout.h"
108 #include "utils/timestamp.h"
109 
110 
111 /*
112  * GUC parameters
113  */
126 
129 
131 
132 /* how long to keep pgstat data in the launcher, in milliseconds */
133 #define STATS_READ_DELAY 1000
134 
135 /* the minimum allowed time between two awakenings of the launcher */
136 #define MIN_AUTOVAC_SLEEPTIME 100.0 /* milliseconds */
137 #define MAX_AUTOVAC_SLEEPTIME 300 /* seconds */
138 
139 /* Flags to tell if we are in an autovacuum process */
140 static bool am_autovacuum_launcher = false;
141 static bool am_autovacuum_worker = false;
142 
143 /* Flags set by signal handlers */
144 static volatile sig_atomic_t got_SIGUSR2 = false;
145 
146 /* Comparison points for determining whether freeze_max_age is exceeded */
149 
150 /* Default freeze ages to use for autovacuum (varies by database) */
155 
156 /* Memory context for long-lived data */
158 
159 /* struct to keep track of databases in launcher */
160 typedef struct avl_dbase
161 {
162  Oid adl_datid; /* hash key -- must be first */
166 } avl_dbase;
167 
168 /* struct to keep track of databases in worker */
169 typedef struct avw_dbase
170 {
172  char *adw_name;
176 } avw_dbase;
177 
178 /* struct to keep track of tables to vacuum and/or analyze, in 1st pass */
179 typedef struct av_relation
180 {
181  Oid ar_toastrelid; /* hash key - must be first */
184  AutoVacOpts ar_reloptions; /* copy of AutoVacOpts from the main table's
185  * reloptions, or NULL if none */
186 } av_relation;
187 
188 /* struct to keep track of tables to vacuum and/or analyze, after rechecking */
189 typedef struct autovac_table
190 {
197  char *at_relname;
198  char *at_nspname;
199  char *at_datname;
200 } autovac_table;
201 
202 /*-------------
203  * This struct holds information about a single worker's whereabouts. We keep
204  * an array of these in shared memory, sized according to
205  * autovacuum_max_workers.
206  *
207  * wi_links entry into free list or running list
208  * wi_dboid OID of the database this worker is supposed to work on
209  * wi_tableoid OID of the table currently being vacuumed, if any
210  * wi_sharedrel flag indicating whether table is marked relisshared
211  * wi_proc pointer to PGPROC of the running worker, NULL if not started
212  * wi_launchtime Time at which this worker was launched
213  * wi_cost_* Vacuum cost-based delay parameters current in this worker
214  *
215  * All fields are protected by AutovacuumLock, except for wi_tableoid and
216  * wi_sharedrel which are protected by AutovacuumScheduleLock (note these
217  * two fields are read-only for everyone except that worker itself).
218  *-------------
219  */
220 typedef struct WorkerInfoData
221 {
233 
234 typedef struct WorkerInfoData *WorkerInfo;
235 
236 /*
237  * Possible signals received by the launcher from remote processes. These are
238  * stored atomically in shared memory so that other processes can set them
239  * without locking.
240  */
241 typedef enum
242 {
243  AutoVacForkFailed, /* failed trying to start a worker */
244  AutoVacRebalance, /* rebalance the cost limits */
245  AutoVacNumSignals /* must be last */
247 
248 /*
249  * Autovacuum workitem array, stored in AutoVacuumShmem->av_workItems. This
250  * list is mostly protected by AutovacuumLock, except that if an item is
251  * marked 'active' other processes must not modify the work-identifying
252  * members.
253  */
254 typedef struct AutoVacuumWorkItem
255 {
257  bool avw_used; /* below data is valid */
258  bool avw_active; /* being processed */
263 
264 #define NUM_WORKITEMS 256
265 
266 /*-------------
267  * The main autovacuum shmem struct. On shared memory we store this main
268  * struct and the array of WorkerInfo structs. This struct keeps:
269  *
270  * av_signal set by other processes to indicate various conditions
271  * av_launcherpid the PID of the autovacuum launcher
272  * av_freeWorkers the WorkerInfo freelist
273  * av_runningWorkers the WorkerInfo non-free queue
274  * av_startingWorker pointer to WorkerInfo currently being started (cleared by
275  * the worker itself as soon as it's up and running)
276  * av_workItems work item array
277  *
278  * This struct is protected by AutovacuumLock, except for av_signal and parts
279  * of the worker list (see above).
280  *-------------
281  */
282 typedef struct
283 {
284  sig_atomic_t av_signal[AutoVacNumSignals];
288  WorkerInfo av_startingWorker;
291 
293 
294 /*
295  * the database list (of avl_dbase elements) in the launcher, and the context
296  * that contains it
297  */
300 
301 /* Pointer to my own WorkerInfo, valid on each worker */
302 static WorkerInfo MyWorkerInfo = NULL;
303 
304 /* PID of launcher, valid only in worker while shutting down */
306 
307 #ifdef EXEC_BACKEND
308 static pid_t avlauncher_forkexec(void);
309 static pid_t avworker_forkexec(void);
310 #endif
311 NON_EXEC_STATIC void AutoVacWorkerMain(int argc, char *argv[]) pg_attribute_noreturn();
312 NON_EXEC_STATIC void AutoVacLauncherMain(int argc, char *argv[]) pg_attribute_noreturn();
313 
314 static Oid do_start_worker(void);
315 static void HandleAutoVacLauncherInterrupts(void);
317 static void launcher_determine_sleep(bool canlaunch, bool recursing,
318  struct timeval *nap);
319 static void launch_worker(TimestampTz now);
320 static List *get_database_list(void);
321 static void rebuild_database_list(Oid newdb);
322 static int db_comparator(const void *a, const void *b);
323 static void autovac_balance_cost(void);
324 
325 static void do_autovacuum(void);
326 static void FreeWorkerInfo(int code, Datum arg);
327 
328 static autovac_table *table_recheck_autovac(Oid relid, HTAB *table_toast_map,
329  TupleDesc pg_class_desc,
330  int effective_multixact_freeze_max_age);
331 static void relation_needs_vacanalyze(Oid relid, AutoVacOpts *relopts,
332  Form_pg_class classForm,
333  PgStat_StatTabEntry *tabentry,
334  int effective_multixact_freeze_max_age,
335  bool *dovacuum, bool *doanalyze, bool *wraparound);
336 
338  BufferAccessStrategy bstrategy);
340  TupleDesc pg_class_desc);
341 static PgStat_StatTabEntry *get_pgstat_tabentry_relid(Oid relid, bool isshared,
342  PgStat_StatDBEntry *shared,
343  PgStat_StatDBEntry *dbentry);
344 static void perform_work_item(AutoVacuumWorkItem *workitem);
345 static void autovac_report_activity(autovac_table *tab);
346 static void autovac_report_workitem(AutoVacuumWorkItem *workitem,
347  const char *nspname, const char *relname);
348 static void avl_sigusr2_handler(SIGNAL_ARGS);
349 static void autovac_refresh_stats(void);
350 
351 
352 
353 /********************************************************************
354  * AUTOVACUUM LAUNCHER CODE
355  ********************************************************************/
356 
357 #ifdef EXEC_BACKEND
358 /*
359  * forkexec routine for the autovacuum launcher process.
360  *
361  * Format up the arglist, then fork and exec.
362  */
363 static pid_t
364 avlauncher_forkexec(void)
365 {
366  char *av[10];
367  int ac = 0;
368 
369  av[ac++] = "postgres";
370  av[ac++] = "--forkavlauncher";
371  av[ac++] = NULL; /* filled in by postmaster_forkexec */
372  av[ac] = NULL;
373 
374  Assert(ac < lengthof(av));
375 
376  return postmaster_forkexec(ac, av);
377 }
378 
379 /*
380  * We need this set from the outside, before InitProcess is called
381  */
382 void
383 AutovacuumLauncherIAm(void)
384 {
385  am_autovacuum_launcher = true;
386 }
387 #endif
388 
389 /*
390  * Main entry point for autovacuum launcher process, to be called from the
391  * postmaster.
392  */
393 int
395 {
396  pid_t AutoVacPID;
397 
398 #ifdef EXEC_BACKEND
399  switch ((AutoVacPID = avlauncher_forkexec()))
400 #else
401  switch ((AutoVacPID = fork_process()))
402 #endif
403  {
404  case -1:
405  ereport(LOG,
406  (errmsg("could not fork autovacuum launcher process: %m")));
407  return 0;
408 
409 #ifndef EXEC_BACKEND
410  case 0:
411  /* in postmaster child ... */
413 
414  /* Close the postmaster's sockets */
415  ClosePostmasterPorts(false);
416 
417  AutoVacLauncherMain(0, NULL);
418  break;
419 #endif
420  default:
421  return (int) AutoVacPID;
422  }
423 
424  /* shouldn't get here */
425  return 0;
426 }
427 
428 /*
429  * Main loop for the autovacuum launcher process.
430  */
431 NON_EXEC_STATIC void
432 AutoVacLauncherMain(int argc, char *argv[])
433 {
434  sigjmp_buf local_sigjmp_buf;
435 
436  am_autovacuum_launcher = true;
437 
439  init_ps_display(NULL);
440 
441  ereport(DEBUG1,
442  (errmsg("autovacuum launcher started")));
443 
444  if (PostAuthDelay)
445  pg_usleep(PostAuthDelay * 1000000L);
446 
448 
449  /*
450  * Set up signal handlers. We operate on databases much like a regular
451  * backend, so we use the same signal handling. See equivalent code in
452  * tcop/postgres.c.
453  */
457 
459  InitializeTimeouts(); /* establishes SIGALRM handler */
460 
466 
467  /* Early initialization */
468  BaseInit();
469 
470  /*
471  * Create a per-backend PGPROC struct in shared memory, except in the
472  * EXEC_BACKEND case where this was done in SubPostmasterMain. We must do
473  * this before we can use LWLocks (and in the EXEC_BACKEND case we already
474  * had to do some stuff with LWLocks).
475  */
476 #ifndef EXEC_BACKEND
477  InitProcess();
478 #endif
479 
480  InitPostgres(NULL, InvalidOid, NULL, InvalidOid, NULL, false);
481 
483 
484  /*
485  * Create a memory context that we will do all our work in. We do this so
486  * that we can reset the context during error recovery and thereby avoid
487  * possible memory leaks.
488  */
489  AutovacMemCxt = AllocSetContextCreate(TopMemoryContext,
490  "Autovacuum Launcher",
492  MemoryContextSwitchTo(AutovacMemCxt);
493 
494  /*
495  * If an exception is encountered, processing resumes here.
496  *
497  * This code is a stripped down version of PostgresMain error recovery.
498  */
499  if (sigsetjmp(local_sigjmp_buf, 1) != 0)
500  {
501  /* since not using PG_TRY, must reset error stack by hand */
502  error_context_stack = NULL;
503 
504  /* Prevents interrupts while cleaning up */
505  HOLD_INTERRUPTS();
506 
507  /* Forget any pending QueryCancel or timeout request */
508  disable_all_timeouts(false);
509  QueryCancelPending = false; /* second to avoid race condition */
510 
511  /* Report the error to the server log */
512  EmitErrorReport();
513 
514  /* Abort the current transaction in order to recover */
516 
517  /*
518  * Release any other resources, for the case where we were not in a
519  * transaction.
520  */
523  AbortBufferIO();
524  UnlockBuffers();
525  /* this is probably dead code, but let's be safe: */
528  AtEOXact_Buffers(false);
529  AtEOXact_SMgr();
530  AtEOXact_Files(false);
531  AtEOXact_HashTables(false);
532 
533  /*
534  * Now return to normal top-level context and clear ErrorContext for
535  * next time.
536  */
537  MemoryContextSwitchTo(AutovacMemCxt);
538  FlushErrorState();
539 
540  /* Flush any leaked data in the top-level context */
542 
543  /* don't leave dangling pointers to freed memory */
544  DatabaseListCxt = NULL;
545  dlist_init(&DatabaseList);
546 
547  /*
548  * Make sure pgstat also considers our stat data as gone. Note: we
549  * mustn't use autovac_refresh_stats here.
550  */
552 
553  /* Now we can allow interrupts again */
555 
556  /* if in shutdown mode, no need for anything further; just go away */
559 
560  /*
561  * Sleep at least 1 second after any error. We don't want to be
562  * filling the error logs as fast as we can.
563  */
564  pg_usleep(1000000L);
565  }
566 
567  /* We can now handle ereport(ERROR) */
568  PG_exception_stack = &local_sigjmp_buf;
569 
570  /* must unblock signals before calling rebuild_database_list */
572 
573  /*
574  * Set always-secure search path. Launcher doesn't connect to a database,
575  * so this has no effect.
576  */
577  SetConfigOption("search_path", "", PGC_SUSET, PGC_S_OVERRIDE);
578 
579  /*
580  * Force zero_damaged_pages OFF in the autovac process, even if it is set
581  * in postgresql.conf. We don't really want such a dangerous option being
582  * applied non-interactively.
583  */
584  SetConfigOption("zero_damaged_pages", "false", PGC_SUSET, PGC_S_OVERRIDE);
585 
586  /*
587  * Force settable timeouts off to avoid letting these settings prevent
588  * regular maintenance from being executed.
589  */
590  SetConfigOption("statement_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
591  SetConfigOption("lock_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
592  SetConfigOption("idle_in_transaction_session_timeout", "0",
594 
595  /*
596  * Force default_transaction_isolation to READ COMMITTED. We don't want
597  * to pay the overhead of serializable mode, nor add any risk of causing
598  * deadlocks or delaying other transactions.
599  */
600  SetConfigOption("default_transaction_isolation", "read committed",
602 
603  /*
604  * In emergency mode, just start a worker (unless shutdown was requested)
605  * and go away.
606  */
607  if (!AutoVacuumingActive())
608  {
610  do_start_worker();
611  proc_exit(0); /* done */
612  }
613 
614  AutoVacuumShmem->av_launcherpid = MyProcPid;
615 
616  /*
617  * Create the initial database list. The invariant we want this list to
618  * keep is that it's ordered by decreasing next_time. As soon as an entry
619  * is updated to a higher time, it will be moved to the front (which is
620  * correct because the only operation is to add autovacuum_naptime to the
621  * entry, and time always increases).
622  */
624 
625  /* loop until shutdown request */
626  while (!ShutdownRequestPending)
627  {
628  struct timeval nap;
629  TimestampTz current_time = 0;
630  bool can_launch;
631 
632  /*
633  * This loop is a bit different from the normal use of WaitLatch,
634  * because we'd like to sleep before the first launch of a child
635  * process. So it's WaitLatch, then ResetLatch, then check for
636  * wakening conditions.
637  */
638 
640  false, &nap);
641 
642  /*
643  * Wait until naptime expires or we get some type of signal (all the
644  * signal handlers will wake us by calling SetLatch).
645  */
646  (void) WaitLatch(MyLatch,
648  (nap.tv_sec * 1000L) + (nap.tv_usec / 1000L),
650 
652 
654 
655  /*
656  * a worker finished, or postmaster signalled failure to start a
657  * worker
658  */
659  if (got_SIGUSR2)
660  {
661  got_SIGUSR2 = false;
662 
663  /* rebalance cost limits, if needed */
664  if (AutoVacuumShmem->av_signal[AutoVacRebalance])
665  {
666  LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
667  AutoVacuumShmem->av_signal[AutoVacRebalance] = false;
669  LWLockRelease(AutovacuumLock);
670  }
671 
672  if (AutoVacuumShmem->av_signal[AutoVacForkFailed])
673  {
674  /*
675  * If the postmaster failed to start a new worker, we sleep
676  * for a little while and resend the signal. The new worker's
677  * state is still in memory, so this is sufficient. After
678  * that, we restart the main loop.
679  *
680  * XXX should we put a limit to the number of times we retry?
681  * I don't think it makes much sense, because a future start
682  * of a worker will continue to fail in the same way.
683  */
684  AutoVacuumShmem->av_signal[AutoVacForkFailed] = false;
685  pg_usleep(1000000L); /* 1s */
687  continue;
688  }
689  }
690 
691  /*
692  * There are some conditions that we need to check before trying to
693  * start a worker. First, we need to make sure that there is a worker
694  * slot available. Second, we need to make sure that no other worker
695  * failed while starting up.
696  */
697 
698  current_time = GetCurrentTimestamp();
699  LWLockAcquire(AutovacuumLock, LW_SHARED);
700 
701  can_launch = !dlist_is_empty(&AutoVacuumShmem->av_freeWorkers);
702 
703  if (AutoVacuumShmem->av_startingWorker != NULL)
704  {
705  int waittime;
706  WorkerInfo worker = AutoVacuumShmem->av_startingWorker;
707 
708  /*
709  * We can't launch another worker when another one is still
710  * starting up (or failed while doing so), so just sleep for a bit
711  * more; that worker will wake us up again as soon as it's ready.
