Line data Source code
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) 1996-2019, 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"
86 : #include "postmaster/fork_process.h"
87 : #include "postmaster/postmaster.h"
88 : #include "storage/bufmgr.h"
89 : #include "storage/ipc.h"
90 : #include "storage/latch.h"
91 : #include "storage/lmgr.h"
92 : #include "storage/pmsignal.h"
93 : #include "storage/proc.h"
94 : #include "storage/procsignal.h"
95 : #include "storage/sinvaladt.h"
96 : #include "storage/smgr.h"
97 : #include "tcop/tcopprot.h"
98 : #include "utils/fmgroids.h"
99 : #include "utils/fmgrprotos.h"
100 : #include "utils/lsyscache.h"
101 : #include "utils/memutils.h"
102 : #include "utils/ps_status.h"
103 : #include "utils/rel.h"
104 : #include "utils/snapmgr.h"
105 : #include "utils/syscache.h"
106 : #include "utils/timeout.h"
107 : #include "utils/timestamp.h"
108 :
109 :
110 : /*
111 : * GUC parameters
112 : */
113 : bool autovacuum_start_daemon = false;
114 : int autovacuum_max_workers;
115 : int autovacuum_work_mem = -1;
116 : int autovacuum_naptime;
117 : int autovacuum_vac_thresh;
118 : double autovacuum_vac_scale;
119 : int autovacuum_anl_thresh;
120 : double autovacuum_anl_scale;
121 : int autovacuum_freeze_max_age;
122 : int autovacuum_multixact_freeze_max_age;
123 :
124 : double autovacuum_vac_cost_delay;
125 : int autovacuum_vac_cost_limit;
126 :
127 : int Log_autovacuum_min_duration = -1;
128 :
129 : /* how long to keep pgstat data in the launcher, in milliseconds */
130 : #define STATS_READ_DELAY 1000
131 :
132 : /* the minimum allowed time between two awakenings of the launcher */
133 : #define MIN_AUTOVAC_SLEEPTIME 100.0 /* milliseconds */
134 : #define MAX_AUTOVAC_SLEEPTIME 300 /* seconds */
135 :
136 : /* Flags to tell if we are in an autovacuum process */
137 : static bool am_autovacuum_launcher = false;
138 : static bool am_autovacuum_worker = false;
139 :
140 : /* Flags set by signal handlers */
141 : static volatile sig_atomic_t got_SIGHUP = false;
142 : static volatile sig_atomic_t got_SIGUSR2 = false;
143 : static volatile sig_atomic_t got_SIGTERM = false;
144 :
145 : /* Comparison points for determining whether freeze_max_age is exceeded */
146 : static TransactionId recentXid;
147 : static MultiXactId recentMulti;
148 :
149 : /* Default freeze ages to use for autovacuum (varies by database) */
150 : static int default_freeze_min_age;
151 : static int default_freeze_table_age;
152 : static int default_multixact_freeze_min_age;
153 : static int default_multixact_freeze_table_age;
154 :
155 : /* Memory context for long-lived data */
156 : static MemoryContext AutovacMemCxt;
157 :
158 : /* struct to keep track of databases in launcher */
159 : typedef struct avl_dbase
160 : {
161 : Oid adl_datid; /* hash key -- must be first */
162 : TimestampTz adl_next_worker;
163 : int adl_score;
164 : dlist_node adl_node;
165 : } avl_dbase;
166 :
167 : /* struct to keep track of databases in worker */
168 : typedef struct avw_dbase
169 : {
170 : Oid adw_datid;
171 : char *adw_name;
172 : TransactionId adw_frozenxid;
173 : MultiXactId adw_minmulti;
174 : PgStat_StatDBEntry *adw_entry;
175 : } avw_dbase;
176 :
177 : /* struct to keep track of tables to vacuum and/or analyze, in 1st pass */
178 : typedef struct av_relation
179 : {
180 : Oid ar_toastrelid; /* hash key - must be first */
181 : Oid ar_relid;
182 : bool ar_hasrelopts;
183 : AutoVacOpts ar_reloptions; /* copy of AutoVacOpts from the main table's
184 : * reloptions, or NULL if none */
185 : } av_relation;
186 :
187 : /* struct to keep track of tables to vacuum and/or analyze, after rechecking */
188 : typedef struct autovac_table
189 : {
190 : Oid at_relid;
191 : VacuumParams at_params;
192 : double at_vacuum_cost_delay;
193 : int at_vacuum_cost_limit;
194 : bool at_dobalance;
195 : bool at_sharedrel;
196 : char *at_relname;
197 : char *at_nspname;
198 : char *at_datname;
199 : } autovac_table;
200 :
201 : /*-------------
202 : * This struct holds information about a single worker's whereabouts. We keep
203 : * an array of these in shared memory, sized according to
204 : * autovacuum_max_workers.
205 : *
206 : * wi_links entry into free list or running list
207 : * wi_dboid OID of the database this worker is supposed to work on
208 : * wi_tableoid OID of the table currently being vacuumed, if any
209 : * wi_sharedrel flag indicating whether table is marked relisshared
210 : * wi_proc pointer to PGPROC of the running worker, NULL if not started
211 : * wi_launchtime Time at which this worker was launched
212 : * wi_cost_* Vacuum cost-based delay parameters current in this worker
213 : *
214 : * All fields are protected by AutovacuumLock, except for wi_tableoid and
215 : * wi_sharedrel which are protected by AutovacuumScheduleLock (note these
216 : * two fields are read-only for everyone except that worker itself).
217 : *-------------
218 : */
219 : typedef struct WorkerInfoData
220 : {
221 : dlist_node wi_links;
222 : Oid wi_dboid;
223 : Oid wi_tableoid;
224 : PGPROC *wi_proc;
225 : TimestampTz wi_launchtime;
226 : bool wi_dobalance;
227 : bool wi_sharedrel;
228 : double wi_cost_delay;
229 : int wi_cost_limit;
230 : int wi_cost_limit_base;
231 : } WorkerInfoData;
232 :
233 : typedef struct WorkerInfoData *WorkerInfo;
234 :
235 : /*
236 : * Possible signals received by the launcher from remote processes. These are
237 : * stored atomically in shared memory so that other processes can set them
238 : * without locking.
239 : */
240 : typedef enum
241 : {
242 : AutoVacForkFailed, /* failed trying to start a worker */
243 : AutoVacRebalance, /* rebalance the cost limits */
244 : AutoVacNumSignals /* must be last */
245 : } AutoVacuumSignal;
246 :
247 : /*
248 : * Autovacuum workitem array, stored in AutoVacuumShmem->av_workItems. This
249 : * list is mostly protected by AutovacuumLock, except that if an item is
250 : * marked 'active' other processes must not modify the work-identifying
251 : * members.
252 : */
253 : typedef struct AutoVacuumWorkItem
254 : {
255 : AutoVacuumWorkItemType avw_type;
256 : bool avw_used; /* below data is valid */
257 : bool avw_active; /* being processed */
258 : Oid avw_database;
259 : Oid avw_relation;
260 : BlockNumber avw_blockNumber;
261 : } AutoVacuumWorkItem;
262 :
263 : #define NUM_WORKITEMS 256
264 :
265 : /*-------------
266 : * The main autovacuum shmem struct. On shared memory we store this main
267 : * struct and the array of WorkerInfo structs. This struct keeps:
268 : *
269 : * av_signal set by other processes to indicate various conditions
270 : * av_launcherpid the PID of the autovacuum launcher
271 : * av_freeWorkers the WorkerInfo freelist
272 : * av_runningWorkers the WorkerInfo non-free queue
273 : * av_startingWorker pointer to WorkerInfo currently being started (cleared by
274 : * the worker itself as soon as it's up and running)
275 : * av_workItems work item array
276 : *
277 : * This struct is protected by AutovacuumLock, except for av_signal and parts
278 : * of the worker list (see above).
279 : *-------------
280 : */
281 : typedef struct
282 : {
283 : sig_atomic_t av_signal[AutoVacNumSignals];
284 : pid_t av_launcherpid;
285 : dlist_head av_freeWorkers;
286 : dlist_head av_runningWorkers;
287 : WorkerInfo av_startingWorker;
288 : AutoVacuumWorkItem av_workItems[NUM_WORKITEMS];
289 : } AutoVacuumShmemStruct;
290 :
291 : static AutoVacuumShmemStruct *AutoVacuumShmem;
292 :
293 : /*
294 : * the database list (of avl_dbase elements) in the launcher, and the context
295 : * that contains it
296 : */
297 : static dlist_head DatabaseList = DLIST_STATIC_INIT(DatabaseList);
298 : static MemoryContext DatabaseListCxt = NULL;
299 :
300 : /* Pointer to my own WorkerInfo, valid on each worker */
301 : static WorkerInfo MyWorkerInfo = NULL;
302 :
303 : /* PID of launcher, valid only in worker while shutting down */
304 : int AutovacuumLauncherPid = 0;
305 :
306 : #ifdef EXEC_BACKEND
307 : static pid_t avlauncher_forkexec(void);
308 : static pid_t avworker_forkexec(void);
309 : #endif
310 : NON_EXEC_STATIC void AutoVacWorkerMain(int argc, char *argv[]) pg_attribute_noreturn();
311 : NON_EXEC_STATIC void AutoVacLauncherMain(int argc, char *argv[]) pg_attribute_noreturn();
312 :
313 : static Oid do_start_worker(void);
314 : static void launcher_determine_sleep(bool canlaunch, bool recursing,
315 : struct timeval *nap);
316 : static void launch_worker(TimestampTz now);
317 : static List *get_database_list(void);
318 : static void rebuild_database_list(Oid newdb);
319 : static int db_comparator(const void *a, const void *b);
320 : static void autovac_balance_cost(void);
321 :
322 : static void do_autovacuum(void);
323 : static void FreeWorkerInfo(int code, Datum arg);
324 :
325 : static autovac_table *table_recheck_autovac(Oid relid, HTAB *table_toast_map,
326 : TupleDesc pg_class_desc,
327 : int effective_multixact_freeze_max_age);
328 : static void relation_needs_vacanalyze(Oid relid, AutoVacOpts *relopts,
329 : Form_pg_class classForm,
330 : PgStat_StatTabEntry *tabentry,
331 : int effective_multixact_freeze_max_age,
332 : bool *dovacuum, bool *doanalyze, bool *wraparound);
333 :
334 : static void autovacuum_do_vac_analyze(autovac_table *tab,
335 : BufferAccessStrategy bstrategy);
336 : static AutoVacOpts *extract_autovac_opts(HeapTuple tup,
337 : TupleDesc pg_class_desc);
338 : static PgStat_StatTabEntry *get_pgstat_tabentry_relid(Oid relid, bool isshared,
339 : PgStat_StatDBEntry *shared,
340 : PgStat_StatDBEntry *dbentry);
341 : static void perform_work_item(AutoVacuumWorkItem *workitem);
342 : static void autovac_report_activity(autovac_table *tab);
343 : static void autovac_report_workitem(AutoVacuumWorkItem *workitem,
344 : const char *nspname, const char *relname);
345 : static void av_sighup_handler(SIGNAL_ARGS);
346 : static void avl_sigusr2_handler(SIGNAL_ARGS);
347 : static void avl_sigterm_handler(SIGNAL_ARGS);
348 : static void autovac_refresh_stats(void);
349 :
350 :
351 :
352 : /********************************************************************
353 : * AUTOVACUUM LAUNCHER CODE
354 : ********************************************************************/
355 :
356 : #ifdef EXEC_BACKEND
357 : /*
358 : * forkexec routine for the autovacuum launcher process.
359 : *
360 : * Format up the arglist, then fork and exec.
361 : */
362 : static pid_t
363 : avlauncher_forkexec(void)
364 : {
365 : char *av[10];
366 : int ac = 0;
367 :
368 : av[ac++] = "postgres";
369 : av[ac++] = "--forkavlauncher";
370 : av[ac++] = NULL; /* filled in by postmaster_forkexec */
371 : av[ac] = NULL;
372 :
373 : Assert(ac < lengthof(av));
374 :
375 : return postmaster_forkexec(ac, av);
376 : }
377 :
378 : /*
379 : * We need this set from the outside, before InitProcess is called
380 : */
381 : void
382 : AutovacuumLauncherIAm(void)
383 : {
384 : am_autovacuum_launcher = true;
385 : }
386 : #endif
387 :
388 : /*
389 : * Main entry point for autovacuum launcher process, to be called from the
390 : * postmaster.
391 : */
392 : int
393 480 : StartAutoVacLauncher(void)
394 : {
395 : pid_t AutoVacPID;
396 :
397 : #ifdef EXEC_BACKEND
398 : switch ((AutoVacPID = avlauncher_forkexec()))
399 : #else
400 480 : switch ((AutoVacPID = fork_process()))
401 : #endif
402 : {
403 : case -1:
404 0 : ereport(LOG,
405 : (errmsg("could not fork autovacuum launcher process: %m")));
406 0 : return 0;
407 :
408 : #ifndef EXEC_BACKEND
409 : case 0:
410 : /* in postmaster child ... */
411 346 : InitPostmasterChild();
412 :
413 : /* Close the postmaster's sockets */
414 346 : ClosePostmasterPorts(false);
415 :
416 346 : AutoVacLauncherMain(0, NULL);
417 : break;
418 : #endif
419 : default:
420 480 : return (int) AutoVacPID;
421 : }
422 :
423 : /* shouldn't get here */
424 : return 0;
425 : }
426 :
427 : /*
428 : * Main loop for the autovacuum launcher process.
429 : */
430 : NON_EXEC_STATIC void
431 346 : AutoVacLauncherMain(int argc, char *argv[])
432 : {
433 : sigjmp_buf local_sigjmp_buf;
434 :
435 346 : am_autovacuum_launcher = true;
436 :
437 : /* Identify myself via ps */
438 346 : init_ps_display(pgstat_get_backend_desc(B_AUTOVAC_LAUNCHER), "", "", "");
439 :
440 346 : ereport(DEBUG1,
441 : (errmsg("autovacuum launcher started")));
442 :
443 346 : if (PostAuthDelay)
444 0 : pg_usleep(PostAuthDelay * 1000000L);
445 :
446 346 : SetProcessingMode(InitProcessing);
447 :
448 : /*
449 : * Set up signal handlers. We operate on databases much like a regular
450 : * backend, so we use the same signal handling. See equivalent code in
451 : * tcop/postgres.c.