712  * We will only wait autovacuum_naptime seconds (up to a maximum
713  * of 60 seconds) for this to happen however. Note that failure
714  * to connect to a particular database is not a problem here,
715  * because the worker removes itself from the startingWorker
716  * pointer before trying to connect. Problems detected by the
717  * postmaster (like fork() failure) are also reported and handled
718  * differently. The only problems that may cause this code to
719  * fire are errors in the earlier sections of AutoVacWorkerMain,
720  * before the worker removes the WorkerInfo from the
721  * startingWorker pointer.
722  */
723  waittime = Min(autovacuum_naptime, 60) * 1000;
724  if (TimestampDifferenceExceeds(worker->wi_launchtime, current_time,
725  waittime))
726  {
727  LWLockRelease(AutovacuumLock);
728  LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
729 
730  /*
731  * No other process can put a worker in starting mode, so if
732  * startingWorker is still INVALID after exchanging our lock,
733  * we assume it's the same one we saw above (so we don't
734  * recheck the launch time).
735  */
736  if (AutoVacuumShmem->av_startingWorker != NULL)
737  {
738  worker = AutoVacuumShmem->av_startingWorker;
739  worker->wi_dboid = InvalidOid;
740  worker->wi_tableoid = InvalidOid;
741  worker->wi_sharedrel = false;
742  worker->wi_proc = NULL;
743  worker->wi_launchtime = 0;
744  dlist_push_head(&AutoVacuumShmem->av_freeWorkers,
745  &worker->wi_links);
746  AutoVacuumShmem->av_startingWorker = NULL;
747  elog(WARNING, "worker took too long to start; canceled");
748  }
749  }
750  else
751  can_launch = false;
752  }
753  LWLockRelease(AutovacuumLock); /* either shared or exclusive */
754 
755  /* if we can't do anything, just go back to sleep */
756  if (!can_launch)
757  continue;
758 
759  /* We're OK to start a new worker */
760 
761  if (dlist_is_empty(&DatabaseList))
762  {
763  /*
764  * Special case when the list is empty: start a worker right away.
765  * This covers the initial case, when no database is in pgstats
766  * (thus the list is empty). Note that the constraints in
767  * launcher_determine_sleep keep us from starting workers too
768  * quickly (at most once every autovacuum_naptime when the list is
769  * empty).
770  */
771  launch_worker(current_time);
772  }
773  else
774  {
775  /*
776  * because rebuild_database_list constructs a list with most
777  * distant adl_next_worker first, we obtain our database from the
778  * tail of the list.
779  */
780  avl_dbase *avdb;
781 
782  avdb = dlist_tail_element(avl_dbase, adl_node, &DatabaseList);
783 
784  /*
785  * launch a worker if next_worker is right now or it is in the
786  * past
787  */
789  current_time, 0))
790  launch_worker(current_time);
791  }
792  }
793 
795 }
796 
797 /*
798  * Process any new interrupts.
799  */
800 static void
802 {
803  /* the normal shutdown case */
806 
808  {
809  ConfigReloadPending = false;
811 
812  /* shutdown requested in config file? */
813  if (!AutoVacuumingActive())
815 
816  /* rebalance in case the default cost parameters changed */
817  LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
819  LWLockRelease(AutovacuumLock);
820 
821  /* rebuild the list in case the naptime changed */
823  }
824 
825  /* Process barrier events */
828 
829  /* Process sinval catchup interrupts that happened while sleeping */
831 }
832 
833 /*
834  * Perform a normal exit from the autovac launcher.
835  */
836 static void
838 {
839  ereport(DEBUG1,
840  (errmsg("autovacuum launcher shutting down")));
841  AutoVacuumShmem->av_launcherpid = 0;
842 
843  proc_exit(0); /* done */
844 }
845 
846 /*
847  * Determine the time to sleep, based on the database list.
848  *
849  * The "canlaunch" parameter indicates whether we can start a worker right now,
850  * for example due to the workers being all busy. If this is false, we will
851  * cause a long sleep, which will be interrupted when a worker exits.
852  */
853 static void
854 launcher_determine_sleep(bool canlaunch, bool recursing, struct timeval *nap)
855 {
856  /*
857  * We sleep until the next scheduled vacuum. We trust that when the
858  * database list was built, care was taken so that no entries have times
859  * in the past; if the first entry has too close a next_worker value, or a
860  * time in the past, we will sleep a small nominal time.
861  */
862  if (!canlaunch)
863  {
864  nap->tv_sec = autovacuum_naptime;
865  nap->tv_usec = 0;
866  }
867  else if (!dlist_is_empty(&DatabaseList))
868  {
869  TimestampTz current_time = GetCurrentTimestamp();
870  TimestampTz next_wakeup;
871  avl_dbase *avdb;
872  long secs;
873  int usecs;
874 
875  avdb = dlist_tail_element(avl_dbase, adl_node, &DatabaseList);
876 
877  next_wakeup = avdb->adl_next_worker;
878  TimestampDifference(current_time, next_wakeup, &secs, &usecs);
879 
880  nap->tv_sec = secs;
881  nap->tv_usec = usecs;
882  }
883  else
884  {
885  /* list is empty, sleep for whole autovacuum_naptime seconds */
886  nap->tv_sec = autovacuum_naptime;
887  nap->tv_usec = 0;
888  }
889 
890  /*
891  * If the result is exactly zero, it means a database had an entry with
892  * time in the past. Rebuild the list so that the databases are evenly
893  * distributed again, and recalculate the time to sleep. This can happen
894  * if there are more tables needing vacuum than workers, and they all take
895  * longer to vacuum than autovacuum_naptime.
896  *
897  * We only recurse once. rebuild_database_list should always return times
898  * in the future, but it seems best not to trust too much on that.
899  */
900  if (nap->tv_sec == 0 && nap->tv_usec == 0 && !recursing)
901  {
903  launcher_determine_sleep(canlaunch, true, nap);
904  return;
905  }
906 
907  /* The smallest time we'll allow the launcher to sleep. */
908  if (nap->tv_sec <= 0 && nap->tv_usec <= MIN_AUTOVAC_SLEEPTIME * 1000)
909  {
910  nap->tv_sec = 0;
911  nap->tv_usec = MIN_AUTOVAC_SLEEPTIME * 1000;
912  }
913 
914  /*
915  * If the sleep time is too large, clamp it to an arbitrary maximum (plus
916  * any fractional seconds, for simplicity). This avoids an essentially
917  * infinite sleep in strange cases like the system clock going backwards a
918  * few years.
919  */
920  if (nap->tv_sec > MAX_AUTOVAC_SLEEPTIME)
921  nap->tv_sec = MAX_AUTOVAC_SLEEPTIME;
922 }
923 
924 /*
925  * Build an updated DatabaseList. It must only contain databases that appear
926  * in pgstats, and must be sorted by next_worker from highest to lowest,
927  * distributed regularly across the next autovacuum_naptime interval.
928  *
929  * Receives the Oid of the database that made this list be generated (we call
930  * this the "new" database, because when the database was already present on
931  * the list, we expect that this function is not called at all). The
932  * preexisting list, if any, will be used to preserve the order of the
933  * databases in the autovacuum_naptime period. The new database is put at the
934  * end of the interval. The actual values are not saved, which should not be
935  * much of a problem.
936  */
937 static void
939 {
940  List *dblist;
941  ListCell *cell;
942  MemoryContext newcxt;
943  MemoryContext oldcxt;
944  MemoryContext tmpcxt;
945  HASHCTL hctl;
946  int score;
947  int nelems;
948  HTAB *dbhash;
949  dlist_iter iter;
950 
951  /* use fresh stats */
953 
954  newcxt = AllocSetContextCreate(AutovacMemCxt,
955  "AV dblist",
957  tmpcxt = AllocSetContextCreate(newcxt,
958  "tmp AV dblist",
960  oldcxt = MemoryContextSwitchTo(tmpcxt);
961 
962  /*
963  * Implementing this is not as simple as it sounds, because we need to put
964  * the new database at the end of the list; next the databases that were
965  * already on the list, and finally (at the tail of the list) all the
966  * other databases that are not on the existing list.
967  *
968  * To do this, we build an empty hash table of scored databases. We will
969  * start with the lowest score (zero) for the new database, then
970  * increasing scores for the databases in the existing list, in order, and
971  * lastly increasing scores for all databases gotten via
972  * get_database_list() that are not already on the hash.
973  *
974  * Then we will put all the hash elements into an array, sort the array by
975  * score, and finally put the array elements into the new doubly linked
976  * list.
977  */
978  hctl.keysize = sizeof(Oid);
979  hctl.entrysize = sizeof(avl_dbase);
980  hctl.hcxt = tmpcxt;
981  dbhash = hash_create("db hash", 20, &hctl, /* magic number here FIXME */
983 
984  /* start by inserting the new database */
985  score = 0;
986  if (OidIsValid(newdb))
987  {
988  avl_dbase *db;
989  PgStat_StatDBEntry *entry;
990 
991  /* only consider this database if it has a pgstat entry */
992  entry = pgstat_fetch_stat_dbentry(newdb);
993  if (entry != NULL)
994  {
995  /* we assume it isn't found because the hash was just created */
996  db = hash_search(dbhash, &newdb, HASH_ENTER, NULL);
997 
998  /* hash_search already filled in the key */
999  db->adl_score = score++;
1000  /* next_worker is filled in later */
1001  }
1002  }
1003 
1004  /* Now insert the databases from the existing list */
1005  dlist_foreach(iter, &DatabaseList)
1006  {
1008  avl_dbase *db;
1009  bool found;
1010  PgStat_StatDBEntry *entry;
1011 
1012  /*
1013  * skip databases with no stat entries -- in particular, this gets rid
1014  * of dropped databases
1015  */
1016  entry = pgstat_fetch_stat_dbentry(avdb->adl_datid);
1017  if (entry == NULL)
1018  continue;
1019 
1020  db = hash_search(dbhash, &(avdb->adl_datid), HASH_ENTER, &found);
1021 
1022  if (!found)
1023  {
1024  /* hash_search already filled in the key */
1025  db->adl_score = score++;
1026  /* next_worker is filled in later */
1027  }
1028  }
1029 
1030  /* finally, insert all qualifying databases not previously inserted */
1031  dblist = get_database_list();
1032  foreach(cell, dblist)
1033  {
1034  avw_dbase *avdb = lfirst(cell);
1035  avl_dbase *db;
1036  bool found;
1037  PgStat_StatDBEntry *entry;
1038 
1039  /* only consider databases with a pgstat entry */
1040  entry = pgstat_fetch_stat_dbentry(avdb->adw_datid);
1041  if (entry == NULL)
1042  continue;
1043 
1044  db = hash_search(dbhash, &(avdb->adw_datid), HASH_ENTER, &found);
1045  /* only update the score if the database was not already on the hash */
1046  if (!found)
1047  {
1048  /* hash_search already filled in the key */
1049  db->adl_score = score++;
1050  /* next_worker is filled in later */
1051  }
1052  }
1053  nelems = score;
1054 
1055  /* from here on, the allocated memory belongs to the new list */
1056  MemoryContextSwitchTo(newcxt);
1057  dlist_init(&DatabaseList);
1058 
1059  if (nelems > 0)
1060  {
1061  TimestampTz current_time;
1062  int millis_increment;
1063  avl_dbase *dbary;
1064  avl_dbase *db;
1065  HASH_SEQ_STATUS seq;
1066  int i;
1067 
1068  /* put all the hash elements into an array */
1069  dbary = palloc(nelems * sizeof(avl_dbase));
1070 
1071  i = 0;
1072  hash_seq_init(&seq, dbhash);
1073  while ((db = hash_seq_search(&seq)) != NULL)
1074  memcpy(&(dbary[i++]), db, sizeof(avl_dbase));
1075 
1076  /* sort the array */
1077  qsort(dbary, nelems, sizeof(avl_dbase), db_comparator);
1078 
1079  /*
1080  * Determine the time interval between databases in the schedule. If
1081  * we see that the configured naptime would take us to sleep times
1082  * lower than our min sleep time (which launcher_determine_sleep is
1083  * coded not to allow), silently use a larger naptime (but don't touch
1084  * the GUC variable).
1085  */
1086  millis_increment = 1000.0 * autovacuum_naptime / nelems;
1087  if (millis_increment <= MIN_AUTOVAC_SLEEPTIME)
1088  millis_increment = MIN_AUTOVAC_SLEEPTIME * 1.1;
1089 
1090  current_time = GetCurrentTimestamp();
1091 
1092  /*
1093  * move the elements from the array into the dlist, setting the
1094  * next_worker while walking the array
1095  */
1096  for (i = 0; i < nelems; i++)
1097  {
1098  avl_dbase *db = &(dbary[i]);
1099 
1100  current_time = TimestampTzPlusMilliseconds(current_time,
1101  millis_increment);
1102  db->adl_next_worker = current_time;
1103 
1104  /* later elements should go closer to the head of the list */
1105  dlist_push_head(&DatabaseList, &db->adl_node);
1106  }
1107  }
1108 
1109  /* all done, clean up memory */
1110  if (DatabaseListCxt != NULL)
1111  MemoryContextDelete(DatabaseListCxt);
1112  MemoryContextDelete(tmpcxt);
1113  DatabaseListCxt = newcxt;
1114  MemoryContextSwitchTo(oldcxt);
1115 }
1116 
1117 /* qsort comparator for avl_dbase, using adl_score */
1118 static int
1119 db_comparator(const void *a, const void *b)
1120 {
1121  if (((const avl_dbase *) a)->adl_score == ((const avl_dbase *) b)->adl_score)
1122  return 0;
1123  else
1124  return (((const avl_dbase *) a)->adl_score < ((const avl_dbase *) b)->adl_score) ? 1 : -1;
1125 }
1126 
1127 /*
1128  * do_start_worker
1129  *
1130  * Bare-bones procedure for starting an autovacuum worker from the launcher.
1131  * It determines what database to work on, sets up shared memory stuff and
1132  * signals postmaster to start the worker. It fails gracefully if invoked when
1133  * autovacuum_workers are already active.
1134  *
1135  * Return value is the OID of the database that the worker is going to process,
1136  * or InvalidOid if no worker was actually started.
1137  */
1138 static Oid
1140 {
1141  List *dblist;
1142  ListCell *cell;
1143  TransactionId xidForceLimit;
1144  MultiXactId multiForceLimit;
1145  bool for_xid_wrap;
1146  bool for_multi_wrap;
1147  avw_dbase *avdb;
1148  TimestampTz current_time;
1149  bool skipit = false;
1150  Oid retval = InvalidOid;
1151  MemoryContext tmpcxt,
1152  oldcxt;
1153 
1154  /* return quickly when there are no free workers */
1155  LWLockAcquire(AutovacuumLock, LW_SHARED);
1156  if (dlist_is_empty(&AutoVacuumShmem->av_freeWorkers))
1157  {
1158  LWLockRelease(AutovacuumLock);
1159  return InvalidOid;
1160  }
1161  LWLockRelease(AutovacuumLock);
1162 
1163  /*
1164  * Create and switch to a temporary context to avoid leaking the memory
1165  * allocated for the database list.
1166  */
1168  "Start worker tmp cxt",
1170  oldcxt = MemoryContextSwitchTo(tmpcxt);
1171 
1172  /* use fresh stats */
1174 
1175  /* Get a list of databases */
1176  dblist = get_database_list();
1177 
1178  /*
1179  * Determine the oldest datfrozenxid/relfrozenxid that we will allow to
1180  * pass without forcing a vacuum. (This limit can be tightened for
1181  * particular tables, but not loosened.)
1182  */
1184  xidForceLimit = recentXid - autovacuum_freeze_max_age;
1185  /* ensure it's a "normal" XID, else TransactionIdPrecedes misbehaves */
1186  /* this can cause the limit to go backwards by 3, but that's OK */
1187  if (xidForceLimit < FirstNormalTransactionId)
1188  xidForceLimit -= FirstNormalTransactionId;
1189 
1190  /* Also determine the oldest datminmxid we will consider. */
1192  multiForceLimit = recentMulti - MultiXactMemberFreezeThreshold();
1193  if (multiForceLimit < FirstMultiXactId)
1194  multiForceLimit -= FirstMultiXactId;
1195 
1196  /*
1197  * Choose a database to connect to. We pick the database that was least
1198  * recently auto-vacuumed, or one that needs vacuuming to prevent Xid
1199  * wraparound-related data loss. If any db at risk of Xid wraparound is
1200  * found, we pick the one with oldest datfrozenxid, independently of
1201  * autovacuum times; similarly we pick the one with the oldest datminmxid
1202  * if any is in MultiXactId wraparound. Note that those in Xid wraparound
1203  * danger are given more priority than those in multi wraparound danger.