452 : */
453 346 : pqsignal(SIGHUP, av_sighup_handler);
454 346 : pqsignal(SIGINT, StatementCancelHandler);
455 346 : pqsignal(SIGTERM, avl_sigterm_handler);
456 :
457 346 : pqsignal(SIGQUIT, quickdie);
458 346 : InitializeTimeouts(); /* establishes SIGALRM handler */
459 :
460 346 : pqsignal(SIGPIPE, SIG_IGN);
461 346 : pqsignal(SIGUSR1, procsignal_sigusr1_handler);
462 346 : pqsignal(SIGUSR2, avl_sigusr2_handler);
463 346 : pqsignal(SIGFPE, FloatExceptionHandler);
464 346 : pqsignal(SIGCHLD, SIG_DFL);
465 :
466 : /* Early initialization */
467 346 : BaseInit();
468 :
469 : /*
470 : * Create a per-backend PGPROC struct in shared memory, except in the
471 : * EXEC_BACKEND case where this was done in SubPostmasterMain. We must do
472 : * this before we can use LWLocks (and in the EXEC_BACKEND case we already
473 : * had to do some stuff with LWLocks).
474 : */
475 : #ifndef EXEC_BACKEND
476 346 : InitProcess();
477 : #endif
478 :
479 346 : InitPostgres(NULL, InvalidOid, NULL, InvalidOid, NULL, false);
480 :
481 346 : SetProcessingMode(NormalProcessing);
482 :
483 : /*
484 : * Create a memory context that we will do all our work in. We do this so
485 : * that we can reset the context during error recovery and thereby avoid
486 : * possible memory leaks.
487 : */
488 346 : AutovacMemCxt = AllocSetContextCreate(TopMemoryContext,
489 : "Autovacuum Launcher",
490 : ALLOCSET_DEFAULT_SIZES);
491 346 : MemoryContextSwitchTo(AutovacMemCxt);
492 :
493 : /*
494 : * If an exception is encountered, processing resumes here.
495 : *
496 : * This code is a stripped down version of PostgresMain error recovery.
497 : */
498 346 : if (sigsetjmp(local_sigjmp_buf, 1) != 0)
499 : {
500 : /* since not using PG_TRY, must reset error stack by hand */
501 0 : error_context_stack = NULL;
502 :
503 : /* Prevents interrupts while cleaning up */
504 0 : HOLD_INTERRUPTS();
505 :
506 : /* Forget any pending QueryCancel or timeout request */
507 0 : disable_all_timeouts(false);
508 0 : QueryCancelPending = false; /* second to avoid race condition */
509 :
510 : /* Report the error to the server log */
511 0 : EmitErrorReport();
512 :
513 : /* Abort the current transaction in order to recover */
514 0 : AbortCurrentTransaction();
515 :
516 : /*
517 : * Release any other resources, for the case where we were not in a
518 : * transaction.
519 : */
520 0 : LWLockReleaseAll();
521 0 : pgstat_report_wait_end();
522 0 : AbortBufferIO();
523 0 : UnlockBuffers();
524 : /* this is probably dead code, but let's be safe: */
525 0 : if (AuxProcessResourceOwner)
526 0 : ReleaseAuxProcessResources(false);
527 0 : AtEOXact_Buffers(false);
528 0 : AtEOXact_SMgr();
529 0 : AtEOXact_Files(false);
530 0 : AtEOXact_HashTables(false);
531 :
532 : /*
533 : * Now return to normal top-level context and clear ErrorContext for
534 : * next time.
535 : */
536 0 : MemoryContextSwitchTo(AutovacMemCxt);
537 0 : FlushErrorState();
538 :
539 : /* Flush any leaked data in the top-level context */
540 0 : MemoryContextResetAndDeleteChildren(AutovacMemCxt);
541 :
542 : /* don't leave dangling pointers to freed memory */
543 0 : DatabaseListCxt = NULL;
544 0 : dlist_init(&DatabaseList);
545 :
546 : /*
547 : * Make sure pgstat also considers our stat data as gone. Note: we
548 : * mustn't use autovac_refresh_stats here.
549 : */
550 0 : pgstat_clear_snapshot();
551 :
552 : /* Now we can allow interrupts again */
553 0 : RESUME_INTERRUPTS();
554 :
555 : /* if in shutdown mode, no need for anything further; just go away */
556 0 : if (got_SIGTERM)
557 0 : goto shutdown;
558 :
559 : /*
560 : * Sleep at least 1 second after any error. We don't want to be
561 : * filling the error logs as fast as we can.
562 : */
563 0 : pg_usleep(1000000L);
564 : }
565 :
566 : /* We can now handle ereport(ERROR) */
567 346 : PG_exception_stack = &local_sigjmp_buf;
568 :
569 : /* must unblock signals before calling rebuild_database_list */
570 346 : PG_SETMASK(&UnBlockSig);
571 :
572 : /*
573 : * Set always-secure search path. Launcher doesn't connect to a database,
574 : * so this has no effect.
575 : */
576 346 : SetConfigOption("search_path", "", PGC_SUSET, PGC_S_OVERRIDE);
577 :
578 : /*
579 : * Force zero_damaged_pages OFF in the autovac process, even if it is set
580 : * in postgresql.conf. We don't really want such a dangerous option being
581 : * applied non-interactively.
582 : */
583 346 : SetConfigOption("zero_damaged_pages", "false", PGC_SUSET, PGC_S_OVERRIDE);
584 :
585 : /*
586 : * Force settable timeouts off to avoid letting these settings prevent
587 : * regular maintenance from being executed.
588 : */
589 346 : SetConfigOption("statement_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
590 346 : SetConfigOption("lock_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
591 346 : SetConfigOption("idle_in_transaction_session_timeout", "0",
592 : PGC_SUSET, PGC_S_OVERRIDE);
593 :
594 : /*
595 : * Force default_transaction_isolation to READ COMMITTED. We don't want
596 : * to pay the overhead of serializable mode, nor add any risk of causing
597 : * deadlocks or delaying other transactions.
598 : */
599 346 : SetConfigOption("default_transaction_isolation", "read committed",
600 : PGC_SUSET, PGC_S_OVERRIDE);
601 :
602 : /*
603 : * In emergency mode, just start a worker (unless shutdown was requested)
604 : * and go away.
605 : */
606 346 : if (!AutoVacuumingActive())
607 : {
608 0 : if (!got_SIGTERM)
609 0 : do_start_worker();
610 0 : proc_exit(0); /* done */
611 : }
612 :
613 346 : AutoVacuumShmem->av_launcherpid = MyProcPid;
614 :
615 : /*
616 : * Create the initial database list. The invariant we want this list to
617 : * keep is that it's ordered by decreasing next_time. As soon as an entry
618 : * is updated to a higher time, it will be moved to the front (which is
619 : * correct because the only operation is to add autovacuum_naptime to the
620 : * entry, and time always increases).
621 : */
622 346 : rebuild_database_list(InvalidOid);
623 :
624 : /* loop until shutdown request */
625 1946 : while (!got_SIGTERM)
626 : {
627 : struct timeval nap;
628 1600 : TimestampTz current_time = 0;
629 : bool can_launch;
630 :
631 : /*
632 : * This loop is a bit different from the normal use of WaitLatch,
633 : * because we'd like to sleep before the first launch of a child
634 : * process. So it's WaitLatch, then ResetLatch, then check for
635 : * wakening conditions.
636 : */
637 :
638 3200 : launcher_determine_sleep(!dlist_is_empty(&AutoVacuumShmem->av_freeWorkers),
639 1600 : false, &nap);
640 :
641 : /*
642 : * Wait until naptime expires or we get some type of signal (all the
643 : * signal handlers will wake us by calling SetLatch).
644 : */
645 1600 : (void) WaitLatch(MyLatch,
646 : WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
647 1600 : (nap.tv_sec * 1000L) + (nap.tv_usec / 1000L),
648 : WAIT_EVENT_AUTOVACUUM_MAIN);
649 :
650 1596 : ResetLatch(MyLatch);
651 :
652 : /* Process sinval catchup interrupts that happened while sleeping */
653 1596 : ProcessCatchupInterrupt();
654 :
655 : /* the normal shutdown case */
656 1596 : if (got_SIGTERM)
657 684 : break;
658 :
659 1254 : if (got_SIGHUP)
660 : {
661 8 : got_SIGHUP = false;
662 8 : ProcessConfigFile(PGC_SIGHUP);
663 :
664 : /* shutdown requested in config file? */
665 8 : if (!AutoVacuumingActive())
666 0 : break;
667 :
668 : /* rebalance in case the default cost parameters changed */
669 8 : LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
670 8 : autovac_balance_cost();
671 8 : LWLockRelease(AutovacuumLock);
672 :
673 : /* rebuild the list in case the naptime changed */
674 8 : rebuild_database_list(InvalidOid);
675 : }
676 :
677 : /*
678 : * a worker finished, or postmaster signalled failure to start a
679 : * worker
680 : */
681 1254 : if (got_SIGUSR2)
682 : {
683 102 : got_SIGUSR2 = false;
684 :
685 : /* rebalance cost limits, if needed */
686 102 : if (AutoVacuumShmem->av_signal[AutoVacRebalance])
687 : {
688 50 : LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
689 50 : AutoVacuumShmem->av_signal[AutoVacRebalance] = false;
690 50 : autovac_balance_cost();
691 50 : LWLockRelease(AutovacuumLock);
692 : }
693 :
694 102 : if (AutoVacuumShmem->av_signal[AutoVacForkFailed])
695 : {
696 : /*
697 : * If the postmaster failed to start a new worker, we sleep
698 : * for a little while and resend the signal. The new worker's
699 : * state is still in memory, so this is sufficient. After
700 : * that, we restart the main loop.
701 : *
702 : * XXX should we put a limit to the number of times we retry?
703 : * I don't think it makes much sense, because a future start
704 : * of a worker will continue to fail in the same way.
705 : */
706 0 : AutoVacuumShmem->av_signal[AutoVacForkFailed] = false;
707 0 : pg_usleep(1000000L); /* 1s */
708 0 : SendPostmasterSignal(PMSIGNAL_START_AUTOVAC_WORKER);
709 0 : continue;
710 : }
711 : }
712 :
713 : /*
714 : * There are some conditions that we need to check before trying to
715 : * start a worker. First, we need to make sure that there is a worker
716 : * slot available. Second, we need to make sure that no other worker
717 : * failed while starting up.
718 : */
719 :
720 1254 : current_time = GetCurrentTimestamp();
721 1254 : LWLockAcquire(AutovacuumLock, LW_SHARED);
722 :
723 1254 : can_launch = !dlist_is_empty(&AutoVacuumShmem->av_freeWorkers);
724 :
725 1254 : if (AutoVacuumShmem->av_startingWorker != NULL)
726 : {
727 : int waittime;
728 0 : WorkerInfo worker = AutoVacuumShmem->av_startingWorker;
729 :
730 : /*
731 : * We can't launch another worker when another one is still
732 : * starting up (or failed while doing so), so just sleep for a bit
733 : * more; that worker will wake us up again as soon as it's ready.
734 : * We will only wait autovacuum_naptime seconds (up to a maximum
735 : * of 60 seconds) for this to happen however. Note that failure
736 : * to connect to a particular database is not a problem here,
737 : * because the worker removes itself from the startingWorker
738 : * pointer before trying to connect. Problems detected by the
739 : * postmaster (like fork() failure) are also reported and handled
740 : * differently. The only problems that may cause this code to
741 : * fire are errors in the earlier sections of AutoVacWorkerMain,
742 : * before the worker removes the WorkerInfo from the
743 : * startingWorker pointer.
744 : */
745 0 : waittime = Min(autovacuum_naptime, 60) * 1000;
746 0 : if (TimestampDifferenceExceeds(worker->wi_launchtime, current_time,
747 : waittime))
748 : {
749 0 : LWLockRelease(AutovacuumLock);
750 0 : LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
751 :
752 : /*
753 : * No other process can put a worker in starting mode, so if
754 : * startingWorker is still INVALID after exchanging our lock,
755 : * we assume it's the same one we saw above (so we don't
756 : * recheck the launch time).
757 : */
758 0 : if (AutoVacuumShmem->av_startingWorker != NULL)
759 : {
760 0 : worker = AutoVacuumShmem->av_startingWorker;
761 0 : worker->wi_dboid = InvalidOid;
762 0 : worker->wi_tableoid = InvalidOid;
763 0 : worker->wi_sharedrel = false;
764 0 : worker->wi_proc = NULL;
765 0 : worker->wi_launchtime = 0;
766 0 : dlist_push_head(&AutoVacuumShmem->av_freeWorkers,
767 : &worker->wi_links);
768 0 : AutoVacuumShmem->av_startingWorker = NULL;
769 0 : elog(WARNING, "worker took too long to start; canceled");
770 : }
771 : }
772 : else
773 0 : can_launch = false;
774 : }
775 1254 : LWLockRelease(AutovacuumLock); /* either shared or exclusive */
776 :
777 : /* if we can't do anything, just go back to sleep */
778 1254 : if (!can_launch)
779 0 : continue;
780 :
781 : /* We're OK to start a new worker */
782 :
783 1254 : if (dlist_is_empty(&DatabaseList))
784 : {
785 : /*
786 : * Special case when the list is empty: start a worker right away.
787 : * This covers the initial case, when no database is in pgstats
788 : * (thus the list is empty). Note that the constraints in
789 : * launcher_determine_sleep keep us from starting workers too
790 : * quickly (at most once every autovacuum_naptime when the list is
791 : * empty).
792 : */
793 300 : launch_worker(current_time);
794 : }
795 : else
796 : {
797 : /*
798 : * because rebuild_database_list constructs a list with most
799 : * distant adl_next_worker first, we obtain our database from the
800 : * tail of the list.