1204  *
1205  * Note that a database with no stats entry is not considered, except for
1206  * Xid wraparound purposes. The theory is that if no one has ever
1207  * connected to it since the stats were last initialized, it doesn't need
1208  * vacuuming.
1209  *
1210  * XXX This could be improved if we had more info about whether it needs
1211  * vacuuming before connecting to it. Perhaps look through the pgstats
1212  * data for the database's tables? One idea is to keep track of the
1213  * number of new and dead tuples per database in pgstats. However it
1214  * isn't clear how to construct a metric that measures that and not cause
1215  * starvation for less busy databases.
1216  */
1217  avdb = NULL;
1218  for_xid_wrap = false;
1219  for_multi_wrap = false;
1220  current_time = GetCurrentTimestamp();
1221  foreach(cell, dblist)
1222  {
1223  avw_dbase *tmp = lfirst(cell);
1224  dlist_iter iter;
1225 
1226  /* Check to see if this one is at risk of wraparound */
1227  if (TransactionIdPrecedes(tmp->adw_frozenxid, xidForceLimit))
1228  {
1229  if (avdb == NULL ||
1231  avdb->adw_frozenxid))
1232  avdb = tmp;
1233  for_xid_wrap = true;
1234  continue;
1235  }
1236  else if (for_xid_wrap)
1237  continue; /* ignore not-at-risk DBs */
1238  else if (MultiXactIdPrecedes(tmp->adw_minmulti, multiForceLimit))
1239  {
1240  if (avdb == NULL ||
1242  avdb = tmp;
1243  for_multi_wrap = true;
1244  continue;
1245  }
1246  else if (for_multi_wrap)
1247  continue; /* ignore not-at-risk DBs */
1248 
1249  /* Find pgstat entry if any */
1251 
1252  /*
1253  * Skip a database with no pgstat entry; it means it hasn't seen any
1254  * activity.
1255  */
1256  if (!tmp->adw_entry)
1257  continue;
1258 
1259  /*
1260  * Also, skip a database that appears on the database list as having
1261  * been processed recently (less than autovacuum_naptime seconds ago).
1262  * We do this so that we don't select a database which we just
1263  * selected, but that pgstat hasn't gotten around to updating the last
1264  * autovacuum time yet.
1265  */
1266  skipit = false;
1267 
1268  dlist_reverse_foreach(iter, &DatabaseList)
1269  {
1271 
1272  if (dbp->adl_datid == tmp->adw_datid)
1273  {
1274  /*
1275  * Skip this database if its next_worker value falls between
1276  * the current time and the current time plus naptime.
1277  */
1279  current_time, 0) &&
1280  !TimestampDifferenceExceeds(current_time,
1281  dbp->adl_next_worker,
1282  autovacuum_naptime * 1000))
1283  skipit = true;
1284 
1285  break;
1286  }
1287  }
1288  if (skipit)
1289  continue;
1290 
1291  /*
1292  * Remember the db with oldest autovac time. (If we are here, both
1293  * tmp->entry and db->entry must be non-null.)
1294  */
1295  if (avdb == NULL ||
1297  avdb = tmp;
1298  }
1299 
1300  /* Found a database -- process it */
1301  if (avdb != NULL)
1302  {
1303  WorkerInfo worker;
1304  dlist_node *wptr;
1305 
1306  LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
1307 
1308  /*
1309  * Get a worker entry from the freelist. We checked above, so there
1310  * really should be a free slot.
1311  */
1312  wptr = dlist_pop_head_node(&AutoVacuumShmem->av_freeWorkers);
1313 
1314  worker = dlist_container(WorkerInfoData, wi_links, wptr);
1315  worker->wi_dboid = avdb->adw_datid;
1316  worker->wi_proc = NULL;
1317  worker->wi_launchtime = GetCurrentTimestamp();
1318 
1319  AutoVacuumShmem->av_startingWorker = worker;
1320 
1321  LWLockRelease(AutovacuumLock);
1322 
1324 
1325  retval = avdb->adw_datid;
1326  }
1327  else if (skipit)
1328  {
1329  /*
1330  * If we skipped all databases on the list, rebuild it, because it
1331  * probably contains a dropped database.
1332  */
1334  }
1335 
1336  MemoryContextSwitchTo(oldcxt);
1337  MemoryContextDelete(tmpcxt);
1338 
1339  return retval;
1340 }
1341 
1342 /*
1343  * launch_worker
1344  *
1345  * Wrapper for starting a worker from the launcher. Besides actually starting
1346  * it, update the database list to reflect the next time that another one will
1347  * need to be started on the selected database. The actual database choice is
1348  * left to do_start_worker.
1349  *
1350  * This routine is also expected to insert an entry into the database list if
1351  * the selected database was previously absent from the list.
1352  */
1353 static void
1355 {
1356  Oid dbid;
1357  dlist_iter iter;
1358 
1359  dbid = do_start_worker();
1360  if (OidIsValid(dbid))
1361  {
1362  bool found = false;
1363 
1364  /*
1365  * Walk the database list and update the corresponding entry. If the
1366  * database is not on the list, we'll recreate the list.
1367  */
1368  dlist_foreach(iter, &DatabaseList)
1369  {
1371 
1372  if (avdb->adl_datid == dbid)
1373  {
1374  found = true;
1375 
1376  /*
1377  * add autovacuum_naptime seconds to the current time, and use
1378  * that as the new "next_worker" field for this database.
1379  */
1380  avdb->adl_next_worker =
1382 
1383  dlist_move_head(&DatabaseList, iter.cur);
1384  break;
1385  }
1386  }
1387 
1388  /*
1389  * If the database was not present in the database list, we rebuild
1390  * the list. It's possible that the database does not get into the
1391  * list anyway, for example if it's a database that doesn't have a
1392  * pgstat entry, but this is not a problem because we don't want to
1393  * schedule workers regularly into those in any case.
1394  */
1395  if (!found)
1396  rebuild_database_list(dbid);
1397  }
1398 }
1399 
1400 /*
1401  * Called from postmaster to signal a failure to fork a process to become
1402  * worker. The postmaster should kill(SIGUSR2) the launcher shortly
1403  * after calling this function.
1404  */
1405 void
1407 {
1408  AutoVacuumShmem->av_signal[AutoVacForkFailed] = true;
1409 }
1410 
1411 /* SIGUSR2: a worker is up and running, or just finished, or failed to fork */
1412 static void
1414 {
1415  int save_errno = errno;
1416 
1417  got_SIGUSR2 = true;
1418  SetLatch(MyLatch);
1419 
1420  errno = save_errno;
1421 }
1422 
1423 
1424 /********************************************************************
1425  * AUTOVACUUM WORKER CODE
1426  ********************************************************************/
1427 
1428 #ifdef EXEC_BACKEND
1429 /*
1430  * forkexec routines for the autovacuum worker.
1431  *
1432  * Format up the arglist, then fork and exec.
1433  */
1434 static pid_t
1435 avworker_forkexec(void)
1436 {
1437  char *av[10];
1438  int ac = 0;
1439 
1440  av[ac++] = "postgres";
1441  av[ac++] = "--forkavworker";
1442  av[ac++] = NULL; /* filled in by postmaster_forkexec */
1443  av[ac] = NULL;
1444 
1445  Assert(ac < lengthof(av));
1446 
1447  return postmaster_forkexec(ac, av);
1448 }
1449 
1450 /*
1451  * We need this set from the outside, before InitProcess is called
1452  */
1453 void
1454 AutovacuumWorkerIAm(void)
1455 {
1456  am_autovacuum_worker = true;
1457 }
1458 #endif
1459 
1460 /*
1461  * Main entry point for autovacuum worker process.
1462  *
1463  * This code is heavily based on pgarch.c, q.v.
1464  */
1465 int
1467 {
1468  pid_t worker_pid;
1469 
1470 #ifdef EXEC_BACKEND
1471  switch ((worker_pid = avworker_forkexec()))
1472 #else
1473  switch ((worker_pid = fork_process()))
1474 #endif
1475  {
1476  case -1:
1477  ereport(LOG,
1478  (errmsg("could not fork autovacuum worker process: %m")));
1479  return 0;
1480 
1481 #ifndef EXEC_BACKEND
1482  case 0:
1483  /* in postmaster child ... */
1485 
1486  /* Close the postmaster's sockets */
1487  ClosePostmasterPorts(false);
1488 
1489  AutoVacWorkerMain(0, NULL);
1490  break;
1491 #endif
1492  default:
1493  return (int) worker_pid;
1494  }
1495 
1496  /* shouldn't get here */
1497  return 0;
1498 }
1499 
1500 /*
1501  * AutoVacWorkerMain
1502  */
1503 NON_EXEC_STATIC void
1504 AutoVacWorkerMain(int argc, char *argv[])
1505 {
1506  sigjmp_buf local_sigjmp_buf;
1507  Oid dbid;
1508 
1509  am_autovacuum_worker = true;
1510 
1512  init_ps_display(NULL);
1513 
1515 
1516  /*
1517  * Set up signal handlers. We operate on databases much like a regular
1518  * backend, so we use the same signal handling. See equivalent code in
1519  * tcop/postgres.c.
1520  */
1522 
1523  /*
1524  * SIGINT is used to signal canceling the current table's vacuum; SIGTERM
1525  * means abort and exit cleanly, and SIGQUIT means abandon ship.
1526  */
1528  pqsignal(SIGTERM, die);
1530  InitializeTimeouts(); /* establishes SIGALRM handler */
1531 
1537 
1538  /* Early initialization */
1539  BaseInit();
1540 
1541  /*
1542  * Create a per-backend PGPROC struct in shared memory, except in the
1543  * EXEC_BACKEND case where this was done in SubPostmasterMain. We must do
1544  * this before we can use LWLocks (and in the EXEC_BACKEND case we already
1545  * had to do some stuff with LWLocks).
1546  */
1547 #ifndef EXEC_BACKEND
1548  InitProcess();
1549 #endif
1550 
1551  /*
1552  * If an exception is encountered, processing resumes here.
1553  *
1554  * See notes in postgres.c about the design of this coding.
1555  */
1556  if (sigsetjmp(local_sigjmp_buf, 1) != 0)
1557  {
1558  /* since not using PG_TRY, must reset error stack by hand */
1559  error_context_stack = NULL;
1560 
1561  /* Prevents interrupts while cleaning up */
1562  HOLD_INTERRUPTS();
1563 
1564  /* Report the error to the server log */
1565  EmitErrorReport();
1566 
1567  /*
1568  * We can now go away. Note that because we called InitProcess, a
1569  * callback was registered to do ProcKill, which will clean up
1570  * necessary state.
1571  */
1572  proc_exit(0);
1573  }
1574 
1575  /* We can now handle ereport(ERROR) */
1576  PG_exception_stack = &local_sigjmp_buf;
1577 
1579 
1580  /*
1581  * Set always-secure search path, so malicious users can't redirect user
1582  * code (e.g. pg_index.indexprs). (That code runs in a
1583  * SECURITY_RESTRICTED_OPERATION sandbox, so malicious users could not
1584  * take control of the entire autovacuum worker in any case.)
1585  */
1586  SetConfigOption("search_path", "", PGC_SUSET, PGC_S_OVERRIDE);
1587 
1588  /*
1589  * Force zero_damaged_pages OFF in the autovac process, even if it is set
1590  * in postgresql.conf. We don't really want such a dangerous option being
1591  * applied non-interactively.
1592  */
1593  SetConfigOption("zero_damaged_pages", "false", PGC_SUSET, PGC_S_OVERRIDE);
1594 
1595  /*
1596  * Force settable timeouts off to avoid letting these settings prevent
1597  * regular maintenance from being executed.
1598  */
1599  SetConfigOption("statement_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
1600  SetConfigOption("lock_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
1601  SetConfigOption("idle_in_transaction_session_timeout", "0",
1603 
1604  /*
1605  * Force default_transaction_isolation to READ COMMITTED. We don't want
1606  * to pay the overhead of serializable mode, nor add any risk of causing
1607  * deadlocks or delaying other transactions.
1608  */
1609  SetConfigOption("default_transaction_isolation", "read committed",
1611 
1612  /*
1613  * Force synchronous replication off to allow regular maintenance even if
1614  * we are waiting for standbys to connect. This is important to ensure we
1615  * aren't blocked from performing anti-wraparound tasks.
1616  */
1618  SetConfigOption("synchronous_commit", "local",
1620 
1621  /*
1622  * Get the info about the database we're going to work on.
1623  */
1624  LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
1625 
1626  /*
1627  * beware of startingWorker being INVALID; this should normally not
1628  * happen, but if a worker fails after forking and before this, the
1629  * launcher might have decided to remove it from the queue and start
1630  * again.
1631  */
1632  if (AutoVacuumShmem->av_startingWorker != NULL)
1633  {
1634  MyWorkerInfo = AutoVacuumShmem->av_startingWorker;
1635  dbid = MyWorkerInfo->wi_dboid;
1636  MyWorkerInfo->wi_proc = MyProc;
1637 
1638  /* insert into the running list */
1639  dlist_push_head(&AutoVacuumShmem->av_runningWorkers,
1640  &MyWorkerInfo->wi_links);
1641 
1642  /*
1643  * remove from the "starting" pointer, so that the launcher can start
1644  * a new worker if required
1645  */
1646  AutoVacuumShmem->av_startingWorker = NULL;
1647  LWLockRelease(AutovacuumLock);
1648 
1650 
1651  /* wake up the launcher */
1652  if (AutoVacuumShmem->av_launcherpid != 0)
1653  kill(AutoVacuumShmem->av_launcherpid, SIGUSR2);
1654  }
1655  else
1656  {
1657  /* no worker entry for me, go away */
1658  elog(WARNING, "autovacuum worker started without a worker entry");
1659  dbid = InvalidOid;
1660  LWLockRelease(AutovacuumLock);
1661  }
1662 
1663  if (OidIsValid(dbid))
1664  {
1665  char dbname[NAMEDATALEN];
1666 
1667  /*
1668  * Report autovac startup to the stats collector. We deliberately do
1669  * this before InitPostgres, so that the last_autovac_time will get
1670  * updated even if the connection attempt fails. This is to prevent
1671  * autovac from getting "stuck" repeatedly selecting an unopenable
1672  * database, rather than making any progress on stuff it can connect
1673  * to.
1674  */
1675  pgstat_report_autovac(dbid);
1676 
1677  /*
1678  * Connect to the selected database
1679  *
1680  * Note: if we have selected a just-deleted database (due to using
1681  * stale stats info), we'll fail and exit here.
1682  */
1683  InitPostgres(NULL, dbid, NULL, InvalidOid, dbname, false);
1685  set_ps_display(dbname);
1686  ereport(DEBUG1,
1687  (errmsg("autovacuum: processing database \"%s\"", dbname)));
1688 
1689  if (PostAuthDelay)
1690  pg_usleep(PostAuthDelay * 1000000L);
1691 
1692  /* And do an appropriate amount of work */
1695  do_autovacuum();
1696  }
1697 
1698  /*
1699  * The launcher will be notified of my death in ProcKill, *if* we managed
1700  * to get a worker slot at all
1701  */
1702 
1703  /* All done, go away */
1704  proc_exit(0);
1705 }
1706 
1707 /*
1708  * Return a WorkerInfo to the free list
1709  */
1710 static void
1712 {
1713  if (MyWorkerInfo != NULL)
1714  {
1715  LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
1716 
1717  /*
1718  * Wake the launcher up so that he can launch a new worker immediately
1719  * if required. We only save the launcher's PID in local memory here;
1720  * the actual signal will be sent when the PGPROC is recycled. Note
1721  * that we always do this, so that the launcher can rebalance the cost
1722  * limit setting of the remaining workers.
1723  *
1724  * We somewhat ignore the risk that the launcher changes its PID
1725  * between us reading it and the actual kill; we expect ProcKill to be
1726  * called shortly after us, and we assume that PIDs are not reused too
1727  * quickly after a process exits.
1728  */
1729  AutovacuumLauncherPid = AutoVacuumShmem->av_launcherpid;
1730 
1731  dlist_delete(&MyWorkerInfo->wi_links);
1732  MyWorkerInfo->wi_dboid = InvalidOid;
1733  MyWorkerInfo->wi_tableoid = InvalidOid;
1734  MyWorkerInfo->wi_sharedrel = false;
1735  MyWorkerInfo->wi_proc = NULL;
1736  MyWorkerInfo->wi_launchtime = 0;
1737  MyWorkerInfo->wi_dobalance = false;
1738  MyWorkerInfo->wi_cost_delay = 0;
1739  MyWorkerInfo->wi_cost_limit = 0;
1740  MyWorkerInfo->wi_cost_limit_base = 0;
1741  dlist_push_head(&AutoVacuumShmem->av_freeWorkers,
1742  &MyWorkerInfo->wi_links);
1743  /* not mine anymore */
1744  MyWorkerInfo = NULL;
1745 
1746  /*
1747  * now that we're inactive, cause a rebalancing of the surviving
1748  * workers
1749  */
1750  AutoVacuumShmem->av_signal[AutoVacRebalance] = true;
1751  LWLockRelease(AutovacuumLock);
1752  }
1753 }
1754 
1755 /*
1756  * Update the cost-based delay parameters, so that multiple workers consume
1757  * each a fraction of the total available I/O.
1758  */
1759 void
1761 {
1762  if (MyWorkerInfo)
1763  {
1764  VacuumCostDelay = MyWorkerInfo->wi_cost_delay;
1765  VacuumCostLimit = MyWorkerInfo->wi_cost_limit;
1766  }
1767 }
1768 
1769 /*
1770  * autovac_balance_cost
1771  * Recalculate the cost limit setting for each active worker.
1772  *
1773  * Caller must hold the AutovacuumLock in exclusive mode.
1774  */
1775 static void
1777 {
1778  /*
1779  * The idea here is that we ration out I/O equally. The amount of I/O
1780  * that a worker can consume is determined by cost_limit/cost_delay, so we
1781  * try to equalize those ratios rather than the raw limit settings.
1782  *
1783  * note: in cost_limit, zero also means use value from elsewhere, because
1784  * zero is not a valid value.
1785  */
1786  int vac_cost_limit = (autovacuum_vac_cost_limit > 0 ?
1788  double vac_cost_delay = (autovacuum_vac_cost_delay >= 0 ?
1790  double cost_total;
1791  double cost_avail;
1792  dlist_iter iter;
1793 
1794  /* not set? nothing to do */
1795  if (vac_cost_limit <= 0 || vac_cost_delay <= 0)
1796  return;
1797 
1798  /* calculate the total base cost limit of participating active workers */
1799  cost_total = 0.0;
1800  dlist_foreach(iter, &AutoVacuumShmem->av_runningWorkers)
1801  {
1802  WorkerInfo worker = dlist_container(WorkerInfoData, wi_links, iter.cur);
1803 
1804  if (worker->wi_proc != NULL &&
1805  worker->wi_dobalance &&
1806  worker->wi_cost_limit_base > 0 && worker->wi_cost_delay > 0)
1807  cost_total +=
1808  (double) worker->wi_cost_limit_base / worker->wi_cost_delay;
1809  }
1810 
1811  /* there are no cost limits -- nothing to do */
1812  if (cost_total <= 0)
1813  return;
1814 
1815  /*
1816  * Adjust cost limit of each active worker to balance the total of cost
1817  * limit to autovacuum_vacuum_cost_limit.
1818  */
1819  cost_avail = (double) vac_cost_limit / vac_cost_delay;
1820  dlist_foreach(iter, &AutoVacuumShmem->av_runningWorkers)
1821  {
1822  WorkerInfo worker = dlist_container(WorkerInfoData, wi_links, iter.cur);
1823 
1824  if (worker->wi_proc != NULL &&
1825  worker->wi_dobalance &&
1826  worker->wi_cost_limit_base > 0 && worker->wi_cost_delay > 0)
1827  {
1828  int limit = (int)
1829  (cost_avail * worker->wi_cost_limit_base / cost_total);
1830 
1831  /*
1832  * We put a lower bound of 1 on the cost_limit, to avoid division-
1833  * by-zero in the vacuum code. Also, in case of roundoff trouble
1834  * in these calculations, let's be sure we don't ever set
1835  * cost_limit to more than the base value.
1836  */
1837  worker->wi_cost_limit = Max(Min(limit,
1838  worker->wi_cost_limit_base),
1839  1);
1840  }
1841 
1842  if (worker->wi_proc != NULL)
1843  elog(DEBUG2, "autovac_balance_cost(pid=%u db=%u, rel=%u, dobalance=%s cost_limit=%d, cost_limit_base=%d, cost_delay=%g)",
1844  worker->wi_proc->pid, worker->wi_dboid, worker->wi_tableoid,
1845  worker->wi_dobalance ? "yes" : "no",
1846  worker->wi_cost_limit, worker->wi_cost_limit_base,
1847  worker->wi_cost_delay);
1848  }
1849 }
1850 
1851 /*
1852  * get_database_list
1853  * Return a list of all databases found in pg_database.
1854  *
1855  * The list and associated data is allocated in the caller's memory context,
1856  * which is in charge of ensuring that it's properly cleaned up afterwards.
1857  *
1858  * Note: this is the only function in which the autovacuum launcher uses a
1859  * transaction. Although we aren't attached to any particular database and
1860  * therefore can't access most catalogs, we do have enough infrastructure
1861  * to do a seqscan on pg_database.
1862  */
1863 static List *
1865 {
1866  List *dblist = NIL;
1867  Relation rel;
1868  TableScanDesc scan;
1869  HeapTuple tup;
1870  MemoryContext resultcxt;
1871 
1872  /* This is the context that we will allocate our output data in */
1873  resultcxt = CurrentMemoryContext;
1874 
1875  /*
1876  * Start a transaction so we can access pg_database, and get a snapshot.
1877  * We don't have a use for the snapshot itself, but we're interested in
1878  * the secondary effect that it sets RecentGlobalXmin. (This is critical
1879  * for anything that reads heap pages, because HOT may decide to prune
1880  * them even if the process doesn't attempt to modify any tuples.)
1881  */
1883  (void) GetTransactionSnapshot();
1884 
1885  rel = table_open(DatabaseRelationId, AccessShareLock);
1886  scan = table_beginscan_catalog(rel, 0, NULL);
1887 
1888  while (HeapTupleIsValid(tup = heap_getnext(scan, ForwardScanDirection)))
1889  {
1890  Form_pg_database pgdatabase = (Form_pg_database) GETSTRUCT(tup);
1891  avw_dbase *avdb;
1892  MemoryContext oldcxt;
1893 
1894  /*
1895  * Allocate our results in the caller's context, not the
1896  * transaction's. We do this inside the loop, and restore the original
1897  * context at the end, so that leaky things like heap_getnext() are
1898  * not called in a potentially long-lived context.
1899  */
1900  oldcxt = MemoryContextSwitchTo(resultcxt);
1901 
1902  avdb = (avw_dbase *) palloc(sizeof(avw_dbase));
1903 
1904  avdb->adw_datid = pgdatabase->oid;
1905  avdb->adw_name = pstrdup(NameStr(pgdatabase->datname));
1906  avdb->adw_frozenxid = pgdatabase->datfrozenxid;
1907  avdb->adw_minmulti = pgdatabase->datminmxid;
1908  /* this gets set later: */
1909  avdb->adw_entry = NULL;
1910 
1911  dblist = lappend(dblist, avdb);
1912  MemoryContextSwitchTo(oldcxt);
1913  }
1914 
1915  table_endscan(scan);
1917 
1919 
1920  return dblist;
1921 }
1922 
1923 /*
1924  * Process a database table-by-table
1925  *
1926  * Note that CHECK_FOR_INTERRUPTS is supposed to be used in certain spots in
1927  * order not to ignore shutdown commands for too long.
1928  */
1929 static void
1931 {
1932  Relation classRel;
1933  HeapTuple tuple;
1934  TableScanDesc relScan;
1935  Form_pg_database dbForm;
1936  List *table_oids = NIL;
1937  List *orphan_oids = NIL;
1938  HASHCTL ctl;
1939  HTAB *table_toast_map;
1940  ListCell *volatile cell;
1941  PgStat_StatDBEntry *shared;
1942  PgStat_StatDBEntry *dbentry;
1943  BufferAccessStrategy bstrategy;
1944  ScanKeyData key;
1945  TupleDesc pg_class_desc;
1946  int effective_multixact_freeze_max_age;
1947  bool did_vacuum = false;
1948  bool found_concurrent_worker = false;
1949  int i;
1950 
1951  /*
1952  * StartTransactionCommand and CommitTransactionCommand will automatically
1953  * switch to other contexts. We need this one to keep the list of
1954  * relations to vacuum/analyze across transactions.
1955  */
1956  AutovacMemCxt = AllocSetContextCreate(TopMemoryContext,
1957  "AV worker",
1959  MemoryContextSwitchTo(AutovacMemCxt);
1960 
1961  /*
1962  * may be NULL if we couldn't find an entry (only happens if we are
1963  * forcing a vacuum for anti-wrap purposes).
1964  */
1966 
1967  /* Start a transaction so our commands have one to play into. */
1969 
1970  /*
1971  * Clean up any dead statistics collector entries for this DB. We always
1972  * want to do this exactly once per DB-processing cycle, even if we find
1973  * nothing worth vacuuming in the database.
1974  */
1976 
1977  /*
1978  * Compute the multixact age for which freezing is urgent. This is
1979  * normally autovacuum_multixact_freeze_max_age, but may be less if we are
1980  * short of multixact member space.
1981  */
1982  effective_multixact_freeze_max_age = MultiXactMemberFreezeThreshold();
1983 
1984  /*
1985  * Find the pg_database entry and select the default freeze ages. We use
1986  * zero in template and nonconnectable databases, else the system-wide
1987  * default.
1988  */
1990  if (!HeapTupleIsValid(tuple))
1991  elog(ERROR, "cache lookup failed for database %u", MyDatabaseId);
1992  dbForm = (Form_pg_database) GETSTRUCT(tuple);
1993 
1994  if (dbForm->datistemplate || !dbForm->datallowconn)
1995  {
2000  }
2001  else
2002  {
2007  }
2008 
2009  ReleaseSysCache(tuple);
2010 
2011  /* StartTransactionCommand changed elsewhere */
2012  MemoryContextSwitchTo(AutovacMemCxt);
2013 
2014  /* The database hash where pgstat keeps shared relations */
2016 
2017  classRel = table_open(RelationRelationId, AccessShareLock);
2018 
2019  /* create a copy so we can use it after closing pg_class */
2020  pg_class_desc = CreateTupleDescCopy(RelationGetDescr(classRel));
2021 
2022  /* create hash table for toast <-> main relid mapping */
2023  MemSet(&ctl, 0, sizeof(ctl));
2024  ctl.keysize = sizeof(Oid);
2025  ctl.entrysize = sizeof(av_relation);
2026 
2027  table_toast_map = hash_create("TOAST to main relid map",
2028  100,
2029  &ctl,
2030  HASH_ELEM | HASH_BLOBS);
2031 
2032  /*
2033  * Scan pg_class to determine which tables to vacuum.
2034  *
2035  * We do this in two passes: on the first one we collect the list of plain
2036  * relations and materialized views, and on the second one we collect
2037  * TOAST tables. The reason for doing the second pass is that during it we
2038  * want to use the main relation's pg_class.reloptions entry if the TOAST
2039  * table does not have any, and we cannot obtain it unless we know
2040  * beforehand what's the main table OID.
2041  *
2042  * We need to check TOAST tables separately because in cases with short,
2043  * wide tables there might be proportionally much more activity in the
2044  * TOAST table than in its parent.
2045  */
2046  relScan = table_beginscan_catalog(classRel, 0, NULL);
2047 
2048  /*
2049  * On the first pass, we collect main tables to vacuum, and also the main
2050  * table relid to TOAST relid mapping.
2051  */
2052  while ((tuple = heap_getnext(relScan, ForwardScanDirection)) != NULL)
2053  {
2054  Form_pg_class classForm = (Form_pg_class) GETSTRUCT(tuple);
2055  PgStat_StatTabEntry *tabentry;
2056  AutoVacOpts *relopts;
2057  Oid relid;
2058  bool dovacuum;
2059  bool doanalyze;
2060  bool wraparound;
2061 
2062  if (classForm->relkind != RELKIND_RELATION &&
2063  classForm->relkind != RELKIND_MATVIEW)
2064  continue;
2065 
2066  relid = classForm->oid;
2067 
2068  /*
2069  * Check if it is a temp table (presumably, of some other backend's).
2070  * We cannot safely process other backends' temp tables.
2071  */
2072  if (classForm->relpersistence == RELPERSISTENCE_TEMP)
2073  {
2074  /*
2075  * We just ignore it if the owning backend is still active and
2076  * using the temporary schema. Also, for safety, ignore it if the
2077  * namespace doesn't exist or isn't a temp namespace after all.
2078  */
2079  if (checkTempNamespaceStatus(classForm->relnamespace) == TEMP_NAMESPACE_IDLE)
2080  {
2081  /*
2082  * The table seems to be orphaned -- although it might be that
2083  * the owning backend has already deleted it and exited; our
2084  * pg_class scan snapshot is not necessarily up-to-date
2085  * anymore, so we could be looking at a committed-dead entry.
2086  * Remember it so we can try to delete it later.
2087  */
2088  orphan_oids = lappend_oid(orphan_oids, relid);
2089  }
2090  continue;
2091  }
2092 
2093  /* Fetch reloptions and the pgstat entry for this table */
2094  relopts = extract_autovac_opts(tuple, pg_class_desc);
2095  tabentry = get_pgstat_tabentry_relid(relid, classForm->relisshared,
2096  shared, dbentry);
2097 
2098  /* Check if it needs vacuum or analyze */
2099  relation_needs_vacanalyze(relid, relopts, classForm, tabentry,
2100  effective_multixact_freeze_max_age,
2101  &dovacuum, &doanalyze, &wraparound);
2102 
2103  /* Relations that need work are added to table_oids */
2104  if (dovacuum || doanalyze)
2105  table_oids = lappend_oid(table_oids, relid);
2106 
2107  /*
2108  * Remember TOAST associations for the second pass. Note: we must do
2109  * this whether or not the table is going to be vacuumed, because we
2110  * don't automatically vacuum toast tables along the parent table.
2111  */
2112  if (OidIsValid(classForm->reltoastrelid))
2113  {
2114  av_relation *hentry;
2115  bool found;
2116 
2117  hentry = hash_search(table_toast_map,
2118  &classForm->reltoastrelid,
2119  HASH_ENTER, &found);
2120 
2121  if (!found)
2122  {
2123  /* hash_search already filled in the key */
2124  hentry->ar_relid = relid;
2125  hentry->ar_hasrelopts = false;
2126  if (relopts != NULL)
2127  {
2128  hentry->ar_hasrelopts = true;
2129  memcpy(&hentry->ar_reloptions, relopts,
2130  sizeof(AutoVacOpts));
2131  }
2132  }
2133  }
2134  }
2135 
2136  table_endscan(relScan);
2137 
2138  /* second pass: check TOAST tables */
2139  ScanKeyInit(&key,
2140  Anum_pg_class_relkind,
2141  BTEqualStrategyNumber, F_CHAREQ,
2142  CharGetDatum(RELKIND_TOASTVALUE));
2143 
2144  relScan = table_beginscan_catalog(classRel, 1, &key);
2145  while ((tuple = heap_getnext(relScan, ForwardScanDirection)) != NULL)
2146  {
2147  Form_pg_class classForm = (Form_pg_class) GETSTRUCT(tuple);
2148  PgStat_StatTabEntry *tabentry;
2149  Oid relid;
2150  AutoVacOpts *relopts = NULL;
2151  bool dovacuum;
2152  bool doanalyze;
2153  bool wraparound;
2154 
2155  /*
2156  * We cannot safely process other backends' temp tables, so skip 'em.
2157  */
2158  if (classForm->relpersistence == RELPERSISTENCE_TEMP)
2159  continue;
2160 
2161  relid = classForm->oid;
2162 
2163  /*
2164  * fetch reloptions -- if this toast table does not have them, try the
2165  * main rel
2166  */
2167  relopts = extract_autovac_opts(tuple, pg_class_desc);
2168  if (relopts == NULL)
2169  {
2170  av_relation *hentry;
2171  bool found;
2172 
2173  hentry = hash_search(table_toast_map, &relid, HASH_FIND, &found);
2174  if (found && hentry->ar_hasrelopts)
2175  relopts = &hentry->ar_reloptions;
2176  }
2177 
2178  /* Fetch the pgstat entry for this table */
2179  tabentry = get_pgstat_tabentry_relid(relid, classForm->relisshared,
2180  shared, dbentry);
2181 
2182  relation_needs_vacanalyze(relid, relopts, classForm, tabentry,
2183  effective_multixact_freeze_max_age,
2184  &dovacuum, &doanalyze, &wraparound);
2185 
2186  /* ignore analyze for toast tables */
2187  if (dovacuum)
2188  table_oids = lappend_oid(table_oids, relid);
2189  }
2190 
2191  table_endscan(relScan);
2192  table_close(classRel, AccessShareLock);
2193 
2194  /*
2195  * Recheck orphan temporary tables, and if they still seem orphaned, drop
2196  * them. We'll eat a transaction per dropped table, which might seem
2197  * excessive, but we should only need to do anything as a result of a
2198  * previous backend crash, so this should not happen often enough to
2199  * justify "optimizing". Using separate transactions ensures that we
2200  * don't bloat the lock table if there are many temp tables to be dropped,
2201  * and it ensures that we don't lose work if a deletion attempt fails.