801 : */
802 : avl_dbase *avdb;
803 :
804 954 : avdb = dlist_tail_element(avl_dbase, adl_node, &DatabaseList);
805 :
806 : /*
807 : * launch a worker if next_worker is right now or it is in the
808 : * past
809 : */
810 954 : if (TimestampDifferenceExceeds(avdb->adl_next_worker,
811 : current_time, 0))
812 22 : launch_worker(current_time);
813 : }
814 : }
815 :
816 : /* Normal exit from the autovac launcher is here */
817 : shutdown:
818 342 : ereport(DEBUG1,
819 : (errmsg("autovacuum launcher shutting down")));
820 342 : AutoVacuumShmem->av_launcherpid = 0;
821 :
822 342 : proc_exit(0); /* done */
823 : }
824 :
825 : /*
826 : * Determine the time to sleep, based on the database list.
827 : *
828 : * The "canlaunch" parameter indicates whether we can start a worker right now,
829 : * for example due to the workers being all busy. If this is false, we will
830 : * cause a long sleep, which will be interrupted when a worker exits.
831 : */
832 : static void
833 1600 : launcher_determine_sleep(bool canlaunch, bool recursing, struct timeval *nap)
834 : {
835 : /*
836 : * We sleep until the next scheduled vacuum. We trust that when the
837 : * database list was built, care was taken so that no entries have times
838 : * in the past; if the first entry has too close a next_worker value, or a
839 : * time in the past, we will sleep a small nominal time.
840 : */
841 1600 : if (!canlaunch)
842 : {
843 0 : nap->tv_sec = autovacuum_naptime;
844 0 : nap->tv_usec = 0;
845 : }
846 1600 : else if (!dlist_is_empty(&DatabaseList))
847 : {
848 1064 : TimestampTz current_time = GetCurrentTimestamp();
849 : TimestampTz next_wakeup;
850 : avl_dbase *avdb;
851 : long secs;
852 : int usecs;
853 :
854 1064 : avdb = dlist_tail_element(avl_dbase, adl_node, &DatabaseList);
855 :
856 1064 : next_wakeup = avdb->adl_next_worker;
857 1064 : TimestampDifference(current_time, next_wakeup, &secs, &usecs);
858 :
859 1064 : nap->tv_sec = secs;
860 1064 : nap->tv_usec = usecs;
861 : }
862 : else
863 : {
864 : /* list is empty, sleep for whole autovacuum_naptime seconds */
865 536 : nap->tv_sec = autovacuum_naptime;
866 536 : nap->tv_usec = 0;
867 : }
868 :
869 : /*
870 : * If the result is exactly zero, it means a database had an entry with
871 : * time in the past. Rebuild the list so that the databases are evenly
872 : * distributed again, and recalculate the time to sleep. This can happen
873 : * if there are more tables needing vacuum than workers, and they all take
874 : * longer to vacuum than autovacuum_naptime.
875 : *
876 : * We only recurse once. rebuild_database_list should always return times
877 : * in the future, but it seems best not to trust too much on that.
878 : */
879 1600 : if (nap->tv_sec == 0 && nap->tv_usec == 0 && !recursing)
880 : {
881 0 : rebuild_database_list(InvalidOid);
882 0 : launcher_determine_sleep(canlaunch, true, nap);
883 0 : return;
884 : }
885 :
886 : /* The smallest time we'll allow the launcher to sleep. */
887 1600 : if (nap->tv_sec <= 0 && nap->tv_usec <= MIN_AUTOVAC_SLEEPTIME * 1000)
888 : {
889 4 : nap->tv_sec = 0;
890 4 : nap->tv_usec = MIN_AUTOVAC_SLEEPTIME * 1000;
891 : }
892 :
893 : /*
894 : * If the sleep time is too large, clamp it to an arbitrary maximum (plus
895 : * any fractional seconds, for simplicity). This avoids an essentially
896 : * infinite sleep in strange cases like the system clock going backwards a
897 : * few years.
898 : */
899 1600 : if (nap->tv_sec > MAX_AUTOVAC_SLEEPTIME)
900 0 : nap->tv_sec = MAX_AUTOVAC_SLEEPTIME;
901 : }
902 :
903 : /*
904 : * Build an updated DatabaseList. It must only contain databases that appear
905 : * in pgstats, and must be sorted by next_worker from highest to lowest,
906 : * distributed regularly across the next autovacuum_naptime interval.
907 : *
908 : * Receives the Oid of the database that made this list be generated (we call
909 : * this the "new" database, because when the database was already present on
910 : * the list, we expect that this function is not called at all). The
911 : * preexisting list, if any, will be used to preserve the order of the
912 : * databases in the autovacuum_naptime period. The new database is put at the
913 : * end of the interval. The actual values are not saved, which should not be
914 : * much of a problem.
915 : */
916 : static void
917 386 : rebuild_database_list(Oid newdb)
918 : {
919 : List *dblist;
920 : ListCell *cell;
921 : MemoryContext newcxt;
922 : MemoryContext oldcxt;
923 : MemoryContext tmpcxt;
924 : HASHCTL hctl;
925 : int score;
926 : int nelems;
927 : HTAB *dbhash;
928 : dlist_iter iter;
929 :
930 : /* use fresh stats */
931 386 : autovac_refresh_stats();
932 :
933 386 : newcxt = AllocSetContextCreate(AutovacMemCxt,
934 : "AV dblist",
935 : ALLOCSET_DEFAULT_SIZES);
936 386 : tmpcxt = AllocSetContextCreate(newcxt,
937 : "tmp AV dblist",
938 : ALLOCSET_DEFAULT_SIZES);
939 386 : oldcxt = MemoryContextSwitchTo(tmpcxt);
940 :
941 : /*
942 : * Implementing this is not as simple as it sounds, because we need to put
943 : * the new database at the end of the list; next the databases that were
944 : * already on the list, and finally (at the tail of the list) all the
945 : * other databases that are not on the existing list.
946 : *
947 : * To do this, we build an empty hash table of scored databases. We will
948 : * start with the lowest score (zero) for the new database, then
949 : * increasing scores for the databases in the existing list, in order, and
950 : * lastly increasing scores for all databases gotten via
951 : * get_database_list() that are not already on the hash.
952 : *
953 : * Then we will put all the hash elements into an array, sort the array by
954 : * score, and finally put the array elements into the new doubly linked
955 : * list.
956 : */
957 386 : hctl.keysize = sizeof(Oid);
958 386 : hctl.entrysize = sizeof(avl_dbase);
959 386 : hctl.hcxt = tmpcxt;
960 386 : dbhash = hash_create("db hash", 20, &hctl, /* magic number here FIXME */
961 : HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
962 :
963 : /* start by inserting the new database */
964 386 : score = 0;
965 386 : if (OidIsValid(newdb))
966 : {
967 : avl_dbase *db;
968 : PgStat_StatDBEntry *entry;
969 :
970 : /* only consider this database if it has a pgstat entry */
971 32 : entry = pgstat_fetch_stat_dbentry(newdb);
972 32 : if (entry != NULL)
973 : {
974 : /* we assume it isn't found because the hash was just created */
975 32 : db = hash_search(dbhash, &newdb, HASH_ENTER, NULL);
976 :
977 : /* hash_search already filled in the key */
978 32 : db->adl_score = score++;
979 : /* next_worker is filled in later */
980 : }
981 : }
982 :
983 : /* Now insert the databases from the existing list */
984 390 : dlist_foreach(iter, &DatabaseList)
985 : {
986 4 : avl_dbase *avdb = dlist_container(avl_dbase, adl_node, iter.cur);
987 : avl_dbase *db;
988 : bool found;
989 : PgStat_StatDBEntry *entry;
990 :
991 : /*
992 : * skip databases with no stat entries -- in particular, this gets rid
993 : * of dropped databases
994 : */
995 4 : entry = pgstat_fetch_stat_dbentry(avdb->adl_datid);
996 4 : if (entry == NULL)
997 0 : continue;
998 :
999 4 : db = hash_search(dbhash, &(avdb->adl_datid), HASH_ENTER, &found);
1000 :
1001 4 : if (!found)
1002 : {
1003 : /* hash_search already filled in the key */
1004 4 : db->adl_score = score++;
1005 : /* next_worker is filled in later */
1006 : }
1007 : }
1008 :
1009 : /* finally, insert all qualifying databases not previously inserted */
1010 386 : dblist = get_database_list();
1011 1658 : foreach(cell, dblist)
1012 : {
1013 1272 : avw_dbase *avdb = lfirst(cell);
1014 : avl_dbase *db;
1015 : bool found;
1016 : PgStat_StatDBEntry *entry;
1017 :
1018 : /* only consider databases with a pgstat entry */
1019 1272 : entry = pgstat_fetch_stat_dbentry(avdb->adw_datid);
1020 1272 : if (entry == NULL)
1021 1090 : continue;
1022 :
1023 182 : db = hash_search(dbhash, &(avdb->adw_datid), HASH_ENTER, &found);
1024 : /* only update the score if the database was not already on the hash */
1025 182 : if (!found)
1026 : {
1027 : /* hash_search already filled in the key */
1028 146 : db->adl_score = score++;
1029 : /* next_worker is filled in later */
1030 : }
1031 : }
1032 386 : nelems = score;
1033 :
1034 : /* from here on, the allocated memory belongs to the new list */
1035 386 : MemoryContextSwitchTo(newcxt);
1036 386 : dlist_init(&DatabaseList);
1037 :
1038 386 : if (nelems > 0)
1039 : {
1040 : TimestampTz current_time;
1041 : int millis_increment;
1042 : avl_dbase *dbary;
1043 : avl_dbase *db;
1044 : HASH_SEQ_STATUS seq;
1045 : int i;
1046 :
1047 : /* put all the hash elements into an array */
1048 116 : dbary = palloc(nelems * sizeof(avl_dbase));
1049 :
1050 116 : i = 0;
1051 116 : hash_seq_init(&seq, dbhash);
1052 414 : while ((db = hash_seq_search(&seq)) != NULL)
1053 182 : memcpy(&(dbary[i++]), db, sizeof(avl_dbase));
1054 :
1055 : /* sort the array */
1056 116 : qsort(dbary, nelems, sizeof(avl_dbase), db_comparator);
1057 :
1058 : /*
1059 : * Determine the time interval between databases in the schedule. If
1060 : * we see that the configured naptime would take us to sleep times
1061 : * lower than our min sleep time (which launcher_determine_sleep is
1062 : * coded not to allow), silently use a larger naptime (but don't touch
1063 : * the GUC variable).
1064 : */
1065 116 : millis_increment = 1000.0 * autovacuum_naptime / nelems;
1066 116 : if (millis_increment <= MIN_AUTOVAC_SLEEPTIME)
1067 0 : millis_increment = MIN_AUTOVAC_SLEEPTIME * 1.1;
1068 :
1069 116 : current_time = GetCurrentTimestamp();
1070 :
1071 : /*
1072 : * move the elements from the array into the dllist, setting the
1073 : * next_worker while walking the array
1074 : */
1075 298 : for (i = 0; i < nelems; i++)
1076 : {
1077 182 : avl_dbase *db = &(dbary[i]);
1078 :
1079 182 : current_time = TimestampTzPlusMilliseconds(current_time,
1080 : millis_increment);
1081 182 : db->adl_next_worker = current_time;
1082 :
1083 : /* later elements should go closer to the head of the list */
1084 182 : dlist_push_head(&DatabaseList, &db->adl_node);
1085 : }
1086 : }
1087 :
1088 : /* all done, clean up memory */
1089 386 : if (DatabaseListCxt != NULL)
1090 40 : MemoryContextDelete(DatabaseListCxt);
1091 386 : MemoryContextDelete(tmpcxt);
1092 386 : DatabaseListCxt = newcxt;
1093 386 : MemoryContextSwitchTo(oldcxt);
1094 386 : }
1095 :
1096 : /* qsort comparator for avl_dbase, using adl_score */
1097 : static int
1098 92 : db_comparator(const void *a, const void *b)
1099 : {
1100 92 : if (((const avl_dbase *) a)->adl_score == ((const avl_dbase *) b)->adl_score)
1101 0 : return 0;
1102 : else
1103 92 : return (((const avl_dbase *) a)->adl_score < ((const avl_dbase *) b)->adl_score) ? 1 : -1;
1104 : }
1105 :
1106 : /*
1107 : * do_start_worker
1108 : *
1109 : * Bare-bones procedure for starting an autovacuum worker from the launcher.
1110 : * It determines what database to work on, sets up shared memory stuff and
1111 : * signals postmaster to start the worker. It fails gracefully if invoked when
1112 : * autovacuum_workers are already active.
1113 : *
1114 : * Return value is the OID of the database that the worker is going to process,
1115 : * or InvalidOid if no worker was actually started.
1116 : */
1117 : static Oid
1118 322 : do_start_worker(void)
1119 : {
1120 : List *dblist;
1121 : ListCell *cell;
1122 : TransactionId xidForceLimit;
1123 : MultiXactId multiForceLimit;
1124 : bool for_xid_wrap;
1125 : bool for_multi_wrap;
1126 : avw_dbase *avdb;
1127 : TimestampTz current_time;
1128 322 : bool skipit = false;
1129 322 : Oid retval = InvalidOid;
1130 : MemoryContext tmpcxt,
1131 : oldcxt;
1132 :
1133 : /* return quickly when there are no free workers */
1134 322 : LWLockAcquire(AutovacuumLock, LW_SHARED);
1135 322 : if (dlist_is_empty(&AutoVacuumShmem->av_freeWorkers))
1136 : {
1137 0 : LWLockRelease(AutovacuumLock);
1138 0 : return InvalidOid;
1139 : }
1140 322 : LWLockRelease(AutovacuumLock);
1141 :
1142 : /*
1143 : * Create and switch to a temporary context to avoid leaking the memory
1144 : * allocated for the database list.