2202  */
2203  foreach(cell, orphan_oids)
2204  {
2205  Oid relid = lfirst_oid(cell);
2206  Form_pg_class classForm;
2207  ObjectAddress object;
2208 
2209  /*
2210  * Check for user-requested abort.
2211  */
2213 
2214  /*
2215  * Try to lock the table. If we can't get the lock immediately,
2216  * somebody else is using (or dropping) the table, so it's not our
2217  * concern anymore. Having the lock prevents race conditions below.
2218  */
2220  continue;
2221 
2222  /*
2223  * Re-fetch the pg_class tuple and re-check whether it still seems to
2224  * be an orphaned temp table. If it's not there or no longer the same
2225  * relation, ignore it.
2226  */
2227  tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
2228  if (!HeapTupleIsValid(tuple))
2229  {
2230  /* be sure to drop useless lock so we don't bloat lock table */
2232  continue;
2233  }
2234  classForm = (Form_pg_class) GETSTRUCT(tuple);
2235 
2236  /*
2237  * Make all the same tests made in the loop above. In event of OID
2238  * counter wraparound, the pg_class entry we have now might be
2239  * completely unrelated to the one we saw before.
2240  */
2241  if (!((classForm->relkind == RELKIND_RELATION ||
2242  classForm->relkind == RELKIND_MATVIEW) &&
2243  classForm->relpersistence == RELPERSISTENCE_TEMP))
2244  {
2246  continue;
2247  }
2248 
2249  if (checkTempNamespaceStatus(classForm->relnamespace) != TEMP_NAMESPACE_IDLE)
2250  {
2252  continue;
2253  }
2254 
2255  /* OK, let's delete it */
2256  ereport(LOG,
2257  (errmsg("autovacuum: dropping orphan temp table \"%s.%s.%s\"",
2259  get_namespace_name(classForm->relnamespace),
2260  NameStr(classForm->relname))));
2261 
2262  object.classId = RelationRelationId;
2263  object.objectId = relid;
2264  object.objectSubId = 0;
2265  performDeletion(&object, DROP_CASCADE,
2269 
2270  /*
2271  * To commit the deletion, end current transaction and start a new
2272  * one. Note this also releases the lock we took.
2273  */
2276 
2277  /* StartTransactionCommand changed current memory context */
2278  MemoryContextSwitchTo(AutovacMemCxt);
2279  }
2280 
2281  /*
2282  * Create a buffer access strategy object for VACUUM to use. We want to
2283  * use the same one across all the vacuum operations we perform, since the
2284  * point is for VACUUM not to blow out the shared cache.
2285  */
2286  bstrategy = GetAccessStrategy(BAS_VACUUM);
2287 
2288  /*
2289  * create a memory context to act as fake PortalContext, so that the
2290  * contexts created in the vacuum code are cleaned up for each table.
2291  */
2292  PortalContext = AllocSetContextCreate(AutovacMemCxt,
2293  "Autovacuum Portal",
2295 
2296  /*
2297  * Perform operations on collected tables.
2298  */
2299  foreach(cell, table_oids)
2300  {
2301  Oid relid = lfirst_oid(cell);
2302  HeapTuple classTup;
2303  autovac_table *tab;
2304  bool isshared;
2305  bool skipit;
2306  double stdVacuumCostDelay;
2307  int stdVacuumCostLimit;
2308  dlist_iter iter;
2309 
2311 
2312  /*
2313  * Check for config changes before processing each collected table.
2314  */
2315  if (ConfigReloadPending)
2316  {
2317  ConfigReloadPending = false;
2319 
2320  /*
2321  * You might be tempted to bail out if we see autovacuum is now
2322  * disabled. Must resist that temptation -- this might be a
2323  * for-wraparound emergency worker, in which case that would be
2324  * entirely inappropriate.
2325  */
2326  }
2327 
2328  /*
2329  * Find out whether the table is shared or not. (It's slightly
2330  * annoying to fetch the syscache entry just for this, but in typical
2331  * cases it adds little cost because table_recheck_autovac would
2332  * refetch the entry anyway. We could buy that back by copying the
2333  * tuple here and passing it to table_recheck_autovac, but that
2334  * increases the odds of that function working with stale data.)
2335  */
2336  classTup = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
2337  if (!HeapTupleIsValid(classTup))
2338  continue; /* somebody deleted the rel, forget it */
2339  isshared = ((Form_pg_class) GETSTRUCT(classTup))->relisshared;
2340  ReleaseSysCache(classTup);
2341 
2342  /*
2343  * Hold schedule lock from here until we've claimed the table. We
2344  * also need the AutovacuumLock to walk the worker array, but that one
2345  * can just be a shared lock.
2346  */
2347  LWLockAcquire(AutovacuumScheduleLock, LW_EXCLUSIVE);
2348  LWLockAcquire(AutovacuumLock, LW_SHARED);
2349 
2350  /*
2351  * Check whether the table is being vacuumed concurrently by another
2352  * worker.
2353  */
2354  skipit = false;
2355  dlist_foreach(iter, &AutoVacuumShmem->av_runningWorkers)
2356  {
2357  WorkerInfo worker = dlist_container(WorkerInfoData, wi_links, iter.cur);
2358 
2359  /* ignore myself */
2360  if (worker == MyWorkerInfo)
2361  continue;
2362 
2363  /* ignore workers in other databases (unless table is shared) */
2364  if (!worker->wi_sharedrel && worker->wi_dboid != MyDatabaseId)
2365  continue;
2366 
2367  if (worker->wi_tableoid == relid)
2368  {
2369  skipit = true;
2370  found_concurrent_worker = true;
2371  break;
2372  }
2373  }
2374  LWLockRelease(AutovacuumLock);
2375  if (skipit)
2376  {
2377  LWLockRelease(AutovacuumScheduleLock);
2378  continue;
2379  }
2380 
2381  /*
2382  * Store the table's OID in shared memory before releasing the
2383  * schedule lock, so that other workers don't try to vacuum it
2384  * concurrently. (We claim it here so as not to hold
2385  * AutovacuumScheduleLock while rechecking the stats.)
2386  */
2387  MyWorkerInfo->wi_tableoid = relid;
2388  MyWorkerInfo->wi_sharedrel = isshared;
2389  LWLockRelease(AutovacuumScheduleLock);
2390 
2391  /*
2392  * Check whether pgstat data still says we need to vacuum this table.
2393  * It could have changed if something else processed the table while
2394  * we weren't looking.
2395  *
2396  * Note: we have a special case in pgstat code to ensure that the
2397  * stats we read are as up-to-date as possible, to avoid the problem
2398  * that somebody just finished vacuuming this table. The window to
2399  * the race condition is not closed but it is very small.
2400  */
2401  MemoryContextSwitchTo(AutovacMemCxt);
2402  tab = table_recheck_autovac(relid, table_toast_map, pg_class_desc,
2403  effective_multixact_freeze_max_age);
2404  if (tab == NULL)
2405  {
2406  /* someone else vacuumed the table, or it went away */
2407  LWLockAcquire(AutovacuumScheduleLock, LW_EXCLUSIVE);
2408  MyWorkerInfo->wi_tableoid = InvalidOid;
2409  MyWorkerInfo->wi_sharedrel = false;
2410  LWLockRelease(AutovacuumScheduleLock);
2411  continue;
2412  }
2413 
2414  /*
2415  * Remember the prevailing values of the vacuum cost GUCs. We have to
2416  * restore these at the bottom of the loop, else we'll compute wrong
2417  * values in the next iteration of autovac_balance_cost().
2418  */
2419  stdVacuumCostDelay = VacuumCostDelay;
2420  stdVacuumCostLimit = VacuumCostLimit;
2421 
2422  /* Must hold AutovacuumLock while mucking with cost balance info */
2423  LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
2424 
2425  /* advertise my cost delay parameters for the balancing algorithm */
2426  MyWorkerInfo->wi_dobalance = tab->at_dobalance;
2427  MyWorkerInfo->wi_cost_delay = tab->at_vacuum_cost_delay;
2428  MyWorkerInfo->wi_cost_limit = tab->at_vacuum_cost_limit;
2429  MyWorkerInfo->wi_cost_limit_base = tab->at_vacuum_cost_limit;
2430 
2431  /* do a balance */
2433 
2434  /* set the active cost parameters from the result of that */
2436 
2437  /* done */
2438  LWLockRelease(AutovacuumLock);
2439 
2440  /* clean up memory before each iteration */
2442 
2443  /*
2444  * Save the relation name for a possible error message, to avoid a
2445  * catalog lookup in case of an error. If any of these return NULL,
2446  * then the relation has been dropped since last we checked; skip it.
2447  * Note: they must live in a long-lived memory context because we call
2448  * vacuum and analyze in different transactions.
2449  */
2450 
2451  tab->at_relname = get_rel_name(tab->at_relid);
2454  if (!tab->at_relname || !tab->at_nspname || !tab->at_datname)
2455  goto deleted;
2456 
2457  /*
2458  * We will abort vacuuming the current table if something errors out,
2459  * and continue with the next one in schedule; in particular, this
2460  * happens if we are interrupted with SIGINT.
2461  */
2462  PG_TRY();
2463  {
2464  /* Use PortalContext for any per-table allocations */
2466 
2467  /* have at it */
2468  autovacuum_do_vac_analyze(tab, bstrategy);
2469 
2470  /*
2471  * Clear a possible query-cancel signal, to avoid a late reaction
2472  * to an automatically-sent signal because of vacuuming the
2473  * current table (we're done with it, so it would make no sense to
2474  * cancel at this point.)
2475  */
2476  QueryCancelPending = false;
2477  }
2478  PG_CATCH();
2479  {
2480  /*
2481  * Abort the transaction, start a new one, and proceed with the
2482  * next table in our list.
2483  */
2484  HOLD_INTERRUPTS();
2485  if (tab->at_params.options & VACOPT_VACUUM)
2486  errcontext("automatic vacuum of table \"%s.%s.%s\"",
2487  tab->at_datname, tab->at_nspname, tab->at_relname);
2488  else
2489  errcontext("automatic analyze of table \"%s.%s.%s\"",
2490  tab->at_datname, tab->at_nspname, tab->at_relname);
2491  EmitErrorReport();
2492 
2493  /* this resets the PGXACT flags too */
2495  FlushErrorState();
2497 
2498  /* restart our transaction for the following operations */
2501  }
2502  PG_END_TRY();
2503 
2504  /* Make sure we're back in AutovacMemCxt */
2505  MemoryContextSwitchTo(AutovacMemCxt);
2506 
2507  did_vacuum = true;
2508 
2509  /* the PGXACT flags are reset at the next end of transaction */
2510 
2511  /* be tidy */
2512 deleted:
2513  if (tab->at_datname != NULL)
2514  pfree(tab->at_datname);
2515  if (tab->at_nspname != NULL)
2516  pfree(tab->at_nspname);
2517  if (tab->at_relname != NULL)
2518  pfree(tab->at_relname);
2519  pfree(tab);
2520 
2521  /*
2522  * Remove my info from shared memory. We could, but intentionally
2523  * don't, clear wi_cost_limit and friends --- this is on the
2524  * assumption that we probably have more to do with similar cost
2525  * settings, so we don't want to give up our share of I/O for a very
2526  * short interval and thereby thrash the global balance.
2527  */
2528  LWLockAcquire(AutovacuumScheduleLock, LW_EXCLUSIVE);
2529  MyWorkerInfo->wi_tableoid = InvalidOid;
2530  MyWorkerInfo->wi_sharedrel = false;
2531  LWLockRelease(AutovacuumScheduleLock);
2532 
2533  /* restore vacuum cost GUCs for the next iteration */
2534  VacuumCostDelay = stdVacuumCostDelay;
2535  VacuumCostLimit = stdVacuumCostLimit;
2536  }
2537 
2538  /*
2539  * Perform additional work items, as requested by backends.
2540  */
2541  LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
2542  for (i = 0; i < NUM_WORKITEMS; i++)
2543  {
2544  AutoVacuumWorkItem *workitem = &AutoVacuumShmem->av_workItems[i];
2545 
2546  if (!workitem->avw_used)
2547  continue;
2548  if (workitem->avw_active)
2549  continue;
2550  if (workitem->avw_database != MyDatabaseId)
2551  continue;
2552 
2553  /* claim this one, and release lock while performing it */
2554  workitem->avw_active = true;
2555  LWLockRelease(AutovacuumLock);
2556 
2557  perform_work_item(workitem);
2558 
2559  /*
2560  * Check for config changes before acquiring lock for further jobs.
2561  */
2563  if (ConfigReloadPending)
2564  {
2565  ConfigReloadPending = false;
2567  }
2568 
2569  LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
2570 
2571  /* and mark it done */
2572  workitem->avw_active = false;
2573  workitem->avw_used = false;
2574  }
2575  LWLockRelease(AutovacuumLock);
2576 
2577  /*
2578  * We leak table_toast_map here (among other things), but since we're
2579  * going away soon, it's not a problem.
2580  */
2581 
2582  /*
2583  * Update pg_database.datfrozenxid, and truncate pg_xact if possible. We
2584  * only need to do this once, not after each table.
2585  *
2586  * Even if we didn't vacuum anything, it may still be important to do
2587  * this, because one indirect effect of vac_update_datfrozenxid() is to
2588  * update ShmemVariableCache->xidVacLimit. That might need to be done
2589  * even if we haven't vacuumed anything, because relations with older
2590  * relfrozenxid values or other databases with older datfrozenxid values
2591  * might have been dropped, allowing xidVacLimit to advance.
2592  *
2593  * However, it's also important not to do this blindly in all cases,
2594  * because when autovacuum=off this will restart the autovacuum launcher.
2595  * If we're not careful, an infinite loop can result, where workers find
2596  * no work to do and restart the launcher, which starts another worker in
2597  * the same database that finds no work to do. To prevent that, we skip
2598  * this if (1) we found no work to do and (2) we skipped at least one
2599  * table due to concurrent autovacuum activity. In that case, the other
2600  * worker has already done it, or will do so when it finishes.
2601  */
2602  if (did_vacuum || !found_concurrent_worker)
2604 
2605  /* Finally close out the last transaction. */
2607 }
2608 
2609 /*
2610  * Execute a previously registered work item.
2611  */
2612 static void
2614 {
2615  char *cur_datname = NULL;
2616  char *cur_nspname = NULL;
2617  char *cur_relname = NULL;
2618 
2619  /*
2620  * Note we do not store table info in MyWorkerInfo, since this is not
2621  * vacuuming proper.
2622  */
2623 
2624  /*
2625  * Save the relation name for a possible error message, to avoid a catalog
2626  * lookup in case of an error. If any of these return NULL, then the
2627  * relation has been dropped since last we checked; skip it.
2628  */
2629  Assert(CurrentMemoryContext == AutovacMemCxt);
2630 
2631  cur_relname = get_rel_name(workitem->avw_relation);
2632  cur_nspname = get_namespace_name(get_rel_namespace(workitem->avw_relation));
2633  cur_datname = get_database_name(MyDatabaseId);
2634  if (!cur_relname || !cur_nspname || !cur_datname)
2635  goto deleted2;
2636 
2637  autovac_report_workitem(workitem, cur_nspname, cur_relname);
2638 
2639  /* clean up memory before each work item */
2641 
2642  /*
2643  * We will abort the current work item if something errors out, and
2644  * continue with the next one; in particular, this happens if we are
2645  * interrupted with SIGINT. Note that this means that the work item list
2646  * can be lossy.
2647  */
2648  PG_TRY();
2649  {
2650  /* Use PortalContext for any per-work-item allocations */
2652 
2653  /* have at it */
2654  switch (workitem->avw_type)
2655  {
2658  ObjectIdGetDatum(workitem->avw_relation),
2659  Int64GetDatum((int64) workitem->avw_blockNumber));
2660  break;
2661  default:
2662  elog(WARNING, "unrecognized work item found: type %d",
2663  workitem->avw_type);
2664  break;
2665  }
2666 
2667  /*
2668  * Clear a possible query-cancel signal, to avoid a late reaction to
2669  * an automatically-sent signal because of vacuuming the current table
2670  * (we're done with it, so it would make no sense to cancel at this
2671  * point.)
2672  */
2673  QueryCancelPending = false;
2674  }
2675  PG_CATCH();
2676  {
2677  /*
2678  * Abort the transaction, start a new one, and proceed with the next
2679  * table in our list.
2680  */
2681  HOLD_INTERRUPTS();
2682  errcontext("processing work entry for relation \"%s.%s.%s\"",
2683  cur_datname, cur_nspname, cur_relname);
2684  EmitErrorReport();
2685 
2686  /* this resets the PGXACT flags too */
2688  FlushErrorState();
2690 
2691  /* restart our transaction for the following operations */
2694  }
2695  PG_END_TRY();
2696 
2697  /* Make sure we're back in AutovacMemCxt */
2698  MemoryContextSwitchTo(AutovacMemCxt);
2699 
2700  /* We intentionally do not set did_vacuum here */
2701 
2702  /* be tidy */
2703 deleted2:
2704  if (cur_datname)
2705  pfree(cur_datname);
2706  if (cur_nspname)
2707  pfree(cur_nspname);
2708  if (cur_relname)
2709  pfree(cur_relname);
2710 }
2711 
2712 /*
2713  * extract_autovac_opts
2714  *
2715  * Given a relation's pg_class tuple, return the AutoVacOpts portion of
2716  * reloptions, if set; otherwise, return NULL.
2717  */
2718 static AutoVacOpts *
2720 {
2721  bytea *relopts;
2722  AutoVacOpts *av;
2723 
2724  Assert(((Form_pg_class) GETSTRUCT(tup))->relkind == RELKIND_RELATION ||
2725  ((Form_pg_class) GETSTRUCT(tup))->relkind == RELKIND_MATVIEW ||
2726  ((Form_pg_class) GETSTRUCT(tup))->relkind == RELKIND_TOASTVALUE);
2727 
2728  relopts = extractRelOptions(tup, pg_class_desc, NULL);
2729  if (relopts == NULL)
2730  return NULL;
2731 
2732  av = palloc(sizeof(AutoVacOpts));
2733  memcpy(av, &(((StdRdOptions *) relopts)->autovacuum), sizeof(AutoVacOpts));
2734  pfree(relopts);
2735 
2736  return av;
2737 }
2738 
2739 /*
2740  * get_pgstat_tabentry_relid
2741  *
2742  * Fetch the pgstat entry of a table, either local to a database or shared.
2743  */
2744 static PgStat_StatTabEntry *
2745 get_pgstat_tabentry_relid(Oid relid, bool isshared, PgStat_StatDBEntry *shared,
2746  PgStat_StatDBEntry *dbentry)
2747 {
2748  PgStat_StatTabEntry *tabentry = NULL;
2749 
2750  if (isshared)
2751  {
2752  if (PointerIsValid(shared))
2753  tabentry = hash_search(shared->tables, &relid,
2754  HASH_FIND, NULL);
2755  }
2756  else if (PointerIsValid(dbentry))
2757  tabentry = hash_search(dbentry->tables, &relid,
2758  HASH_FIND, NULL);
2759 
2760  return tabentry;
2761 }
2762 
2763 /*
2764  * table_recheck_autovac
2765  *
2766  * Recheck whether a table still needs vacuum or analyze. Return value is a
2767  * valid autovac_table pointer if it does, NULL otherwise.
2768  *
2769  * Note that the returned autovac_table does not have the name fields set.
2770  */
2771 static autovac_table *
2772 table_recheck_autovac(Oid relid, HTAB *table_toast_map,
2773  TupleDesc pg_class_desc,
2774  int effective_multixact_freeze_max_age)
2775 {
2776  Form_pg_class classForm;
2777  HeapTuple classTup;
2778  bool dovacuum;
2779  bool doanalyze;
2780  autovac_table *tab = NULL;
2781  PgStat_StatTabEntry *tabentry;
2782  PgStat_StatDBEntry *shared;
2783  PgStat_StatDBEntry *dbentry;
2784  bool wraparound;
2785  AutoVacOpts *avopts;
2786 
2787  /* use fresh stats */
2789 
2792 
2793  /* fetch the relation's relcache entry */
2794  classTup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
2795  if (!HeapTupleIsValid(classTup))
2796  return NULL;
2797  classForm = (Form_pg_class) GETSTRUCT(classTup);
2798 
2799  /*
2800  * Get the applicable reloptions. If it is a TOAST table, try to get the
2801  * main table reloptions if the toast table itself doesn't have.
2802  */
2803  avopts = extract_autovac_opts(classTup, pg_class_desc);
2804  if (classForm->relkind == RELKIND_TOASTVALUE &&
2805  avopts == NULL && table_toast_map != NULL)
2806  {
2807  av_relation *hentry;
2808  bool found;
2809 
2810  hentry = hash_search(table_toast_map, &relid, HASH_FIND, &found);
2811  if (found && hentry->ar_hasrelopts)
2812  avopts = &hentry->ar_reloptions;
2813  }
2814 
2815  /* fetch the pgstat table entry */
2816  tabentry = get_pgstat_tabentry_relid(relid, classForm->relisshared,
2817  shared, dbentry);
2818 
2819  relation_needs_vacanalyze(relid, avopts, classForm, tabentry,
2820  effective_multixact_freeze_max_age,
2821  &dovacuum, &doanalyze, &wraparound);
2822 
2823  /* ignore ANALYZE for toast tables */
2824  if (classForm->relkind == RELKIND_TOASTVALUE)
2825  doanalyze = false;
2826 
2827  /* OK, it needs something done */
2828  if (doanalyze || dovacuum)
2829  {
2830  int freeze_min_age;
2831  int freeze_table_age;
2832  int multixact_freeze_min_age;
2833  int multixact_freeze_table_age;
2834  int vac_cost_limit;
2835  double vac_cost_delay;
2836  int log_min_duration;
2837 
2838  /*
2839  * Calculate the vacuum cost parameters and the freeze ages. If there
2840  * are options set in pg_class.reloptions, use them; in the case of a
2841  * toast table, try the main table too. Otherwise use the GUC
2842  * defaults, autovacuum's own first and plain vacuum second.
2843  */
2844 
2845  /* -1 in autovac setting means use plain vacuum_cost_delay */
2846  vac_cost_delay = (avopts && avopts->vacuum_cost_delay >= 0)
2847  ? avopts->vacuum_cost_delay
2848  : (autovacuum_vac_cost_delay >= 0)
2850  : VacuumCostDelay;
2851 
2852  /* 0 or -1 in autovac setting means use plain vacuum_cost_limit */
2853  vac_cost_limit = (avopts && avopts->vacuum_cost_limit > 0)
2854  ? avopts->vacuum_cost_limit
2857  : VacuumCostLimit;
2858 
2859  /* -1 in autovac setting means use log_autovacuum_min_duration */
2860  log_min_duration = (avopts && avopts->log_min_duration >= 0)
2861  ? avopts->log_min_duration
2863 
2864  /* these do not have autovacuum-specific settings */
2865  freeze_min_age = (avopts && avopts->freeze_min_age >= 0)
2866  ? avopts->freeze_min_age
2868 
2869  freeze_table_age = (avopts && avopts->freeze_table_age >= 0)
2870  ? avopts->freeze_table_age
2872 
2873  multixact_freeze_min_age = (avopts &&
2874  avopts->multixact_freeze_min_age >= 0)
2875  ? avopts->multixact_freeze_min_age
2877 
2878  multixact_freeze_table_age = (avopts &&
2879  avopts->multixact_freeze_table_age >= 0)
2880  ? avopts->multixact_freeze_table_age
2882 
2883  tab = palloc(sizeof(autovac_table));
2884  tab->at_relid = relid;
2885  tab->at_sharedrel = classForm->relisshared;
2887  (dovacuum ? VACOPT_VACUUM : 0) |
2888  (doanalyze ? VACOPT_ANALYZE : 0) |
2889  (!wraparound ? VACOPT_SKIP_LOCKED : 0);
2892  /* As of now, we don't support parallel vacuum for autovacuum */
2893  tab->at_params.nworkers = -1;
2894  tab->at_params.freeze_min_age = freeze_min_age;
2895  tab->at_params.freeze_table_age = freeze_table_age;
2896  tab->at_params.multixact_freeze_min_age = multixact_freeze_min_age;
2897  tab->at_params.multixact_freeze_table_age = multixact_freeze_table_age;
2898  tab->at_params.is_wraparound = wraparound;
2899  tab->at_params.log_min_duration = log_min_duration;
2900  tab->at_vacuum_cost_limit = vac_cost_limit;
2901  tab->at_vacuum_cost_delay = vac_cost_delay;
2902  tab->at_relname = NULL;
2903  tab->at_nspname = NULL;
2904  tab->at_datname = NULL;
2905 
2906  /*
2907  * If any of the cost delay parameters has been set individually for
2908  * this table, disable the balancing algorithm.
2909  */
2910  tab->at_dobalance =
2911  !(avopts && (avopts->vacuum_cost_limit > 0 ||
2912  avopts->vacuum_cost_delay > 0));
2913  }
2914 
2915  heap_freetuple(classTup);
2916 
2917  return tab;
2918 }
2919 
2920 /*
2921  * relation_needs_vacanalyze
2922  *
2923  * Check whether a relation needs to be vacuumed or analyzed; return each into
2924  * "dovacuum" and "doanalyze", respectively. Also return whether the vacuum is
2925  * being forced because of Xid or multixact wraparound.
2926  *
2927  * relopts is a pointer to the AutoVacOpts options (either for itself in the
2928  * case of a plain table, or for either itself or its parent table in the case
2929  * of a TOAST table), NULL if none; tabentry is the pgstats entry, which can be
2930  * NULL.
2931  *
2932  * A table needs to be vacuumed if the number of dead tuples exceeds a
2933  * threshold. This threshold is calculated as
2934  *
2935  * threshold = vac_base_thresh + vac_scale_factor * reltuples
2936  *
2937  * For analyze, the analysis done is that the number of tuples inserted,
2938  * deleted and updated since the last analyze exceeds a threshold calculated
2939  * in the same fashion as above. Note that the collector actually stores
2940  * the number of tuples (both live and dead) that there were as of the last
2941  * analyze. This is asymmetric to the VACUUM case.
2942  *
2943  * We also force vacuum if the table's relfrozenxid is more than freeze_max_age
2944  * transactions back, and if its relminmxid is more than
2945  * multixact_freeze_max_age multixacts back.
2946  *
2947  * A table whose autovacuum_enabled option is false is
2948  * automatically skipped (unless we have to vacuum it due to freeze_max_age).
2949  * Thus autovacuum can be disabled for specific tables. Also, when the stats
2950  * collector does not have data about a table, it will be skipped.
2951  *
2952  * A table whose vac_base_thresh value is < 0 takes the base value from the
2953  * autovacuum_vacuum_threshold GUC variable. Similarly, a vac_scale_factor
2954  * value < 0 is substituted with the value of
2955  * autovacuum_vacuum_scale_factor GUC variable. Ditto for analyze.
2956  */
2957 static void
2959  AutoVacOpts *relopts,
2960  Form_pg_class classForm,
2961  PgStat_StatTabEntry *tabentry,
2962  int effective_multixact_freeze_max_age,
2963  /* output params below */
2964  bool *dovacuum,
2965  bool *doanalyze,
2966  bool *wraparound)
2967 {
2968  bool force_vacuum;
2969  bool av_enabled;
2970  float4 reltuples; /* pg_class.reltuples */
2971 
2972  /* constants from reloptions or GUC variables */
2973  int vac_base_thresh,
2974  vac_ins_base_thresh,
2975  anl_base_thresh;
2976  float4 vac_scale_factor,
2977  vac_ins_scale_factor,
2978  anl_scale_factor;
2979 
2980  /* thresholds calculated from above constants */
2981  float4 vacthresh,
2982  vacinsthresh,
2983  anlthresh;
2984 
2985  /* number of vacuum (resp. analyze) tuples at this time */
2986  float4 vactuples,
2987  instuples,
2988  anltuples;
2989 
2990  /* freeze parameters */
2991  int freeze_max_age;
2992  int multixact_freeze_max_age;
2993  TransactionId xidForceLimit;
2994  MultiXactId multiForceLimit;
2995 
2996  AssertArg(classForm != NULL);
2997  AssertArg(OidIsValid(relid));
2998 
2999  /*
3000  * Determine vacuum/analyze equation parameters. We have two possible
3001  * sources: the passed reloptions (which could be a main table or a toast
3002  * table), or the autovacuum GUC variables.
3003  */
3004 
3005  /* -1 in autovac setting means use plain vacuum_scale_factor */
3006  vac_scale_factor = (relopts && relopts->vacuum_scale_factor >= 0)
3007  ? relopts->vacuum_scale_factor
3009 
3010  vac_base_thresh = (relopts && relopts->vacuum_threshold >= 0)
3011  ? relopts->vacuum_threshold
3013 
3014  vac_ins_scale_factor = (relopts && relopts->vacuum_ins_scale_factor >= 0)
3015  ? relopts->vacuum_ins_scale_factor
3017 
3018  /* -1 is used to disable insert vacuums */
3019  vac_ins_base_thresh = (relopts && relopts->vacuum_ins_threshold >= -1)
3020  ? relopts->vacuum_ins_threshold
3022 
3023  anl_scale_factor = (relopts && relopts->analyze_scale_factor >= 0)
3024  ? relopts->analyze_scale_factor
3026 
3027  anl_base_thresh = (relopts && relopts->analyze_threshold >= 0)
3028  ? relopts->analyze_threshold
3030 
3031  freeze_max_age = (relopts && relopts->freeze_max_age >= 0)
3034 
3035  multixact_freeze_max_age = (relopts && relopts->multixact_freeze_max_age >= 0)
3036  ? Min(relopts->multixact_freeze_max_age, effective_multixact_freeze_max_age)
3037  : effective_multixact_freeze_max_age;
3038 
3039  av_enabled = (relopts ? relopts->enabled : true);
3040 
3041  /* Force vacuum if table is at risk of wraparound */
3042  xidForceLimit = recentXid - freeze_max_age;
3043  if (xidForceLimit < FirstNormalTransactionId)
3044  xidForceLimit -= FirstNormalTransactionId;
3045  force_vacuum = (TransactionIdIsNormal(classForm->relfrozenxid) &&
3046  TransactionIdPrecedes(classForm->relfrozenxid,
3047  xidForceLimit));
3048  if (!force_vacuum)
3049  {
3050  multiForceLimit = recentMulti - multixact_freeze_max_age;
3051  if (multiForceLimit < FirstMultiXactId)
3052  multiForceLimit -= FirstMultiXactId;
3053  force_vacuum = MultiXactIdIsValid(classForm->relminmxid) &&
3054  MultiXactIdPrecedes(classForm->relminmxid, multiForceLimit);
3055  }
3056  *wraparound = force_vacuum;
3057 
3058  /* User disabled it in pg_class.reloptions? (But ignore if at risk) */
3059  if (!av_enabled && !force_vacuum)
3060  {
3061  *doanalyze = false;
3062  *dovacuum = false;
3063  return;
3064  }
3065 
3066  /*
3067  * If we found the table in the stats hash, and autovacuum is currently
3068  * enabled, make a threshold-based decision whether to vacuum and/or
3069  * analyze. If autovacuum is currently disabled, we must be here for
3070  * anti-wraparound vacuuming only, so don't vacuum (or analyze) anything
3071  * that's not being forced.
3072  */
3073  if (PointerIsValid(tabentry) && AutoVacuumingActive())
3074  {
3075  reltuples = classForm->reltuples;
3076  vactuples = tabentry->n_dead_tuples;
3077  instuples = tabentry->inserts_since_vacuum;
3078  anltuples = tabentry->changes_since_analyze;
3079 
3080  vacthresh = (float4) vac_base_thresh + vac_scale_factor * reltuples;
3081  vacinsthresh = (float4) vac_ins_base_thresh + vac_ins_scale_factor * reltuples;
3082  anlthresh = (float4) anl_base_thresh + anl_scale_factor * reltuples;
3083 
3084  /*
3085  * Note that we don't need to take special consideration for stat
3086  * reset, because if that happens, the last vacuum and analyze counts
3087  * will be reset too.
3088  */
3089  if (vac_ins_base_thresh >= 0)
3090  elog(DEBUG3, "%s: vac: %.0f (threshold %.0f), ins: %.0f (threshold %.0f), anl: %.0f (threshold %.0f)",
3091  NameStr(classForm->relname),
3092  vactuples, vacthresh, instuples, vacinsthresh, anltuples, anlthresh);
3093  else
3094  elog(DEBUG3, "%s: vac: %.0f (threshold %.0f), ins: (disabled), anl: %.0f (threshold %.0f)",
3095  NameStr(classForm->relname),
3096  vactuples, vacthresh, anltuples, anlthresh);
3097 
3098  /* Determine if this table needs vacuum or analyze. */
3099  *dovacuum = force_vacuum || (vactuples > vacthresh) ||
3100  (vac_ins_base_thresh >= 0 && instuples > vacinsthresh);
3101  *doanalyze = (anltuples > anlthresh);
3102  }
3103  else
3104  {
3105  /*
3106  * Skip a table not found in stat hash, unless we have to force vacuum
3107  * for anti-wrap purposes. If it's not acted upon, there's no need to
3108  * vacuum it.