1145 : */
1146 322 : tmpcxt = AllocSetContextCreate(CurrentMemoryContext,
1147 : "Start worker tmp cxt",
1148 : ALLOCSET_DEFAULT_SIZES);
1149 322 : oldcxt = MemoryContextSwitchTo(tmpcxt);
1150 :
1151 : /* use fresh stats */
1152 322 : autovac_refresh_stats();
1153 :
1154 : /* Get a list of databases */
1155 322 : dblist = get_database_list();
1156 :
1157 : /*
1158 : * Determine the oldest datfrozenxid/relfrozenxid that we will allow to
1159 : * pass without forcing a vacuum. (This limit can be tightened for
1160 : * particular tables, but not loosened.)
1161 : */
1162 322 : recentXid = ReadNewTransactionId();
1163 322 : xidForceLimit = recentXid - autovacuum_freeze_max_age;
1164 : /* ensure it's a "normal" XID, else TransactionIdPrecedes misbehaves */
1165 : /* this can cause the limit to go backwards by 3, but that's OK */
1166 322 : if (xidForceLimit < FirstNormalTransactionId)
1167 0 : xidForceLimit -= FirstNormalTransactionId;
1168 :
1169 : /* Also determine the oldest datminmxid we will consider. */
1170 322 : recentMulti = ReadNextMultiXactId();
1171 322 : multiForceLimit = recentMulti - MultiXactMemberFreezeThreshold();
1172 322 : if (multiForceLimit < FirstMultiXactId)
1173 0 : multiForceLimit -= FirstMultiXactId;
1174 :
1175 : /*
1176 : * Choose a database to connect to. We pick the database that was least
1177 : * recently auto-vacuumed, or one that needs vacuuming to prevent Xid
1178 : * wraparound-related data loss. If any db at risk of Xid wraparound is
1179 : * found, we pick the one with oldest datfrozenxid, independently of
1180 : * autovacuum times; similarly we pick the one with the oldest datminmxid
1181 : * if any is in MultiXactId wraparound. Note that those in Xid wraparound
1182 : * danger are given more priority than those in multi wraparound danger.
1183 : *
1184 : * Note that a database with no stats entry is not considered, except for
1185 : * Xid wraparound purposes. The theory is that if no one has ever
1186 : * connected to it since the stats were last initialized, it doesn't need
1187 : * vacuuming.
1188 : *
1189 : * XXX This could be improved if we had more info about whether it needs
1190 : * vacuuming before connecting to it. Perhaps look through the pgstats
1191 : * data for the database's tables? One idea is to keep track of the
1192 : * number of new and dead tuples per database in pgstats. However it
1193 : * isn't clear how to construct a metric that measures that and not cause
1194 : * starvation for less busy databases.
1195 : */
1196 322 : avdb = NULL;
1197 322 : for_xid_wrap = false;
1198 322 : for_multi_wrap = false;
1199 322 : current_time = GetCurrentTimestamp();
1200 1372 : foreach(cell, dblist)
1201 : {
1202 1050 : avw_dbase *tmp = lfirst(cell);
1203 : dlist_iter iter;
1204 :
1205 : /* Check to see if this one is at risk of wraparound */
1206 1050 : if (TransactionIdPrecedes(tmp->adw_frozenxid, xidForceLimit))
1207 : {
1208 0 : if (avdb == NULL ||
1209 0 : TransactionIdPrecedes(tmp->adw_frozenxid,
1210 : avdb->adw_frozenxid))
1211 0 : avdb = tmp;
1212 0 : for_xid_wrap = true;
1213 958 : continue;
1214 : }
1215 1050 : else if (for_xid_wrap)
1216 0 : continue; /* ignore not-at-risk DBs */
1217 1050 : else if (MultiXactIdPrecedes(tmp->adw_minmulti, multiForceLimit))
1218 : {
1219 0 : if (avdb == NULL ||
1220 0 : MultiXactIdPrecedes(tmp->adw_minmulti, avdb->adw_minmulti))
1221 0 : avdb = tmp;
1222 0 : for_multi_wrap = true;
1223 0 : continue;
1224 : }
1225 1050 : else if (for_multi_wrap)
1226 0 : continue; /* ignore not-at-risk DBs */
1227 :
1228 : /* Find pgstat entry if any */
1229 1050 : tmp->adw_entry = pgstat_fetch_stat_dbentry(tmp->adw_datid);
1230 :
1231 : /*
1232 : * Skip a database with no pgstat entry; it means it hasn't seen any
1233 : * activity.
1234 : */
1235 1050 : if (!tmp->adw_entry)
1236 926 : continue;
1237 :
1238 : /*
1239 : * Also, skip a database that appears on the database list as having
1240 : * been processed recently (less than autovacuum_naptime seconds ago).
1241 : * We do this so that we don't select a database which we just
1242 : * selected, but that pgstat hasn't gotten around to updating the last
1243 : * autovacuum time yet.
1244 : */
1245 124 : skipit = false;
1246 :
1247 202 : dlist_reverse_foreach(iter, &DatabaseList)
1248 : {
1249 132 : avl_dbase *dbp = dlist_container(avl_dbase, adl_node, iter.cur);
1250 :
1251 132 : if (dbp->adl_datid == tmp->adw_datid)
1252 : {
1253 : /*
1254 : * Skip this database if its next_worker value falls between
1255 : * the current time and the current time plus naptime.
1256 : */
1257 54 : if (!TimestampDifferenceExceeds(dbp->adl_next_worker,
1258 32 : current_time, 0) &&
1259 32 : !TimestampDifferenceExceeds(current_time,
1260 : dbp->adl_next_worker,
1261 : autovacuum_naptime * 1000))
1262 32 : skipit = true;
1263 :
1264 54 : break;
1265 : }
1266 : }
1267 124 : if (skipit)
1268 32 : continue;
1269 :
1270 : /*
1271 : * Remember the db with oldest autovac time. (If we are here, both
1272 : * tmp->entry and db->entry must be non-null.)
1273 : */
1274 132 : if (avdb == NULL ||
1275 40 : tmp->adw_entry->last_autovac_time < avdb->adw_entry->last_autovac_time)
1276 52 : avdb = tmp;
1277 : }
1278 :
1279 : /* Found a database -- process it */
1280 322 : if (avdb != NULL)
1281 : {
1282 : WorkerInfo worker;
1283 : dlist_node *wptr;
1284 :
1285 52 : LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
1286 :
1287 : /*
1288 : * Get a worker entry from the freelist. We checked above, so there
1289 : * really should be a free slot.
1290 : */
1291 52 : wptr = dlist_pop_head_node(&AutoVacuumShmem->av_freeWorkers);
1292 :
1293 52 : worker = dlist_container(WorkerInfoData, wi_links, wptr);
1294 52 : worker->wi_dboid = avdb->adw_datid;
1295 52 : worker->wi_proc = NULL;
1296 52 : worker->wi_launchtime = GetCurrentTimestamp();
1297 :
1298 52 : AutoVacuumShmem->av_startingWorker = worker;
1299 :
1300 52 : LWLockRelease(AutovacuumLock);
1301 :
1302 52 : SendPostmasterSignal(PMSIGNAL_START_AUTOVAC_WORKER);
1303 :
1304 52 : retval = avdb->adw_datid;
1305 : }
1306 270 : else if (skipit)
1307 : {
1308 : /*
1309 : * If we skipped all databases on the list, rebuild it, because it
1310 : * probably contains a dropped database.
1311 : */
1312 0 : rebuild_database_list(InvalidOid);
1313 : }
1314 :
1315 322 : MemoryContextSwitchTo(oldcxt);
1316 322 : MemoryContextDelete(tmpcxt);
1317 :
1318 322 : return retval;
1319 : }
1320 :
1321 : /*
1322 : * launch_worker
1323 : *
1324 : * Wrapper for starting a worker from the launcher. Besides actually starting
1325 : * it, update the database list to reflect the next time that another one will
1326 : * need to be started on the selected database. The actual database choice is
1327 : * left to do_start_worker.
1328 : *
1329 : * This routine is also expected to insert an entry into the database list if
1330 : * the selected database was previously absent from the list.
1331 : */
1332 : static void
1333 322 : launch_worker(TimestampTz now)
1334 : {
1335 : Oid dbid;
1336 : dlist_iter iter;
1337 :
1338 322 : dbid = do_start_worker();
1339 322 : if (OidIsValid(dbid))
1340 : {
1341 52 : bool found = false;
1342 :
1343 : /*
1344 : * Walk the database list and update the corresponding entry. If the
1345 : * database is not on the list, we'll recreate the list.
1346 : */
1347 86 : dlist_foreach(iter, &DatabaseList)
1348 : {
1349 54 : avl_dbase *avdb = dlist_container(avl_dbase, adl_node, iter.cur);
1350 :
1351 54 : if (avdb->adl_datid == dbid)
1352 : {
1353 20 : found = true;
1354 :
1355 : /*
1356 : * add autovacuum_naptime seconds to the current time, and use
1357 : * that as the new "next_worker" field for this database.
1358 : */
1359 20 : avdb->adl_next_worker =
1360 20 : TimestampTzPlusMilliseconds(now, autovacuum_naptime * 1000);
1361 :
1362 20 : dlist_move_head(&DatabaseList, iter.cur);
1363 20 : break;
1364 : }
1365 : }
1366 :
1367 : /*
1368 : * If the database was not present in the database list, we rebuild
1369 : * the list. It's possible that the database does not get into the
1370 : * list anyway, for example if it's a database that doesn't have a
1371 : * pgstat entry, but this is not a problem because we don't want to
1372 : * schedule workers regularly into those in any case.
1373 : */
1374 52 : if (!found)
1375 32 : rebuild_database_list(dbid);
1376 : }
1377 322 : }
1378 :
1379 : /*
1380 : * Called from postmaster to signal a failure to fork a process to become
1381 : * worker. The postmaster should kill(SIGUSR2) the launcher shortly
1382 : * after calling this function.
1383 : */
1384 : void
1385 0 : AutoVacWorkerFailed(void)
1386 : {
1387 0 : AutoVacuumShmem->av_signal[AutoVacForkFailed] = true;
1388 0 : }
1389 :
1390 : /* SIGHUP: set flag to re-read config file at next convenient time */
1391 : static void
1392 8 : av_sighup_handler(SIGNAL_ARGS)
1393 : {
1394 8 : int save_errno = errno;
1395 :
1396 8 : got_SIGHUP = true;
1397 8 : SetLatch(MyLatch);
1398 :
1399 8 : errno = save_errno;
1400 8 : }
1401 :
1402 : /* SIGUSR2: a worker is up and running, or just finished, or failed to fork */
1403 : static void
1404 104 : avl_sigusr2_handler(SIGNAL_ARGS)
1405 : {
1406 104 : int save_errno = errno;
1407 :
1408 104 : got_SIGUSR2 = true;
1409 104 : SetLatch(MyLatch);
1410 :
1411 104 : errno = save_errno;
1412 104 : }
1413 :
1414 : /* SIGTERM: time to die */
1415 : static void
1416 346 : avl_sigterm_handler(SIGNAL_ARGS)
1417 : {
1418 346 : int save_errno = errno;
1419 :
1420 346 : got_SIGTERM = true;
1421 346 : SetLatch(MyLatch);
1422 :
1423 346 : errno = save_errno;
1424 346 : }
1425 :
1426 :
1427 : /********************************************************************
1428 : * AUTOVACUUM WORKER CODE
1429 : ********************************************************************/
1430 :
1431 : #ifdef EXEC_BACKEND
1432 : /*
1433 : * forkexec routines for the autovacuum worker.
1434 : *
1435 : * Format up the arglist, then fork and exec.
1436 : */
1437 : static pid_t
1438 : avworker_forkexec(void)
1439 : {
1440 : char *av[10];
1441 : int ac = 0;
1442 :
1443 : av[ac++] = "postgres";
1444 : av[ac++] = "--forkavworker";
1445 : av[ac++] = NULL; /* filled in by postmaster_forkexec */
1446 : av[ac] = NULL;
1447 :
1448 : Assert(ac < lengthof(av));
1449 :
1450 : return postmaster_forkexec(ac, av);
1451 : }
1452 :
1453 : /*
1454 : * We need this set from the outside, before InitProcess is called
1455 : */
1456 : void
1457 : AutovacuumWorkerIAm(void)
1458 : {
1459 : am_autovacuum_worker = true;
1460 : }
1461 : #endif
1462 :
1463 : /*
1464 : * Main entry point for autovacuum worker process.
1465 : *
1466 : * This code is heavily based on pgarch.c, q.v.
1467 : */
1468 : int
1469 62 : StartAutoVacWorker(void)
1470 : {
1471 : pid_t worker_pid;
1472 :
1473 : #ifdef EXEC_BACKEND
1474 : switch ((worker_pid = avworker_forkexec()))
1475 : #else
1476 62 : switch ((worker_pid = fork_process()))
1477 : #endif
1478 : {
1479 : case -1:
1480 0 : ereport(LOG,
1481 : (errmsg("could not fork autovacuum worker process: %m")));
1482 0 : return 0;
1483 :
1484 : #ifndef EXEC_BACKEND
1485 : case 0:
1486 : /* in postmaster child ... */
1487 62 : InitPostmasterChild();
1488 :
1489 : /* Close the postmaster's sockets */
1490 62 : ClosePostmasterPorts(false);
1491 :
1492 62 : AutoVacWorkerMain(0, NULL);
1493 : break;
1494 : #endif
1495 : default:
1496 62 : return (int) worker_pid;
1497 : }
1498 :
1499 : /* shouldn't get here */
1500 : return 0;
1501 : }
1502 :
1503 : /*
1504 : * AutoVacWorkerMain
1505 : */
1506 : NON_EXEC_STATIC void
1507 62 : AutoVacWorkerMain(int argc, char *argv[])
1508 : {
1509 : sigjmp_buf local_sigjmp_buf;
1510 : Oid dbid;
1511 :
1512 62 : am_autovacuum_worker = true;
1513 :
1514 : /* Identify myself via ps */
1515 62 : init_ps_display(pgstat_get_backend_desc(B_AUTOVAC_WORKER), "", "", "");
1516 :
1517 62 : SetProcessingMode(InitProcessing);
1518 :
1519 : /*
1520 : * Set up signal handlers. We operate on databases much like a regular
1521 : * backend, so we use the same signal handling. See equivalent code in
1522 : * tcop/postgres.c.
1523 : */
1524 62 : pqsignal(SIGHUP, av_sighup_handler);
1525 :
1526 : /*
1527 : * SIGINT is used to signal canceling the current table's vacuum; SIGTERM
1528 : * means abort and exit cleanly, and SIGQUIT means abandon ship.
1529 : */
1530 62 : pqsignal(SIGINT, StatementCancelHandler);
1531 62 : pqsignal(SIGTERM, die);
1532 62 : pqsignal(SIGQUIT, quickdie);
1533 62 : InitializeTimeouts(); /* establishes SIGALRM handler */
1534 :
1535 62 : pqsignal(SIGPIPE, SIG_IGN);
1536 62 : pqsignal(SIGUSR1, procsignal_sigusr1_handler);
1537 62 : pqsignal(SIGUSR2, SIG_IGN);
1538 62 : pqsignal(SIGFPE, FloatExceptionHandler);
1539 62 : pqsignal(SIGCHLD, SIG_DFL);
1540 :
1541 : /* Early initialization */
1542 62 : BaseInit();
1543 :
1544 : /*
1545 : * Create a per-backend PGPROC struct in shared memory, except in the
1546 : * EXEC_BACKEND case where this was done in SubPostmasterMain. We must do
1547 : * this before we can use LWLocks (and in the EXEC_BACKEND case we already
1548 : * had to do some stuff with LWLocks).
1549 : */
1550 : #ifndef EXEC_BACKEND
1551 62 : InitProcess();
1552 : #endif
1553 :
1554 : /*
1555 : * If an exception is encountered, processing resumes here.
1556 : *
1557 : * See notes in postgres.c about the design of this coding.
1558 : */
1559 62 : if (sigsetjmp(local_sigjmp_buf, 1) != 0)
1560 : {
1561 : /* Prevents interrupts while cleaning up */
1562 0 : HOLD_INTERRUPTS();
1563 :
1564 : /* Report the error to the server log */
1565 0 : 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 0 : proc_exit(0);
1573 : }
1574 :
1575 : /* We can now handle ereport(ERROR) */
1576 62 : PG_exception_stack = &local_sigjmp_buf;
1577 :
1578 62 : PG_SETMASK(&UnBlockSig);
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 62 : 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 62 : 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 62 : SetConfigOption("statement_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
1600 62 : SetConfigOption("lock_timeout", "0", PGC_SUSET, PGC_S_OVERRIDE);
1601 62 : SetConfigOption("idle_in_transaction_session_timeout", "0",
1602 : PGC_SUSET, PGC_S_OVERRIDE);
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 62 : SetConfigOption("default_transaction_isolation", "read committed",
1610 : PGC_SUSET, PGC_S_OVERRIDE);
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 : */
1617 62 : if (synchronous_commit > SYNCHRONOUS_COMMIT_LOCAL_FLUSH)
1618 62 : SetConfigOption("synchronous_commit", "local",
1619 : PGC_SUSET, PGC_S_OVERRIDE);
1620 :
1621 : /*
1622 : * Get the info about the database we're going to work on.
1623 : */
1624 62 : 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 62 : if (AutoVacuumShmem->av_startingWorker != NULL)
1633 : {
1634 62 : MyWorkerInfo = AutoVacuumShmem->av_startingWorker;
1635 62 : dbid = MyWorkerInfo->wi_dboid;
1636 62 : MyWorkerInfo->wi_proc = MyProc;
1637 :
1638 : /* insert into the running list */
1639 62 : dlist_push_head(&AutoVacuumShmem->av_runningWorkers,
1640 62 : &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 62 : AutoVacuumShmem->av_startingWorker = NULL;
1647 62 : LWLockRelease(AutovacuumLock);
1648 :
1649 62 : on_shmem_exit(FreeWorkerInfo, 0);
1650 :
1651 : /* wake up the launcher */
1652 62 : if (AutoVacuumShmem->av_launcherpid != 0)
1653 62 : kill(AutoVacuumShmem->av_launcherpid, SIGUSR2);
1654 : }
1655 : else
1656 : {
1657 : /* no worker entry for me, go away */
1658 0 : elog(WARNING, "autovacuum worker started without a worker entry");
1659 0 : dbid = InvalidOid;
1660 0 : LWLockRelease(AutovacuumLock);
1661 : }
1662 :
1663 62 : 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 62 : 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 62 : InitPostgres(NULL, dbid, NULL, InvalidOid, dbname, false);
1684 60 : SetProcessingMode(NormalProcessing);
1685 60 : set_ps_display(dbname, false);
1686 60 : ereport(DEBUG1,
1687 : (errmsg("autovacuum: processing database \"%s\"", dbname)));
1688 :
1689 60 : if (PostAuthDelay)
1690 0 : pg_usleep(PostAuthDelay * 1000000L);
1691 :
1692 : /* And do an appropriate amount of work */
1693 60 : recentXid = ReadNewTransactionId();
1694 60 : recentMulti = ReadNextMultiXactId();
1695 60 : 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 60 : proc_exit(0);
1705 : }
1706 :
1707 : /*
1708 : * Return a WorkerInfo to the free list
1709 : */
1710 : static void
1711 62 : FreeWorkerInfo(int code, Datum arg)
1712 : {
1713 62 : if (MyWorkerInfo != NULL)
1714 : {
1715 62 : 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 62 : AutovacuumLauncherPid = AutoVacuumShmem->av_launcherpid;
1730 :
1731 62 : dlist_delete(&MyWorkerInfo->wi_links);
1732 62 : MyWorkerInfo->wi_dboid = InvalidOid;
1733 62 : MyWorkerInfo->wi_tableoid = InvalidOid;
1734 62 : MyWorkerInfo->wi_sharedrel = false;
1735 62 : MyWorkerInfo->wi_proc = NULL;
1736 62 : MyWorkerInfo->wi_launchtime = 0;
1737 62 : MyWorkerInfo->wi_dobalance = false;
1738 62 : MyWorkerInfo->wi_cost_delay = 0;
1739 62 : MyWorkerInfo->wi_cost_limit = 0;
1740 62 : MyWorkerInfo->wi_cost_limit_base = 0;
1741 62 : dlist_push_head(&AutoVacuumShmem->av_freeWorkers,
1742 62 : &MyWorkerInfo->wi_links);
1743 : /* not mine anymore */
1744 62 : MyWorkerInfo = NULL;
1745 :
1746 : /*
1747 : * now that we're inactive, cause a rebalancing of the surviving
1748 : * workers
1749 : */
1750 62 : AutoVacuumShmem->av_signal[AutoVacRebalance] = true;
1751 62 : LWLockRelease(AutovacuumLock);
1752 : }
1753 62 : }
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
1760 1178 : AutoVacuumUpdateDelay(void)
1761 : {
1762 1178 : if (MyWorkerInfo)
1763 : {
1764 1178 : VacuumCostDelay = MyWorkerInfo->wi_cost_delay;
1765 1178 : VacuumCostLimit = MyWorkerInfo->wi_cost_limit;
1766 : }
1767 1178 : }
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
1776 398 : autovac_balance_cost(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 796 : int vac_cost_limit = (autovacuum_vac_cost_limit > 0 ?
1787 398 : autovacuum_vac_cost_limit : VacuumCostLimit);
1788 796 : double vac_cost_delay = (autovacuum_vac_cost_delay >= 0 ?
1789 398 : autovacuum_vac_cost_delay : VacuumCostDelay);
1790 : double cost_total;
1791 : double cost_avail;
1792 : dlist_iter iter;
1793 :
1794 : /* not set? nothing to do */
1795 398 : if (vac_cost_limit <= 0 || vac_cost_delay <= 0)
1796 58 : return;
1797 :
1798 : /* calculate the total base cost limit of participating active workers */
1799 398 : cost_total = 0.0;
1800 738 : dlist_foreach(iter, &AutoVacuumShmem->av_runningWorkers)
1801 : {
1802 340 : WorkerInfo worker = dlist_container(WorkerInfoData, wi_links, iter.cur);
1803 :
1804 680 : if (worker->wi_proc != NULL &&
1805 680 : worker->wi_dobalance &&
1806 680 : worker->wi_cost_limit_base > 0 && worker->wi_cost_delay > 0)
1807 340 : cost_total +=
1808 340 : (double) worker->wi_cost_limit_base / worker->wi_cost_delay;
1809 : }
1810 :
1811 : /* there are no cost limits -- nothing to do */
1812 398 : if (cost_total <= 0)
1813 58 : 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 340 : cost_avail = (double) vac_cost_limit / vac_cost_delay;
1820 680 : dlist_foreach(iter, &AutoVacuumShmem->av_runningWorkers)
1821 : {
1822 340 : WorkerInfo worker = dlist_container(WorkerInfoData, wi_links, iter.cur);
1823 :
1824 680 : if (worker->wi_proc != NULL &&
1825 680 : worker->wi_dobalance &&
1826 680 : worker->wi_cost_limit_base > 0 && worker->wi_cost_delay > 0)
1827 : {
1828 340 : int limit = (int)
1829 340 : (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 340 : worker->wi_cost_limit = Max(Min(limit,
1838 : worker->wi_cost_limit_base),
1839 : 1);
1840 : }
1841 :
1842 340 : if (worker->wi_proc != NULL)
1843 340 : 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 *
1864 708 : get_database_list(void)
1865 : {
1866 708 : 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 708 : 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 : */
1882 708 : StartTransactionCommand();
1883 708 : (void) GetTransactionSnapshot();
1884 :
1885 708 : rel = table_open(DatabaseRelationId, AccessShareLock);
1886 708 : scan = table_beginscan_catalog(rel, 0, NULL);
1887 :
1888 3738 : while (HeapTupleIsValid(tup = heap_getnext(scan, ForwardScanDirection)))
1889 : {
1890 2322 : 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 2322 : oldcxt = MemoryContextSwitchTo(resultcxt);
1901 :
1902 2322 : avdb = (avw_dbase *) palloc(sizeof(avw_dbase));
1903 :
1904 2322 : avdb->adw_datid = pgdatabase->oid;
1905 2322 : avdb->adw_name = pstrdup(NameStr(pgdatabase->datname));
1906 2322 : avdb->adw_frozenxid = pgdatabase->datfrozenxid;
1907 2322 : avdb->adw_minmulti = pgdatabase->datminmxid;
1908 : /* this gets set later: */
1909 2322 : avdb->adw_entry = NULL;
1910 :
1911 2322 : dblist = lappend(dblist, avdb);
1912 2322 : MemoryContextSwitchTo(oldcxt);
1913 : }
1914 :
1915 708 : table_endscan(scan);
1916 708 : table_close(rel, AccessShareLock);
1917 :
1918 708 : CommitTransactionCommand();
1919 :
1920 708 : 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
1930 60 : do_autovacuum(void)
1931 : {
1932 : Relation classRel;
1933 : HeapTuple tuple;
1934 : TableScanDesc relScan;
1935 : Form_pg_database dbForm;
1936 60 : List *table_oids = NIL;
1937 60 : 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 60 : bool did_vacuum = false;
1948 60 : 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 60 : AutovacMemCxt = AllocSetContextCreate(TopMemoryContext,
1957 : "AV worker",
1958 : ALLOCSET_DEFAULT_SIZES);
1959 60 : 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 : */
1965 60 : dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
1966 :
1967 : /* Start a transaction so our commands have one to play into. */
1968 60 : StartTransactionCommand();
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 : */
1975 60 : pgstat_vacuum_stat();
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 60 : 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 : */
1989 60 : tuple = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(MyDatabaseId));
1990 60 : if (!HeapTupleIsValid(tuple))
1991 0 : elog(ERROR, "cache lookup failed for database %u", MyDatabaseId);
1992 60 : dbForm = (Form_pg_database) GETSTRUCT(tuple);
1993 :
1994 60 : if (dbForm->datistemplate || !dbForm->datallowconn)
1995 : {
1996 0 : default_freeze_min_age = 0;
1997 0 : default_freeze_table_age = 0;
1998 0 : default_multixact_freeze_min_age = 0;
1999 0 : default_multixact_freeze_table_age = 0;
2000 : }
2001 : else
2002 : {
2003 60 : default_freeze_min_age = vacuum_freeze_min_age;
2004 60 : default_freeze_table_age = vacuum_freeze_table_age;
2005 60 : default_multixact_freeze_min_age = vacuum_multixact_freeze_min_age;
2006 60 : default_multixact_freeze_table_age = vacuum_multixact_freeze_table_age;
2007 : }
2008 :
2009 60 : ReleaseSysCache(tuple);
2010 :
2011 : /* StartTransactionCommand changed elsewhere */
2012 60 : MemoryContextSwitchTo(AutovacMemCxt);
2013 :
2014 : /* The database hash where pgstat keeps shared relations */
2015 60 : shared = pgstat_fetch_stat_dbentry(InvalidOid);
2016 :
2017 60 : classRel = table_open(RelationRelationId, AccessShareLock);
2018 :
2019 : /* create a copy so we can use it after closing pg_class */
2020 60 : pg_class_desc = CreateTupleDescCopy(RelationGetDescr(classRel));
2021 :
2022 : /* create hash table for toast <-> main relid mapping */
2023 60 : MemSet(&ctl, 0, sizeof(ctl));
2024 60 : ctl.keysize = sizeof(Oid);
2025 60 : ctl.entrysize = sizeof(av_relation);
2026 :
2027 60 : 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 60 : 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 27678 : while ((tuple = heap_getnext(relScan, ForwardScanDirection)) != NULL)
2053 : {
2054 27558 : 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 49468 : if (classForm->relkind != RELKIND_RELATION &&
2063 21910 : classForm->relkind != RELKIND_MATVIEW)
2064 43748 : continue;
2065 :
2066 5690 : 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 5690 : 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.