3109  */
3110  *dovacuum = force_vacuum;
3111  *doanalyze = false;
3112  }
3113 
3114  /* ANALYZE refuses to work with pg_statistic */
3115  if (relid == StatisticRelationId)
3116  *doanalyze = false;
3117 }
3118 
3119 /*
3120  * autovacuum_do_vac_analyze
3121  * Vacuum and/or analyze the specified table
3122  */
3123 static void
3125 {
3126  RangeVar *rangevar;
3127  VacuumRelation *rel;
3128  List *rel_list;
3129 
3130  /* Let pgstat know what we're doing */
3132 
3133  /* Set up one VacuumRelation target, identified by OID, for vacuum() */
3134  rangevar = makeRangeVar(tab->at_nspname, tab->at_relname, -1);
3135  rel = makeVacuumRelation(rangevar, tab->at_relid, NIL);
3136  rel_list = list_make1(rel);
3137 
3138  vacuum(rel_list, &tab->at_params, bstrategy, true);
3139 }
3140 
3141 /*
3142  * autovac_report_activity
3143  * Report to pgstat what autovacuum is doing
3144  *
3145  * We send a SQL string corresponding to what the user would see if the
3146  * equivalent command was to be issued manually.
3147  *
3148  * Note we assume that we are going to report the next command as soon as we're
3149  * done with the current one, and exit right after the last one, so we don't
3150  * bother to report "<IDLE>" or some such.
3151  */
3152 static void
3154 {
3155 #define MAX_AUTOVAC_ACTIV_LEN (NAMEDATALEN * 2 + 56)
3156  char activity[MAX_AUTOVAC_ACTIV_LEN];
3157  int len;
3158 
3159  /* Report the command and possible options */
3160  if (tab->at_params.options & VACOPT_VACUUM)
3161  snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
3162  "autovacuum: VACUUM%s",
3163  tab->at_params.options & VACOPT_ANALYZE ? " ANALYZE" : "");
3164  else
3165  snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
3166  "autovacuum: ANALYZE");
3167 
3168  /*
3169  * Report the qualified name of the relation.
3170  */
3171  len = strlen(activity);
3172 
3173  snprintf(activity + len, MAX_AUTOVAC_ACTIV_LEN - len,
3174  " %s.%s%s", tab->at_nspname, tab->at_relname,
3175  tab->at_params.is_wraparound ? " (to prevent wraparound)" : "");
3176 
3177  /* Set statement_timestamp() to current time for pg_stat_activity */
3179 
3181 }
3182 
3183 /*
3184  * autovac_report_workitem
3185  * Report to pgstat that autovacuum is processing a work item
3186  */
3187 static void
3189  const char *nspname, const char *relname)
3190 {
3191  char activity[MAX_AUTOVAC_ACTIV_LEN + 12 + 2];
3192  char blk[12 + 2];
3193  int len;
3194 
3195  switch (workitem->avw_type)
3196  {
3198  snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
3199  "autovacuum: BRIN summarize");
3200  break;
3201  }
3202 
3203  /*
3204  * Report the qualified name of the relation, and the block number if any
3205  */
3206  len = strlen(activity);
3207 
3208  if (BlockNumberIsValid(workitem->avw_blockNumber))
3209  snprintf(blk, sizeof(blk), " %u", workitem->avw_blockNumber);
3210  else
3211  blk[0] = '\0';
3212 
3213  snprintf(activity + len, MAX_AUTOVAC_ACTIV_LEN - len,
3214  " %s.%s%s", nspname, relname, blk);
3215 
3216  /* Set statement_timestamp() to current time for pg_stat_activity */
3218 
3220 }
3221 
3222 /*
3223  * AutoVacuumingActive
3224  * Check GUC vars and report whether the autovacuum process should be
3225  * running.
3226  */
3227 bool
3229 {
3231  return false;
3232  return true;
3233 }
3234 
3235 /*
3236  * Request one work item to the next autovacuum run processing our database.
3237  * Return false if the request can't be recorded.
3238  */
3239 bool
3241  BlockNumber blkno)
3242 {
3243  int i;
3244  bool result = false;
3245 
3246  LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
3247 
3248  /*
3249  * Locate an unused work item and fill it with the given data.
3250  */
3251  for (i = 0; i < NUM_WORKITEMS; i++)
3252  {
3253  AutoVacuumWorkItem *workitem = &AutoVacuumShmem->av_workItems[i];
3254 
3255  if (workitem->avw_used)
3256  continue;
3257 
3258  workitem->avw_used = true;
3259  workitem->avw_active = false;
3260  workitem->avw_type = type;
3261  workitem->avw_database = MyDatabaseId;
3262  workitem->avw_relation = relationId;
3263  workitem->avw_blockNumber = blkno;
3264  result = true;
3265 
3266  /* done */
3267  break;
3268  }
3269 
3270  LWLockRelease(AutovacuumLock);
3271 
3272  return result;
3273 }
3274 
3275 /*
3276  * autovac_init
3277  * This is called at postmaster initialization.
3278  *
3279  * All we do here is annoy the user if he got it wrong.
3280  */
3281 void
3283 {
3285  ereport(WARNING,
3286  (errmsg("autovacuum not started because of misconfiguration"),
3287  errhint("Enable the \"track_counts\" option.")));
3288 }
3289 
3290 /*
3291  * IsAutoVacuum functions
3292  * Return whether this is either a launcher autovacuum process or a worker
3293  * process.
3294  */
3295 bool
3297 {
3298  return am_autovacuum_launcher;
3299 }
3300 
3301 bool
3303 {
3304  return am_autovacuum_worker;
3305 }
3306 
3307 
3308 /*
3309  * AutoVacuumShmemSize
3310  * Compute space needed for autovacuum-related shared memory
3311  */
3312 Size
3314 {
3315  Size size;
3316 
3317  /*
3318  * Need the fixed struct and the array of WorkerInfoData.
3319  */
3320  size = sizeof(AutoVacuumShmemStruct);
3321  size = MAXALIGN(size);
3323  sizeof(WorkerInfoData)));
3324  return size;
3325 }
3326 
3327 /*
3328  * AutoVacuumShmemInit
3329  * Allocate and initialize autovacuum-related shared memory
3330  */
3331 void
3333 {
3334  bool found;
3335 
3336  AutoVacuumShmem = (AutoVacuumShmemStruct *)
3337  ShmemInitStruct("AutoVacuum Data",
3339  &found);
3340 
3341  if (!IsUnderPostmaster)
3342  {
3343  WorkerInfo worker;
3344  int i;
3345 
3346  Assert(!found);
3347 
3348  AutoVacuumShmem->av_launcherpid = 0;
3349  dlist_init(&AutoVacuumShmem->av_freeWorkers);
3350  dlist_init(&AutoVacuumShmem->av_runningWorkers);
3351  AutoVacuumShmem->av_startingWorker = NULL;
3352  memset(AutoVacuumShmem->av_workItems, 0,
3353  sizeof(AutoVacuumWorkItem) * NUM_WORKITEMS);
3354 
3355  worker = (WorkerInfo) ((char *) AutoVacuumShmem +
3356  MAXALIGN(sizeof(AutoVacuumShmemStruct)));
3357 
3358  /* initialize the WorkerInfo free list */
3359  for (i = 0; i < autovacuum_max_workers; i++)
3360  dlist_push_head(&AutoVacuumShmem->av_freeWorkers,
3361  &worker[i].wi_links);
3362  }
3363  else
3364  Assert(found);
3365 }
3366 
3367 /*
3368  * autovac_refresh_stats
3369  * Refresh pgstats data for an autovacuum process
3370  *
3371  * Cause the next pgstats read operation to obtain fresh data, but throttle
3372  * such refreshing in the autovacuum launcher. This is mostly to avoid
3373  * rereading the pgstats files too many times in quick succession when there
3374  * are many databases.
3375  *
3376  * Note: we avoid throttling in the autovac worker, as it would be
3377  * counterproductive in the recheck logic.
3378  */
3379 static void
3381 {
3383  {
3384  static TimestampTz last_read = 0;
3385  TimestampTz current_time;
3386 
3387  current_time = GetCurrentTimestamp();
3388 
3389  if (!TimestampDifferenceExceeds(last_read, current_time,
3391  return;
3392 
3393  last_read = current_time;
3394  }
3395 
3397 }
AutoVacuumWorkItemType avw_type
Definition: autovacuum.c:256
BufferAccessStrategy GetAccessStrategy(BufferAccessStrategyType btype)
Definition: freelist.c:542
int autovacuum_work_mem
Definition: autovacuum.c:116
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Definition: sinval.c:176
static bool am_autovacuum_worker
Definition: autovacuum.c:141
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Definition: timeout.c:346
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Definition: pg_list.h:65
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Definition: lmgr.c:151
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Definition: autovacuum.c:3240
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struct avw_dbase avw_dbase
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Definition: vacuum.c:274
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Definition: mcxt.c:211
#define AllocSetContextCreate
Definition: memutils.h:170
MultiXactId adw_minmulti
Definition: autovacuum.c:174
volatile sig_atomic_t QueryCancelPending
Definition: globals.c:31
#define DEBUG1
Definition: elog.h:25
void table_close(Relation relation, LOCKMODE lockmode)
Definition: table.c:133
AutoVacuumWorkItemType
Definition: autovacuum.h:23
int MyProcPid
Definition: globals.c:40
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Definition: elog.c:1071
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Definition: autovacuum.c:264
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Definition: htup_details.h:655
#define MAX_AUTOVAC_SLEEPTIME
Definition: autovacuum.c:137
static void autovac_balance_cost(void)
Definition: autovacuum.c:1776
WorkerInfo av_startingWorker
Definition: autovacuum.c:288
sig_atomic_t av_signal[AutoVacNumSignals]
Definition: autovacuum.c:284
int vacuum_multixact_freeze_table_age
Definition: vacuum.c:64
static bool am_autovacuum_launcher
Definition: autovacuum.c:140
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Definition: hsearch.h:93
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Definition: hsearch.h:87
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Definition: latch.h:127
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Definition: autovacuum.c:114
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Definition: autovacuum.c:286
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Definition: autovacuum.c:120
static AutoVacOpts * extract_autovac_opts(HeapTuple tup, TupleDesc pg_class_desc)
Definition: autovacuum.c:2719
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Definition: pg_standby.c:42
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Definition: vacuum.c:1335
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Definition: miscinit.c:91
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Definition: hsearch.h:78
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Definition: autovacuum.c:432
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Definition: rel.h:482
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Definition: ilist.h:300
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Definition: elog.h:23
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Definition: win32_port.h:165
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Definition: lmgr.c:199
BackendType MyBackendType
Definition: miscinit.c:60
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Definition: timestamp.c:1583
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Definition: rel.h:292
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Definition: pgstat.c:3130
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Definition: autovacuum.c:1930
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Definition: pg_database.h:81
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Definition: win32_port.h:163
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Definition: proc.c:67
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Definition: timestamp.h:39
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Definition: autovacuum.c:234
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Definition: ilist.h:507
void AtEOXact_Buffers(bool isCommit)
Definition: bufmgr.c:2394
int adl_score
Definition: autovacuum.c:164
void SignalHandlerForConfigReload(SIGNAL_ARGS)
Definition: interrupt.c:56
char * pstrdup(const char *in)
Definition: mcxt.c:1186
void CommitTransactionCommand(void)
Definition: xact.c:2913
void ReleaseAuxProcessResources(bool isCommit)
Definition: resowner.c:879
TimestampTz wi_launchtime
Definition: autovacuum.c:226
static MemoryContext AutovacMemCxt
Definition: autovacuum.c:157
double wi_cost_delay
Definition: autovacuum.c:229
#define Min(x, y)
Definition: c.h:920
void ProcessProcSignalBarrier(void)
Definition: procsignal.c:429
Oid get_rel_namespace(Oid relid)
Definition: lsyscache.c:1815
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
static MultiXactId recentMulti
Definition: autovacuum.c:148
#define AccessShareLock
Definition: lockdefs.h:36
struct WorkerInfoData WorkerInfoData
Size entrysize
Definition: hsearch.h:73
struct avl_dbase avl_dbase
int autovacuum_multixact_freeze_max_age
Definition: autovacuum.c:125
void proc_exit(int code)
Definition: ipc.c:104
static void autovac_refresh_stats(void)
Definition: autovacuum.c:3380
#define MemSet(start, val, len)
Definition: c.h:971
PgStat_StatDBEntry * pgstat_fetch_stat_dbentry(Oid dbid)
Definition: pgstat.c:2479
#define SetProcessingMode(mode)
Definition: miscadmin.h:398
#define kill(pid, sig)
Definition: win32_port.h:426
void BaseInit(void)
Definition: postinit.c:548
dlist_node wi_links
Definition: autovacuum.c:222
uint32 BlockNumber
Definition: block.h:31
#define MIN_AUTOVAC_SLEEPTIME
Definition: autovacuum.c:136
#define lengthof(array)
Definition: c.h:668
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:907
#define SIGPIPE
Definition: win32_port.h:158
char * at_datname
Definition: autovacuum.c:199
#define SIGUSR2
Definition: win32_port.h:166
#define LOG
Definition: elog.h:26
#define STATS_READ_DELAY
Definition: autovacuum.c:133
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1338
NameData relname
Definition: pg_class.h:38
unsigned int Oid
Definition: postgres_ext.h:31
void SetLatch(Latch *latch)
Definition: latch.c:457
NON_EXEC_STATIC void AutoVacWorkerMain(int argc, char *argv[]) pg_attribute_noreturn()
Definition: autovacuum.c:1504
List * lappend_oid(List *list, Oid datum)
Definition: list.c:358
bool TimestampDifferenceExceeds(TimestampTz start_time, TimestampTz stop_time, int msec)
Definition: timestamp.c:1682
Snapshot GetTransactionSnapshot(void)
Definition: snapmgr.c:306
void ClosePostmasterPorts(bool am_syslogger)
Definition: postmaster.c:2546
#define OidIsValid(objectId)
Definition: c.h:644
void AbortOutOfAnyTransaction(void)
Definition: xact.c:4546
int freeze_table_age
Definition: vacuum.h:212
int autovacuum_vac_cost_limit
Definition: autovacuum.c:128
void FlushErrorState(void)
Definition: elog.c:1568
void ResetLatch(Latch *latch)
Definition: latch.c:540
#define PG_SETMASK(mask)
Definition: pqsignal.h:19
ResourceOwner AuxProcessResourceOwner
Definition: resowner.c:145
void StatementCancelHandler(SIGNAL_ARGS)
Definition: postgres.c:2857
void AtEOXact_Files(bool isCommit)
Definition: fd.c:2896
void autovac_init(void)
Definition: autovacuum.c:3282
Oid ar_toastrelid
Definition: autovacuum.c:181
AutoVacuumSignal
Definition: autovacuum.c:241
int WaitLatch(Latch *latch, int wakeEvents, long timeout, uint32 wait_event_info)
Definition: latch.c:365
double autovacuum_vac_ins_scale
Definition: autovacuum.c:121
MemoryContext PortalContext
Definition: mcxt.c:53
bool at_sharedrel
Definition: autovacuum.c:196
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1727
TempNamespaceStatus checkTempNamespaceStatus(Oid namespaceId)
Definition: namespace.c:3237