2077 : */
2078 12 : if (!isTempNamespaceInUse(classForm->relnamespace))
2079 : {
2080 : /*
2081 : * The table seems to be orphaned -- although it might be that
2082 : * the owning backend has already deleted it and exited; our
2083 : * pg_class scan snapshot is not necessarily up-to-date
2084 : * anymore, so we could be looking at a committed-dead entry.
2085 : * Remember it so we can try to delete it later.
2086 : */
2087 0 : orphan_oids = lappend_oid(orphan_oids, relid);
2088 : }
2089 12 : continue;
2090 : }
2091 :
2092 : /* Fetch reloptions and the pgstat entry for this table */
2093 5678 : relopts = extract_autovac_opts(tuple, pg_class_desc);
2094 5678 : tabentry = get_pgstat_tabentry_relid(relid, classForm->relisshared,
2095 : shared, dbentry);
2096 :
2097 : /* Check if it needs vacuum or analyze */
2098 5678 : relation_needs_vacanalyze(relid, relopts, classForm, tabentry,
2099 : effective_multixact_freeze_max_age,
2100 : &dovacuum, &doanalyze, &wraparound);
2101 :
2102 : /* Relations that need work are added to table_oids */
2103 5678 : if (dovacuum || doanalyze)
2104 340 : table_oids = lappend_oid(table_oids, relid);
2105 :
2106 : /*
2107 : * Remember TOAST associations for the second pass. Note: we must do
2108 : * this whether or not the table is going to be vacuumed, because we
2109 : * don't automatically vacuum toast tables along the parent table.
2110 : */
2111 5678 : if (OidIsValid(classForm->reltoastrelid))
2112 : {
2113 : av_relation *hentry;
2114 : bool found;
2115 :
2116 3144 : hentry = hash_search(table_toast_map,
2117 3144 : &classForm->reltoastrelid,
2118 : HASH_ENTER, &found);
2119 :
2120 3144 : if (!found)
2121 : {
2122 : /* hash_search already filled in the key */
2123 3144 : hentry->ar_relid = relid;
2124 3144 : hentry->ar_hasrelopts = false;
2125 3144 : if (relopts != NULL)
2126 : {
2127 18 : hentry->ar_hasrelopts = true;
2128 18 : memcpy(&hentry->ar_reloptions, relopts,
2129 : sizeof(AutoVacOpts));
2130 : }
2131 : }
2132 : }
2133 : }
2134 :
2135 60 : table_endscan(relScan);
2136 :
2137 : /* second pass: check TOAST tables */
2138 60 : ScanKeyInit(&key,
2139 : Anum_pg_class_relkind,
2140 : BTEqualStrategyNumber, F_CHAREQ,
2141 : CharGetDatum(RELKIND_TOASTVALUE));
2142 :
2143 60 : relScan = table_beginscan_catalog(classRel, 1, &key);
2144 3268 : while ((tuple = heap_getnext(relScan, ForwardScanDirection)) != NULL)
2145 : {
2146 3148 : Form_pg_class classForm = (Form_pg_class) GETSTRUCT(tuple);
2147 : PgStat_StatTabEntry *tabentry;
2148 : Oid relid;
2149 3148 : AutoVacOpts *relopts = NULL;
2150 : bool dovacuum;
2151 : bool doanalyze;
2152 : bool wraparound;
2153 :
2154 : /*
2155 : * We cannot safely process other backends' temp tables, so skip 'em.
2156 : */
2157 3148 : if (classForm->relpersistence == RELPERSISTENCE_TEMP)
2158 4 : continue;
2159 :
2160 3144 : relid = classForm->oid;
2161 :
2162 : /*
2163 : * fetch reloptions -- if this toast table does not have them, try the
2164 : * main rel
2165 : */
2166 3144 : relopts = extract_autovac_opts(tuple, pg_class_desc);
2167 3144 : if (relopts == NULL)
2168 : {
2169 : av_relation *hentry;
2170 : bool found;
2171 :
2172 3144 : hentry = hash_search(table_toast_map, &relid, HASH_FIND, &found);
2173 3144 : if (found && hentry->ar_hasrelopts)
2174 18 : relopts = &hentry->ar_reloptions;
2175 : }
2176 :
2177 : /* Fetch the pgstat entry for this table */
2178 3144 : tabentry = get_pgstat_tabentry_relid(relid, classForm->relisshared,
2179 : shared, dbentry);
2180 :
2181 3144 : relation_needs_vacanalyze(relid, relopts, classForm, tabentry,
2182 : effective_multixact_freeze_max_age,
2183 : &dovacuum, &doanalyze, &wraparound);
2184 :
2185 : /* ignore analyze for toast tables */
2186 3144 : if (dovacuum)
2187 0 : table_oids = lappend_oid(table_oids, relid);
2188 : }
2189 :
2190 60 : table_endscan(relScan);
2191 60 : table_close(classRel, AccessShareLock);
2192 :
2193 : /*
2194 : * Recheck orphan temporary tables, and if they still seem orphaned, drop
2195 : * them. We'll eat a transaction per dropped table, which might seem
2196 : * excessive, but we should only need to do anything as a result of a
2197 : * previous backend crash, so this should not happen often enough to
2198 : * justify "optimizing". Using separate transactions ensures that we
2199 : * don't bloat the lock table if there are many temp tables to be dropped,
2200 : * and it ensures that we don't lose work if a deletion attempt fails.
2201 : */
2202 60 : foreach(cell, orphan_oids)
2203 : {
2204 0 : Oid relid = lfirst_oid(cell);
2205 : Form_pg_class classForm;
2206 : ObjectAddress object;
2207 :
2208 : /*
2209 : * Check for user-requested abort.
2210 : */
2211 0 : CHECK_FOR_INTERRUPTS();
2212 :
2213 : /*
2214 : * Try to lock the table. If we can't get the lock immediately,
2215 : * somebody else is using (or dropping) the table, so it's not our
2216 : * concern anymore. Having the lock prevents race conditions below.
2217 : */
2218 0 : if (!ConditionalLockRelationOid(relid, AccessExclusiveLock))
2219 0 : continue;
2220 :
2221 : /*
2222 : * Re-fetch the pg_class tuple and re-check whether it still seems to
2223 : * be an orphaned temp table. If it's not there or no longer the same
2224 : * relation, ignore it.
2225 : */
2226 0 : tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
2227 0 : if (!HeapTupleIsValid(tuple))
2228 : {
2229 : /* be sure to drop useless lock so we don't bloat lock table */
2230 0 : UnlockRelationOid(relid, AccessExclusiveLock);
2231 0 : continue;
2232 : }
2233 0 : classForm = (Form_pg_class) GETSTRUCT(tuple);
2234 :
2235 : /*
2236 : * Make all the same tests made in the loop above. In event of OID
2237 : * counter wraparound, the pg_class entry we have now might be
2238 : * completely unrelated to the one we saw before.
2239 : */
2240 0 : if (!((classForm->relkind == RELKIND_RELATION ||
2241 0 : classForm->relkind == RELKIND_MATVIEW) &&
2242 0 : classForm->relpersistence == RELPERSISTENCE_TEMP))
2243 : {
2244 0 : UnlockRelationOid(relid, AccessExclusiveLock);
2245 0 : continue;
2246 : }
2247 :
2248 0 : if (isTempNamespaceInUse(classForm->relnamespace))
2249 : {
2250 0 : UnlockRelationOid(relid, AccessExclusiveLock);
2251 0 : continue;
2252 : }
2253 :
2254 : /* OK, let's delete it */
2255 0 : ereport(LOG,
2256 : (errmsg("autovacuum: dropping orphan temp table \"%s.%s.%s\"",
2257 : get_database_name(MyDatabaseId),
2258 : get_namespace_name(classForm->relnamespace),
2259 : NameStr(classForm->relname))));
2260 :
2261 0 : object.classId = RelationRelationId;
2262 0 : object.objectId = relid;
2263 0 : object.objectSubId = 0;
2264 0 : performDeletion(&object, DROP_CASCADE,
2265 : PERFORM_DELETION_INTERNAL |
2266 : PERFORM_DELETION_QUIETLY |
2267 : PERFORM_DELETION_SKIP_EXTENSIONS);
2268 :
2269 : /*
2270 : * To commit the deletion, end current transaction and start a new
2271 : * one. Note this also releases the lock we took.
2272 : */
2273 0 : CommitTransactionCommand();
2274 0 : StartTransactionCommand();
2275 :
2276 : /* StartTransactionCommand changed current memory context */
2277 0 : MemoryContextSwitchTo(AutovacMemCxt);
2278 : }
2279 :
2280 : /*
2281 : * Create a buffer access strategy object for VACUUM to use. We want to
2282 : * use the same one across all the vacuum operations we perform, since the
2283 : * point is for VACUUM not to blow out the shared cache.
2284 : */
2285 60 : bstrategy = GetAccessStrategy(BAS_VACUUM);
2286 :
2287 : /*
2288 : * create a memory context to act as fake PortalContext, so that the
2289 : * contexts created in the vacuum code are cleaned up for each table.
2290 : */
2291 60 : PortalContext = AllocSetContextCreate(AutovacMemCxt,
2292 : "Autovacuum Portal",
2293 : ALLOCSET_DEFAULT_SIZES);
2294 :
2295 : /*
2296 : * Perform operations on collected tables.
2297 : */
2298 400 : foreach(cell, table_oids)
2299 : {
2300 340 : Oid relid = lfirst_oid(cell);
2301 : HeapTuple classTup;
2302 : autovac_table *tab;
2303 : bool isshared;
2304 : bool skipit;
2305 : double stdVacuumCostDelay;
2306 : int stdVacuumCostLimit;
2307 : dlist_iter iter;
2308 :
2309 340 : CHECK_FOR_INTERRUPTS();
2310 :
2311 : /*
2312 : * Check for config changes before processing each collected table.
2313 : */
2314 340 : if (got_SIGHUP)
2315 : {
2316 0 : got_SIGHUP = false;
2317 0 : ProcessConfigFile(PGC_SIGHUP);
2318 :
2319 : /*
2320 : * You might be tempted to bail out if we see autovacuum is now
2321 : * disabled. Must resist that temptation -- this might be a
2322 : * for-wraparound emergency worker, in which case that would be
2323 : * entirely inappropriate.
2324 : */
2325 : }
2326 :
2327 : /*
2328 : * Find out whether the table is shared or not. (It's slightly
2329 : * annoying to fetch the syscache entry just for this, but in typical
2330 : * cases it adds little cost because table_recheck_autovac would
2331 : * refetch the entry anyway. We could buy that back by copying the
2332 : * tuple here and passing it to table_recheck_autovac, but that
2333 : * increases the odds of that function working with stale data.)
2334 : */
2335 340 : classTup = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
2336 340 : if (!HeapTupleIsValid(classTup))
2337 0 : continue; /* somebody deleted the rel, forget it */
2338 340 : isshared = ((Form_pg_class) GETSTRUCT(classTup))->relisshared;
2339 340 : ReleaseSysCache(classTup);
2340 :
2341 : /*
2342 : * Hold schedule lock from here until we've claimed the table. We
2343 : * also need the AutovacuumLock to walk the worker array, but that one
2344 : * can just be a shared lock.
2345 : */
2346 340 : LWLockAcquire(AutovacuumScheduleLock, LW_EXCLUSIVE);
2347 340 : LWLockAcquire(AutovacuumLock, LW_SHARED);
2348 :
2349 : /*
2350 : * Check whether the table is being vacuumed concurrently by another
2351 : * worker.
2352 : */
2353 340 : skipit = false;
2354 680 : dlist_foreach(iter, &AutoVacuumShmem->av_runningWorkers)
2355 : {
2356 340 : WorkerInfo worker = dlist_container(WorkerInfoData, wi_links, iter.cur);
2357 :
2358 : /* ignore myself */
2359 340 : if (worker == MyWorkerInfo)
2360 340 : continue;
2361 :
2362 : /* ignore workers in other databases (unless table is shared) */
2363 0 : if (!worker->wi_sharedrel && worker->wi_dboid != MyDatabaseId)
2364 0 : continue;
2365 :
2366 0 : if (worker->wi_tableoid == relid)
2367 : {
2368 0 : skipit = true;
2369 0 : found_concurrent_worker = true;
2370 0 : break;
2371 : }
2372 : }
2373 340 : LWLockRelease(AutovacuumLock);
2374 340 : if (skipit)
2375 : {
2376 0 : LWLockRelease(AutovacuumScheduleLock);
2377 0 : continue;
2378 : }
2379 :
2380 : /*
2381 : * Store the table's OID in shared memory before releasing the
2382 : * schedule lock, so that other workers don't try to vacuum it
2383 : * concurrently. (We claim it here so as not to hold
2384 : * AutovacuumScheduleLock while rechecking the stats.)
2385 : */
2386 340 : MyWorkerInfo->wi_tableoid = relid;
2387 340 : MyWorkerInfo->wi_sharedrel = isshared;
2388 340 : LWLockRelease(AutovacuumScheduleLock);
2389 :
2390 : /*
2391 : * Check whether pgstat data still says we need to vacuum this table.
2392 : * It could have changed if something else processed the table while
2393 : * we weren't looking.
2394 : *
2395 : * Note: we have a special case in pgstat code to ensure that the
2396 : * stats we read are as up-to-date as possible, to avoid the problem
2397 : * that somebody just finished vacuuming this table. The window to
2398 : * the race condition is not closed but it is very small.
2399 : */
2400 340 : MemoryContextSwitchTo(AutovacMemCxt);
2401 340 : tab = table_recheck_autovac(relid, table_toast_map, pg_class_desc,
2402 : effective_multixact_freeze_max_age);
2403 340 : if (tab == NULL)
2404 : {
2405 : /* someone else vacuumed the table, or it went away */
2406 0 : LWLockAcquire(AutovacuumScheduleLock, LW_EXCLUSIVE);
2407 0 : MyWorkerInfo->wi_tableoid = InvalidOid;
2408 0 : MyWorkerInfo->wi_sharedrel = false;
2409 0 : LWLockRelease(AutovacuumScheduleLock);
2410 0 : continue;
2411 : }
2412 :
2413 : /*
2414 : * Remember the prevailing values of the vacuum cost GUCs. We have to
2415 : * restore these at the bottom of the loop, else we'll compute wrong
2416 : * values in the next iteration of autovac_balance_cost().