Datum brin_summarize_range(PG_FUNCTION_ARGS)
Definition: brin.c:860
#define RESUME_INTERRUPTS()
Definition: miscadmin.h:118
ErrorContextCallback * error_context_stack
Definition: elog.c:92
#define list_make1(x1)
Definition: pg_list.h:227
#define NAMEDATALEN
void set_ps_display(const char *activity)
Definition: ps_status.c:349
int freeze_table_age
Definition: rel.h:286
int at_vacuum_cost_limit
Definition: autovacuum.c:194
PgStat_Counter inserts_since_vacuum
Definition: pgstat.h:683
void pg_usleep(long microsec)
Definition: signal.c:53
static void HandleAutoVacLauncherInterrupts(void)
Definition: autovacuum.c:801
Definition: dynahash.c:209
char * at_relname
Definition: autovacuum.c:197
#define dlist_container(type, membername, ptr)
Definition: ilist.h:477
void AtEOXact_SMgr(void)
Definition: smgr.c:690
bool pgstat_track_counts
Definition: pgstat.c:125
void pfree(void *pointer)
Definition: mcxt.c:1056
#define dlist_tail_element(type, membername, lhead)
Definition: ilist.h:496
void disable_all_timeouts(bool keep_indicators)
Definition: timeout.c:598
#define FirstNormalTransactionId
Definition: transam.h:34
bool AutoVacuumingActive(void)
Definition: autovacuum.c:3228
#define ObjectIdGetDatum(X)
Definition: postgres.h:507
#define ERROR
Definition: elog.h:43
int AutovacuumLauncherPid
Definition: autovacuum.c:305
struct AutoVacuumWorkItem AutoVacuumWorkItem
int VacuumCostLimit
Definition: globals.c:140
int autovacuum_freeze_max_age
Definition: autovacuum.c:124
int StartAutoVacWorker(void)
Definition: autovacuum.c:1466
int freeze_min_age
Definition: vacuum.h:211
void * ShmemInitStruct(const char *name, Size size, bool *foundPtr)
Definition: shmem.c:392
int vacuum_multixact_freeze_min_age
Definition: vacuum.c:63
Definition: guc.h:75
Oid adl_datid
Definition: autovacuum.c:162
PgStat_Counter n_dead_tuples
Definition: pgstat.h:681
float8 vacuum_cost_delay
Definition: rel.h:291
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:192
bool is_wraparound
Definition: vacuum.h:217
char * get_database_name(Oid dbid)
Definition: dbcommands.c:2155
AutoVacuumWorkItem av_workItems[NUM_WORKITEMS]
Definition: autovacuum.c:289
#define DEBUG2
Definition: elog.h:24
void InitProcess(void)
Definition: proc.c:304
_stringlist * dblist
Definition: pg_regress.c:73
TimestampTz last_autovac_time
Definition: pgstat.h:636
double autovacuum_vac_cost_delay
Definition: autovacuum.c:127
char * get_namespace_name(Oid nspid)
Definition: lsyscache.c:3155
int analyze_threshold
Definition: rel.h:282
void on_shmem_exit(pg_on_exit_callback function, Datum arg)
Definition: ipc.c:361
void SetConfigOption(const char *name, const char *value, GucContext context, GucSource source)
Definition: guc.c:7684
HeapTuple heap_getnext(TableScanDesc sscan, ScanDirection direction)
Definition: heapam.c:1290
int autovacuum_vac_thresh
Definition: autovacuum.c:118
bool IsUnderPostmaster
Definition: globals.c:109
#define SIGHUP
Definition: win32_port.h:153
void performDeletion(const ObjectAddress *object, DropBehavior behavior, int flags)
Definition: dependency.c:316
static void autovac_report_workitem(AutoVacuumWorkItem *workitem, const char *nspname, const char *relname)
Definition: autovacuum.c:3188
static void perform_work_item(AutoVacuumWorkItem *workitem)
Definition: autovacuum.c:2613
#define MultiXactIdIsValid(multi)
Definition: multixact.h:27
sigset_t UnBlockSig
Definition: pqsignal.c:22
static void pgstat_report_wait_end(void)
Definition: pgstat.h:1386
#define FirstMultiXactId
Definition: multixact.h:24
MemoryContext CurrentMemoryContext
Definition: mcxt.c:38
static WorkerInfo MyWorkerInfo
Definition: autovacuum.c:302
static void relation_needs_vacanalyze(Oid relid, AutoVacOpts *relopts, Form_pg_class classForm, PgStat_StatTabEntry *tabentry, int effective_multixact_freeze_max_age, bool *dovacuum, bool *doanalyze, bool *wraparound)
Definition: autovacuum.c:2958
static void dlist_delete(dlist_node *node)
Definition: ilist.h:358
Datum Int64GetDatum(int64 X)
Definition: fmgr.c:1701
static dlist_head DatabaseList
Definition: autovacuum.c:298
bool IsAutoVacuumWorkerProcess(void)
Definition: autovacuum.c:3302
int synchronous_commit
Definition: xact.c:82
void pgstat_vacuum_stat(void)
Definition: pgstat.c:1046
int MultiXactMemberFreezeThreshold(void)
Definition: multixact.c:2819
int wi_cost_limit_base
Definition: autovacuum.c:231
char * adw_name
Definition: autovacuum.c:172
#define AssertArg(condition)
Definition: c.h:740
MemoryContext TopMemoryContext
Definition: mcxt.c:44
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:300
volatile sig_atomic_t ShutdownRequestPending
Definition: interrupt.c:27
VacOptTernaryValue index_cleanup
Definition: vacuum.h:221
Definition: guc.h:72
List * lappend(List *list, void *datum)
Definition: list.c:322
void SignalHandlerForShutdownRequest(SIGNAL_ARGS)
Definition: interrupt.c:104
static void avl_sigusr2_handler(SIGNAL_ARGS)
Definition: autovacuum.c:1413
#define SIG_IGN
Definition: win32_port.h:150
static void launcher_determine_sleep(bool canlaunch, bool recursing, struct timeval *nap)
Definition: autovacuum.c:854
TransactionId adw_frozenxid
Definition: autovacuum.c:173
#define DLIST_STATIC_INIT(name)
Definition: ilist.h:248
#define WARNING
Definition: elog.h:40
static int db_comparator(const void *a, const void *b)
Definition: autovacuum.c:1119
HeapTuple SearchSysCache1(int cacheId, Datum key1)
Definition: syscache.c:1116
float float4
Definition: c.h:490
void UnlockBuffers(void)
Definition: bufmgr.c:3645
#define MemoryContextResetAndDeleteChildren(ctx)
Definition: memutils.h:67
static void autovac_report_activity(autovac_table *tab)
Definition: autovacuum.c:3153
#define HASH_BLOBS
Definition: hsearch.h:88
char * at_nspname
Definition: autovacuum.c:198
int multixact_freeze_table_age
Definition: rel.h:289
Size mul_size(Size s1, Size s2)
Definition: shmem.c:515
int vacuum_threshold
Definition: rel.h:280
PgStat_StatDBEntry * adw_entry
Definition: autovacuum.c:175
HTAB * hash_create(const char *tabname, long nelem, HASHCTL *info, int flags)
Definition: dynahash.c:317
uintptr_t Datum
Definition: postgres.h:367
void ReleaseSysCache(HeapTuple tuple)
Definition: syscache.c:1164
struct @17::@18 av[32]
Size add_size(Size s1, Size s2)
Definition: shmem.c:498
Oid adw_datid
Definition: autovacuum.c:171
Oid MyDatabaseId
Definition: globals.c:85
int PostAuthDelay
Definition: postgres.c:102
double at_vacuum_cost_delay
Definition: autovacuum.c:193
struct autovac_table autovac_table
#define MAX_AUTOVAC_ACTIV_LEN
Size AutoVacuumShmemSize(void)
Definition: autovacuum.c:3313
BlockNumber avw_blockNumber
Definition: autovacuum.c:261
Size keysize
Definition: hsearch.h:72
static TransactionId recentXid
Definition: autovacuum.c:147
dlist_node * cur
Definition: ilist.h:161
void EmitErrorReport(void)
Definition: elog.c:1423
PgStat_Counter changes_since_analyze
Definition: pgstat.h:682
bytea * extractRelOptions(HeapTuple tuple, TupleDesc tupdesc, amoptions_function amoptions)
Definition: reloptions.c:1357
int autovacuum_max_workers
Definition: autovacuum.c:115
#define InvalidOid
Definition: postgres_ext.h:36
VacOptTernaryValue truncate
Definition: vacuum.h:223
static PgStat_StatTabEntry * get_pgstat_tabentry_relid(Oid relid, bool isshared, PgStat_StatDBEntry *shared, PgStat_StatDBEntry *dbentry)
Definition: autovacuum.c:2745
#define TimestampTzPlusMilliseconds(tz, ms)
Definition: timestamp.h:56
static void dlist_init(dlist_head *head)
Definition: ilist.h:278
double autovacuum_vac_scale
Definition: autovacuum.c:119
VacuumParams at_params
Definition: autovacuum.c:192
#define ereport(elevel,...)
Definition: elog.h:144
void InitPostgres(const char *in_dbname, Oid dboid, const char *username, Oid useroid, char *out_dbname, bool override_allow_connections)
Definition: postinit.c:590
#define BlockNumberIsValid(blockNumber)
Definition: block.h:70
pqsigfunc pqsignal(int signum, pqsigfunc handler)
Definition: signal.c:170
static volatile sig_atomic_t got_SIGUSR2
Definition: autovacuum.c:144
float8 analyze_scale_factor
Definition: rel.h:294
TransactionId MultiXactId
Definition: c.h:523
bool IsAutoVacuumLauncherProcess(void)
Definition: autovacuum.c:3296
#define PG_CATCH()
Definition: elog.h:305
#define Max(x, y)
Definition: c.h:914
int freeze_max_age
Definition: rel.h:285
int vacuum_cost_limit
Definition: rel.h:283
#define SIG_DFL
Definition: win32_port.h:148
#define HeapTupleIsValid(tuple)
Definition: htup.h:78
#define SIGNAL_ARGS
Definition: c.h:1296
#define Assert(condition)
Definition: c.h:738
#define lfirst(lc)
Definition: pg_list.h:190
#define PERFORM_DELETION_QUIETLY
Definition: dependency.h:136
bool enabled
Definition: rel.h:279
volatile sig_atomic_t ProcSignalBarrierPending
Definition: globals.c:35
int multixact_freeze_min_age
Definition: rel.h:287
void StartTransactionCommand(void)
Definition: xact.c:2812
static bool dlist_is_empty(dlist_head *head)
Definition: ilist.h:289
void pgstat_clear_snapshot(void)
Definition: pgstat.c:5837
size_t Size
Definition: c.h:466
char * dbname
Definition: streamutil.c:50
static void FreeWorkerInfo(int code, Datum arg)
Definition: autovacuum.c:1711
int nworkers
Definition: vacuum.h:231
static AutoVacuumShmemStruct * AutoVacuumShmem
Definition: autovacuum.c:292
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1123
int vacuum_freeze_min_age
Definition: vacuum.c:61
void AbortBufferIO(void)
Definition: bufmgr.c:4123
#define MAXALIGN(LEN)
Definition: c.h:691
int log_min_duration
Definition: vacuum.h:218
bool MultiXactIdPrecedes(MultiXactId multi1, MultiXactId multi2)
Definition: multixact.c:3142
void * hash_seq_search(HASH_SEQ_STATUS *status)
Definition: dynahash.c:1390
void AutoVacWorkerFailed(void)
Definition: autovacuum.c:1406
void hash_seq_init(HASH_SEQ_STATUS *status, HTAB *hashp)
Definition: dynahash.c:1380
int vacuum_freeze_table_age
Definition: vacuum.c:62
int log_min_duration
Definition: rel.h:290
sigjmp_buf * PG_exception_stack
Definition: elog.c:94
static List * get_database_list(void)
Definition: autovacuum.c:1864
#define CharGetDatum(X)
Definition: postgres.h:416
int StartAutoVacLauncher(void)
dlist_node adl_node
Definition: autovacuum.c:165
static void dlist_move_head(dlist_head *head, dlist_node *node)
Definition: ilist.h:385
static TransactionId ReadNewTransactionId(void)
Definition: transam.h:244
static void rebuild_database_list(Oid newdb)
Definition: autovacuum.c:938
int Log_autovacuum_min_duration
Definition: autovacuum.c:130
static void table_endscan(TableScanDesc scan)
Definition: tableam.h:862
static pid_t AutoVacPID
Definition: postmaster.c:255
FormData_pg_class * Form_pg_class
Definition: pg_class.h:153
#define SearchSysCacheCopy1(cacheId, key1)
Definition: syscache.h:174
AutoVacOpts ar_reloptions
Definition: autovacuum.c:184
#define AccessExclusiveLock
Definition: lockdefs.h:45
static void autovacuum_do_vac_analyze(autovac_table *tab, BufferAccessStrategy bstrategy)
Definition: autovacuum.c:3124
void SetCurrentStatementStartTimestamp(void)
Definition: xact.c:817
static void AutoVacLauncherShutdown(void)
Definition: autovacuum.c:316
void * palloc(Size size)
Definition: mcxt.c:949
int errmsg(const char *fmt,...)
Definition: elog.c:824
double VacuumCostDelay
Definition: globals.c:141
int vacuum_ins_threshold
Definition: rel.h:281
static dlist_node * dlist_pop_head_node(dlist_head *head)
Definition: ilist.h:368
#define HOLD_INTERRUPTS()
Definition: miscadmin.h:116
#define elog(elevel,...)
Definition: elog.h:214
static MemoryContext DatabaseListCxt
Definition: autovacuum.c:299
volatile sig_atomic_t ConfigReloadPending
Definition: interrupt.c:26
int i
void FloatExceptionHandler(SIGNAL_ARGS)
Definition: postgres.c:2878
int options
Definition: vacuum.h:210
#define errcontext
Definition: elog.h:185
#define NameStr(name)
Definition: c.h:615
struct av_relation av_relation
void ScanKeyInit(ScanKey entry, AttrNumber attributeNumber, StrategyNumber strategy, RegProcedure procedure, Datum argument)
Definition: scankey.c:76
int multixact_freeze_max_age
Definition: rel.h:288
void * arg
void AutoVacuumUpdateDelay(void)
Definition: autovacuum.c:1760
struct Latch * MyLatch
Definition: globals.c:54
Definition: c.h:555
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:99
PGPROC * wi_proc
Definition: autovacuum.c:225
static void launch_worker(TimestampTz now)
Definition: autovacuum.c:1354
float8 vacuum_ins_scale_factor
Definition: rel.h:293
void SendPostmasterSignal(PMSignalReason reason)
Definition: pmsignal.c:146
static autovac_table * table_recheck_autovac(Oid relid, HTAB *table_toast_map, TupleDesc pg_class_desc, int effective_multixact_freeze_max_age)
Definition: autovacuum.c:2772
void init_ps_display(const char *fixed_part)
Definition: ps_status.c:258
void LWLockReleaseAll(void)
Definition: lwlock.c:1826
#define qsort(a, b, c, d)
Definition: port.h:479
void procsignal_sigusr1_handler(SIGNAL_ARGS)
Definition: procsignal.c:533
void AtEOXact_HashTables(bool isCommit)
Definition: dynahash.c:1835
void AutoVacuumShmemInit(void)
Definition: autovacuum.c:3332
dlist_head av_runningWorkers
Definition: autovacuum.c:287
void TimestampDifference(TimestampTz start_time, TimestampTz stop_time, long *secs, int *microsecs)
Definition: timestamp.c:1657
#define TransactionIdIsNormal(xid)
Definition: transam.h:42
#define PG_TRY()
Definition: elog.h:295
Relation table_open(Oid relationId, LOCKMODE lockmode)
Definition: table.c:39
#define PERFORM_DELETION_SKIP_EXTENSIONS
Definition: dependency.h:138
Definition: proc.h:95
bool ar_hasrelopts
Definition: autovacuum.c:183
Definition: pg_list.h:50
char * get_rel_name(Oid relid)
Definition: lsyscache.c:1791
#define PointerIsValid(pointer)
Definition: c.h:632
#define snprintf
Definition: port.h:193
int pid
Definition: proc.h:109
static int default_multixact_freeze_table_age
Definition: autovacuum.c:154
#define WL_LATCH_SET
Definition: latch.h:124
void pgstat_report_autovac(Oid dboid)
Definition: pgstat.c:1435
void quickdie(SIGNAL_ARGS)
Definition: postgres.c:2759
static Oid do_start_worker(void)
Definition: autovacuum.c:1139
int multixact_freeze_min_age
Definition: vacuum.h:213
#define dlist_reverse_foreach(iter, lhead)
Definition: ilist.h:538
static int default_freeze_min_age
Definition: autovacuum.c:151
Datum now(PG_FUNCTION_ARGS)
Definition: timestamp.c:1547
RangeVar * makeRangeVar(char *schemaname, char *relname, int location)
Definition: makefuncs.c:420
#define die(msg)
Definition: pg_test_fsync.c:96
#define DirectFunctionCall2(func, arg1, arg2)
Definition: fmgr.h:621
#define PG_END_TRY()
Definition: elog.h:320
#define BTEqualStrategyNumber
Definition: stratnum.h:31
bool at_dobalance
Definition: autovacuum.c:195
#define lfirst_oid(lc)
Definition: pg_list.h:192
#define WL_EXIT_ON_PM_DEATH
Definition: latch.h:129
#define PERFORM_DELETION_INTERNAL
Definition: dependency.h:134
int autovacuum_anl_thresh
Definition: autovacuum.c:122
MultiXactId ReadNextMultiXactId(void)
Definition: multixact.c:723
#define NON_EXEC_STATIC
Definition: c.h:1314