2417 : */
2418 340 : stdVacuumCostDelay = VacuumCostDelay;
2419 340 : stdVacuumCostLimit = VacuumCostLimit;
2420 :
2421 : /* Must hold AutovacuumLock while mucking with cost balance info */
2422 340 : LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
2423 :
2424 : /* advertise my cost delay parameters for the balancing algorithm */
2425 340 : MyWorkerInfo->wi_dobalance = tab->at_dobalance;
2426 340 : MyWorkerInfo->wi_cost_delay = tab->at_vacuum_cost_delay;
2427 340 : MyWorkerInfo->wi_cost_limit = tab->at_vacuum_cost_limit;
2428 340 : MyWorkerInfo->wi_cost_limit_base = tab->at_vacuum_cost_limit;
2429 :
2430 : /* do a balance */
2431 340 : autovac_balance_cost();
2432 :
2433 : /* set the active cost parameters from the result of that */
2434 340 : AutoVacuumUpdateDelay();
2435 :
2436 : /* done */
2437 340 : LWLockRelease(AutovacuumLock);
2438 :
2439 : /* clean up memory before each iteration */
2440 340 : MemoryContextResetAndDeleteChildren(PortalContext);
2441 :
2442 : /*
2443 : * Save the relation name for a possible error message, to avoid a
2444 : * catalog lookup in case of an error. If any of these return NULL,
2445 : * then the relation has been dropped since last we checked; skip it.
2446 : * Note: they must live in a long-lived memory context because we call
2447 : * vacuum and analyze in different transactions.
2448 : */
2449 :
2450 340 : tab->at_relname = get_rel_name(tab->at_relid);
2451 340 : tab->at_nspname = get_namespace_name(get_rel_namespace(tab->at_relid));
2452 340 : tab->at_datname = get_database_name(MyDatabaseId);
2453 340 : if (!tab->at_relname || !tab->at_nspname || !tab->at_datname)
2454 : goto deleted;
2455 :
2456 : /*
2457 : * We will abort vacuuming the current table if something errors out,
2458 : * and continue with the next one in schedule; in particular, this
2459 : * happens if we are interrupted with SIGINT.
2460 : */
2461 340 : PG_TRY();
2462 : {
2463 : /* Use PortalContext for any per-table allocations */
2464 340 : MemoryContextSwitchTo(PortalContext);
2465 :
2466 : /* have at it */
2467 340 : autovacuum_do_vac_analyze(tab, bstrategy);
2468 :
2469 : /*
2470 : * Clear a possible query-cancel signal, to avoid a late reaction
2471 : * to an automatically-sent signal because of vacuuming the
2472 : * current table (we're done with it, so it would make no sense to
2473 : * cancel at this point.)
2474 : */
2475 340 : QueryCancelPending = false;
2476 : }
2477 0 : PG_CATCH();
2478 : {
2479 : /*
2480 : * Abort the transaction, start a new one, and proceed with the
2481 : * next table in our list.
2482 : */
2483 0 : HOLD_INTERRUPTS();
2484 0 : if (tab->at_params.options & VACOPT_VACUUM)
2485 0 : errcontext("automatic vacuum of table \"%s.%s.%s\"",
2486 : tab->at_datname, tab->at_nspname, tab->at_relname);
2487 : else
2488 0 : errcontext("automatic analyze of table \"%s.%s.%s\"",
2489 : tab->at_datname, tab->at_nspname, tab->at_relname);
2490 0 : EmitErrorReport();
2491 :
2492 : /* this resets the PGXACT flags too */
2493 0 : AbortOutOfAnyTransaction();
2494 0 : FlushErrorState();
2495 0 : MemoryContextResetAndDeleteChildren(PortalContext);
2496 :
2497 : /* restart our transaction for the following operations */
2498 0 : StartTransactionCommand();
2499 0 : RESUME_INTERRUPTS();
2500 : }
2501 340 : PG_END_TRY();
2502 :
2503 : /* Make sure we're back in AutovacMemCxt */
2504 340 : MemoryContextSwitchTo(AutovacMemCxt);
2505 :
2506 340 : did_vacuum = true;
2507 :
2508 : /* the PGXACT flags are reset at the next end of transaction */
2509 :
2510 : /* be tidy */
2511 : deleted:
2512 340 : if (tab->at_datname != NULL)
2513 340 : pfree(tab->at_datname);
2514 340 : if (tab->at_nspname != NULL)
2515 340 : pfree(tab->at_nspname);
2516 340 : if (tab->at_relname != NULL)
2517 340 : pfree(tab->at_relname);
2518 340 : pfree(tab);
2519 :
2520 : /*
2521 : * Remove my info from shared memory. We could, but intentionally
2522 : * don't, clear wi_cost_limit and friends --- this is on the
2523 : * assumption that we probably have more to do with similar cost
2524 : * settings, so we don't want to give up our share of I/O for a very
2525 : * short interval and thereby thrash the global balance.
2526 : */
2527 340 : LWLockAcquire(AutovacuumScheduleLock, LW_EXCLUSIVE);
2528 340 : MyWorkerInfo->wi_tableoid = InvalidOid;
2529 340 : MyWorkerInfo->wi_sharedrel = false;
2530 340 : LWLockRelease(AutovacuumScheduleLock);
2531 :
2532 : /* restore vacuum cost GUCs for the next iteration */
2533 340 : VacuumCostDelay = stdVacuumCostDelay;
2534 340 : VacuumCostLimit = stdVacuumCostLimit;
2535 : }
2536 :
2537 : /*
2538 : * Perform additional work items, as requested by backends.
2539 : */
2540 60 : LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
2541 15420 : for (i = 0; i < NUM_WORKITEMS; i++)
2542 : {
2543 15360 : AutoVacuumWorkItem *workitem = &AutoVacuumShmem->av_workItems[i];
2544 :
2545 15360 : if (!workitem->avw_used)
2546 15354 : continue;
2547 6 : if (workitem->avw_active)
2548 0 : continue;
2549 6 : if (workitem->avw_database != MyDatabaseId)
2550 0 : continue;
2551 :
2552 : /* claim this one, and release lock while performing it */
2553 6 : workitem->avw_active = true;
2554 6 : LWLockRelease(AutovacuumLock);
2555 :
2556 6 : perform_work_item(workitem);
2557 :
2558 : /*
2559 : * Check for config changes before acquiring lock for further jobs.
2560 : */
2561 6 : CHECK_FOR_INTERRUPTS();
2562 6 : if (got_SIGHUP)
2563 : {
2564 0 : got_SIGHUP = false;
2565 0 : ProcessConfigFile(PGC_SIGHUP);
2566 : }
2567 :
2568 6 : LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
2569 :
2570 : /* and mark it done */
2571 6 : workitem->avw_active = false;
2572 6 : workitem->avw_used = false;
2573 : }
2574 60 : LWLockRelease(AutovacuumLock);
2575 :
2576 : /*
2577 : * We leak table_toast_map here (among other things), but since we're
2578 : * going away soon, it's not a problem.
2579 : */
2580 :
2581 : /*
2582 : * Update pg_database.datfrozenxid, and truncate pg_xact if possible. We
2583 : * only need to do this once, not after each table.
2584 : *
2585 : * Even if we didn't vacuum anything, it may still be important to do
2586 : * this, because one indirect effect of vac_update_datfrozenxid() is to
2587 : * update ShmemVariableCache->xidVacLimit. That might need to be done
2588 : * even if we haven't vacuumed anything, because relations with older
2589 : * relfrozenxid values or other databases with older datfrozenxid values
2590 : * might have been dropped, allowing xidVacLimit to advance.
2591 : *
2592 : * However, it's also important not to do this blindly in all cases,
2593 : * because when autovacuum=off this will restart the autovacuum launcher.
2594 : * If we're not careful, an infinite loop can result, where workers find
2595 : * no work to do and restart the launcher, which starts another worker in
2596 : * the same database that finds no work to do. To prevent that, we skip
2597 : * this if (1) we found no work to do and (2) we skipped at least one
2598 : * table due to concurrent autovacuum activity. In that case, the other
2599 : * worker has already done it, or will do so when it finishes.
2600 : */
2601 60 : if (did_vacuum || !found_concurrent_worker)
2602 60 : vac_update_datfrozenxid();
2603 :
2604 : /* Finally close out the last transaction. */
2605 60 : CommitTransactionCommand();
2606 60 : }
2607 :
2608 : /*
2609 : * Execute a previously registered work item.
2610 : */
2611 : static void
2612 6 : perform_work_item(AutoVacuumWorkItem *workitem)
2613 : {
2614 6 : char *cur_datname = NULL;
2615 6 : char *cur_nspname = NULL;
2616 6 : char *cur_relname = NULL;
2617 :
2618 : /*
2619 : * Note we do not store table info in MyWorkerInfo, since this is not
2620 : * vacuuming proper.
2621 : */
2622 :
2623 : /*
2624 : * Save the relation name for a possible error message, to avoid a catalog
2625 : * lookup in case of an error. If any of these return NULL, then the
2626 : * relation has been dropped since last we checked; skip it.
2627 : */
2628 : Assert(CurrentMemoryContext == AutovacMemCxt);
2629 :
2630 6 : cur_relname = get_rel_name(workitem->avw_relation);
2631 6 : cur_nspname = get_namespace_name(get_rel_namespace(workitem->avw_relation));
2632 6 : cur_datname = get_database_name(MyDatabaseId);
2633 6 : if (!cur_relname || !cur_nspname || !cur_datname)
2634 : goto deleted2;
2635 :
2636 6 : autovac_report_workitem(workitem, cur_nspname, cur_relname);
2637 :
2638 : /* clean up memory before each work item */
2639 6 : MemoryContextResetAndDeleteChildren(PortalContext);
2640 :
2641 : /*
2642 : * We will abort the current work item if something errors out, and
2643 : * continue with the next one; in particular, this happens if we are
2644 : * interrupted with SIGINT. Note that this means that the work item list
2645 : * can be lossy.
2646 : */
2647 6 : PG_TRY();
2648 : {
2649 : /* Use PortalContext for any per-work-item allocations */
2650 6 : MemoryContextSwitchTo(PortalContext);
2651 :
2652 : /* have at it */
2653 6 : switch (workitem->avw_type)
2654 : {
2655 : case AVW_BRINSummarizeRange:
2656 6 : DirectFunctionCall2(brin_summarize_range,
2657 : ObjectIdGetDatum(workitem->avw_relation),
2658 : Int64GetDatum((int64) workitem->avw_blockNumber));
2659 6 : break;
2660 : default:
2661 0 : elog(WARNING, "unrecognized work item found: type %d",
2662 : workitem->avw_type);
2663 0 : break;
2664 : }
2665 :
2666 : /*
2667 : * Clear a possible query-cancel signal, to avoid a late reaction to
2668 : * an automatically-sent signal because of vacuuming the current table
2669 : * (we're done with it, so it would make no sense to cancel at this
2670 : * point.)
2671 : */
2672 6 : QueryCancelPending = false;
2673 : }
2674 0 : PG_CATCH();
2675 : {
2676 : /*
2677 : * Abort the transaction, start a new one, and proceed with the next
2678 : * table in our list.
2679 : */
2680 0 : HOLD_INTERRUPTS();
2681 0 : errcontext("processing work entry for relation \"%s.%s.%s\"",
2682 : cur_datname, cur_nspname, cur_relname);
2683 0 : EmitErrorReport();
2684 :
2685 : /* this resets the PGXACT flags too */
2686 0 : AbortOutOfAnyTransaction();
2687 0 : FlushErrorState();
2688 0 : MemoryContextResetAndDeleteChildren(PortalContext);
2689 :
2690 : /* restart our transaction for the following operations */
2691 0 : StartTransactionCommand();
2692 0 : RESUME_INTERRUPTS();
2693 : }
2694 6 : PG_END_TRY();
2695 :
2696 : /* Make sure we're back in AutovacMemCxt */
2697 6 : MemoryContextSwitchTo(AutovacMemCxt);
2698 :
2699 : /* We intentionally do not set did_vacuum here */
2700 :
2701 : /* be tidy */
2702 : deleted2:
2703 6 : if (cur_datname)
2704 6 : pfree(cur_datname);
2705 6 : if (cur_nspname)
2706 6 : pfree(cur_nspname);
2707 6 : if (cur_relname)
2708 6 : pfree(cur_relname);
2709 6 : }
2710 :
2711 : /*
2712 : * extract_autovac_opts
2713 : *
2714 : * Given a relation's pg_class tuple, return the AutoVacOpts portion of
2715 : * reloptions, if set; otherwise, return NULL.
2716 : */
2717 : static AutoVacOpts *
2718 9162 : extract_autovac_opts(HeapTuple tup, TupleDesc pg_class_desc)
2719 : {
2720 : bytea *relopts;
2721 : AutoVacOpts *av;
2722 :
2723 : Assert(((Form_pg_class) GETSTRUCT(tup))->relkind == RELKIND_RELATION ||
2724 : ((Form_pg_class) GETSTRUCT(tup))->relkind == RELKIND_MATVIEW ||
2725 : ((Form_pg_class) GETSTRUCT(tup))->relkind == RELKIND_TOASTVALUE);
2726 :
2727 9162 : relopts = extractRelOptions(tup, pg_class_desc, NULL);
2728 9162 : if (relopts == NULL)
2729 9128 : return NULL;
2730 :
2731 34 : av = palloc(sizeof(AutoVacOpts));
2732 34 : memcpy(av, &(((StdRdOptions *) relopts)->autovacuum), sizeof(AutoVacOpts));
2733 34 : pfree(relopts);
2734 :
2735 34 : return av;
2736 : }
2737 :
2738 : /*
2739 : * get_pgstat_tabentry_relid
2740 : *
2741 : * Fetch the pgstat entry of a table, either local to a database or shared.
2742 : */
2743 : static PgStat_StatTabEntry *
2744 9162 : get_pgstat_tabentry_relid(Oid relid, bool isshared, PgStat_StatDBEntry *shared,
2745 : PgStat_StatDBEntry *dbentry)
2746 : {
2747 9162 : PgStat_StatTabEntry *tabentry = NULL;
2748 :
2749 9162 : if (isshared)
2750 : {
2751 1224 : if (PointerIsValid(shared))
2752 1224 : tabentry = hash_search(shared->tables, &relid,
2753 : HASH_FIND, NULL);
2754 : }
2755 7938 : else if (PointerIsValid(dbentry))
2756 7938 : tabentry = hash_search(dbentry->tables, &relid,
2757 : HASH_FIND, NULL);
2758 :
2759 9162 : return tabentry;
2760 : }
2761 :
2762 : /*
2763 : * table_recheck_autovac
2764 : *
2765 : * Recheck whether a table still needs vacuum or analyze. Return value is a
2766 : * valid autovac_table pointer if it does, NULL otherwise.
2767 : *
2768 : * Note that the returned autovac_table does not have the name fields set.
2769 : */
2770 : static autovac_table *
2771 340 : table_recheck_autovac(Oid relid, HTAB *table_toast_map,
2772 : TupleDesc pg_class_desc,
2773 : int effective_multixact_freeze_max_age)
2774 : {
2775 : Form_pg_class classForm;
2776 : HeapTuple classTup;
2777 : bool dovacuum;
2778 : bool doanalyze;
2779 340 : autovac_table *tab = NULL;
2780 : PgStat_StatTabEntry *tabentry;
2781 : PgStat_StatDBEntry *shared;
2782 : PgStat_StatDBEntry *dbentry;
2783 : bool wraparound;
2784 : AutoVacOpts *avopts;
2785 :
2786 : /* use fresh stats */
2787 340 : autovac_refresh_stats();
2788 :
2789 340 : shared = pgstat_fetch_stat_dbentry(InvalidOid);
2790 340 : dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
2791 :
2792 : /* fetch the relation's relcache entry */
2793 340 : classTup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
2794 340 : if (!HeapTupleIsValid(classTup))
2795 0 : return NULL;
2796 340 : classForm = (Form_pg_class) GETSTRUCT(classTup);
2797 :
2798 : /*
2799 : * Get the applicable reloptions. If it is a TOAST table, try to get the
2800 : * main table reloptions if the toast table itself doesn't have.
2801 : */
2802 340 : avopts = extract_autovac_opts(classTup, pg_class_desc);
2803 340 : if (classForm->relkind == RELKIND_TOASTVALUE &&
2804 0 : avopts == NULL && table_toast_map != NULL)
2805 : {
2806 : av_relation *hentry;
2807 : bool found;
2808 :
2809 0 : hentry = hash_search(table_toast_map, &relid, HASH_FIND, &found);
2810 0 : if (found && hentry->ar_hasrelopts)
2811 0 : avopts = &hentry->ar_reloptions;
2812 : }
2813 :
2814 : /* fetch the pgstat table entry */
2815 340 : tabentry = get_pgstat_tabentry_relid(relid, classForm->relisshared,
2816 : shared, dbentry);
2817 :
2818 340 : relation_needs_vacanalyze(relid, avopts, classForm, tabentry,
2819 : effective_multixact_freeze_max_age,
2820 : &dovacuum, &doanalyze, &wraparound);
2821 :
2822 : /* ignore ANALYZE for toast tables */
2823 340 : if (classForm->relkind == RELKIND_TOASTVALUE)
2824 0 : doanalyze = false;
2825 :
2826 : /* OK, it needs something done */
2827 340 : if (doanalyze || dovacuum)
2828 : {
2829 : int freeze_min_age;
2830 : int freeze_table_age;
2831 : int multixact_freeze_min_age;
2832 : int multixact_freeze_table_age;
2833 : int vac_cost_limit;
2834 : double vac_cost_delay;
2835 : int log_min_duration;
2836 :
2837 : /*
2838 : * Calculate the vacuum cost parameters and the freeze ages. If there
2839 : * are options set in pg_class.reloptions, use them; in the case of a
2840 : * toast table, try the main table too. Otherwise use the GUC
2841 : * defaults, autovacuum's own first and plain vacuum second.
2842 : */
2843 :
2844 : /* -1 in autovac setting means use plain vacuum_cost_delay */
2845 348 : vac_cost_delay = (avopts && avopts->vacuum_cost_delay >= 0)
2846 : ? avopts->vacuum_cost_delay
2847 680 : : (autovacuum_vac_cost_delay >= 0)
2848 : ? autovacuum_vac_cost_delay
2849 340 : : VacuumCostDelay;
2850 :
2851 : /* 0 or -1 in autovac setting means use plain vacuum_cost_limit */
2852 348 : vac_cost_limit = (avopts && avopts->vacuum_cost_limit > 0)
2853 : ? avopts->vacuum_cost_limit
2854 680 : : (autovacuum_vac_cost_limit > 0)
2855 : ? autovacuum_vac_cost_limit
2856 340 : : VacuumCostLimit;
2857 :
2858 : /* -1 in autovac setting means use log_autovacuum_min_duration */
2859 348 : log_min_duration = (avopts && avopts->log_min_duration >= 0)
2860 : ? avopts->log_min_duration
2861 340 : : Log_autovacuum_min_duration;
2862 :
2863 : /* these do not have autovacuum-specific settings */
2864 348 : freeze_min_age = (avopts && avopts->freeze_min_age >= 0)
2865 : ? avopts->freeze_min_age
2866 340 : : default_freeze_min_age;
2867 :
2868 348 : freeze_table_age = (avopts && avopts->freeze_table_age >= 0)
2869 : ? avopts->freeze_table_age
2870 340 : : default_freeze_table_age;
2871 :
2872 348 : multixact_freeze_min_age = (avopts &&
2873 8 : avopts->multixact_freeze_min_age >= 0)
2874 : ? avopts->multixact_freeze_min_age
2875 340 : : default_multixact_freeze_min_age;
2876 :
2877 348 : multixact_freeze_table_age = (avopts &&
2878 8 : avopts->multixact_freeze_table_age >= 0)
2879 : ? avopts->multixact_freeze_table_age
2880 340 : : default_multixact_freeze_table_age;
2881 :
2882 340 : tab = palloc(sizeof(autovac_table));
2883 340 : tab->at_relid = relid;
2884 340 : tab->at_sharedrel = classForm->relisshared;
2885 680 : tab->at_params.options = VACOPT_SKIPTOAST |
2886 680 : (dovacuum ? VACOPT_VACUUM : 0) |
2887 680 : (doanalyze ? VACOPT_ANALYZE : 0) |
2888 340 : (!wraparound ? VACOPT_SKIP_LOCKED : 0);
2889 340 : tab->at_params.index_cleanup = VACOPT_TERNARY_DEFAULT;
2890 340 : tab->at_params.truncate = VACOPT_TERNARY_DEFAULT;
2891 340 : tab->at_params.freeze_min_age = freeze_min_age;
2892 340 : tab->at_params.freeze_table_age = freeze_table_age;
2893 340 : tab->at_params.multixact_freeze_min_age = multixact_freeze_min_age;
2894 340 : tab->at_params.multixact_freeze_table_age = multixact_freeze_table_age;
2895 340 : tab->at_params.is_wraparound = wraparound;
2896 340 : tab->at_params.log_min_duration = log_min_duration;
2897 340 : tab->at_vacuum_cost_limit = vac_cost_limit;
2898 340 : tab->at_vacuum_cost_delay = vac_cost_delay;
2899 340 : tab->at_relname = NULL;
2900 340 : tab->at_nspname = NULL;
2901 340 : tab->at_datname = NULL;
2902 :
2903 : /*
2904 : * If any of the cost delay parameters has been set individually for
2905 : * this table, disable the balancing algorithm.
2906 : */
2907 340 : tab->at_dobalance =
2908 348 : !(avopts && (avopts->vacuum_cost_limit > 0 ||
2909 8 : avopts->vacuum_cost_delay > 0));
2910 : }
2911 :
2912 340 : heap_freetuple(classTup);
2913 :
2914 340 : return tab;
2915 : }
2916 :
2917 : /*
2918 : * relation_needs_vacanalyze
2919 : *
2920 : * Check whether a relation needs to be vacuumed or analyzed; return each into
2921 : * "dovacuum" and "doanalyze", respectively. Also return whether the vacuum is
2922 : * being forced because of Xid or multixact wraparound.
2923 : *
2924 : * relopts is a pointer to the AutoVacOpts options (either for itself in the
2925 : * case of a plain table, or for either itself or its parent table in the case
2926 : * of a TOAST table), NULL if none; tabentry is the pgstats entry, which can be
2927 : * NULL.
2928 : *
2929 : * A table needs to be vacuumed if the number of dead tuples exceeds a
2930 : * threshold. This threshold is calculated as
2931 : *
2932 : * threshold = vac_base_thresh + vac_scale_factor * reltuples
2933 : *
2934 : * For analyze, the analysis done is that the number of tuples inserted,
2935 : * deleted and updated since the last analyze exceeds a threshold calculated
2936 : * in the same fashion as above. Note that the collector actually stores
2937 : * the number of tuples (both live and dead) that there were as of the last
2938 : * analyze. This is asymmetric to the VACUUM case.
2939 : *
2940 : * We also force vacuum if the table's relfrozenxid is more than freeze_max_age
2941 : * transactions back, and if its relminmxid is more than
2942 : * multixact_freeze_max_age multixacts back.
2943 : *
2944 : * A table whose autovacuum_enabled option is false is
2945 : * automatically skipped (unless we have to vacuum it due to freeze_max_age).
2946 : * Thus autovacuum can be disabled for specific tables. Also, when the stats
2947 : * collector does not have data about a table, it will be skipped.
2948 : *
2949 : * A table whose vac_base_thresh value is < 0 takes the base value from the
2950 : * autovacuum_vacuum_threshold GUC variable. Similarly, a vac_scale_factor
2951 : * value < 0 is substituted with the value of
2952 : * autovacuum_vacuum_scale_factor GUC variable. Ditto for analyze.
2953 : */
2954 : static void
2955 9162 : relation_needs_vacanalyze(Oid relid,
2956 : AutoVacOpts *relopts,
2957 : Form_pg_class classForm,
2958 : PgStat_StatTabEntry *tabentry,
2959 : int effective_multixact_freeze_max_age,
2960 : /* output params below */
2961 : bool *dovacuum,
2962 : bool *doanalyze,
2963 : bool *wraparound)
2964 : {
2965 : bool force_vacuum;
2966 : bool av_enabled;
2967 : float4 reltuples; /* pg_class.reltuples */
2968 :
2969 : /* constants from reloptions or GUC variables */
2970 : int vac_base_thresh,
2971 : anl_base_thresh;
2972 : float4 vac_scale_factor,
2973 : anl_scale_factor;
2974 :
2975 : /* thresholds calculated from above constants */
2976 : float4 vacthresh,
2977 : anlthresh;
2978 :
2979 : /* number of vacuum (resp. analyze) tuples at this time */
2980 : float4 vactuples,
2981 : anltuples;
2982 :
2983 : /* freeze parameters */
2984 : int freeze_max_age;
2985 : int multixact_freeze_max_age;
2986 : TransactionId xidForceLimit;
2987 : MultiXactId multiForceLimit;
2988 :
2989 : AssertArg(classForm != NULL);
2990 : AssertArg(OidIsValid(relid));
2991 :
2992 : /*
2993 : * Determine vacuum/analyze equation parameters. We have two possible
2994 : * sources: the passed reloptions (which could be a main table or a toast
2995 : * table), or the autovacuum GUC variables.
2996 : */
2997 :
2998 : /* -1 in autovac setting means use plain vacuum_scale_factor */
2999 9214 : vac_scale_factor = (relopts && relopts->vacuum_scale_factor >= 0)
3000 0 : ? relopts->vacuum_scale_factor
3001 9162 : : autovacuum_vac_scale;
3002 :
3003 9214 : vac_base_thresh = (relopts && relopts->vacuum_threshold >= 0)
3004 : ? relopts->vacuum_threshold
3005 9162 : : autovacuum_vac_thresh;
3006 :
3007 9214 : anl_scale_factor = (relopts && relopts->analyze_scale_factor >= 0)
3008 0 : ? relopts->analyze_scale_factor
3009 9162 : : autovacuum_anl_scale;
3010 :
3011 9214 : anl_base_thresh = (relopts && relopts->analyze_threshold >= 0)
3012 : ? relopts->analyze_threshold
3013 9162 : : autovacuum_anl_thresh;
3014 :
3015 9214 : freeze_max_age = (relopts && relopts->freeze_max_age >= 0)
3016 0 : ? Min(relopts->freeze_max_age, autovacuum_freeze_max_age)
3017 9162 : : autovacuum_freeze_max_age;
3018 :
3019 9214 : multixact_freeze_max_age = (relopts && relopts->multixact_freeze_max_age >= 0)
3020 0 : ? Min(relopts->multixact_freeze_max_age, effective_multixact_freeze_max_age)
3021 9162 : : effective_multixact_freeze_max_age;
3022 :
3023 9162 : av_enabled = (relopts ? relopts->enabled : true);
3024 :
3025 : /* Force vacuum if table is at risk of wraparound */
3026 9162 : xidForceLimit = recentXid - freeze_max_age;
3027 9162 : if (xidForceLimit < FirstNormalTransactionId)
3028 0 : xidForceLimit -= FirstNormalTransactionId;
3029 18324 : force_vacuum = (TransactionIdIsNormal(classForm->relfrozenxid) &&
3030 9162 : TransactionIdPrecedes(classForm->relfrozenxid,
3031 : xidForceLimit));
3032 9162 : if (!force_vacuum)
3033 : {
3034 9162 : multiForceLimit = recentMulti - multixact_freeze_max_age;
3035 9162 : if (multiForceLimit < FirstMultiXactId)
3036 0 : multiForceLimit -= FirstMultiXactId;
3037 18324 : force_vacuum = MultiXactIdIsValid(classForm->relminmxid) &&
3038 9162 : MultiXactIdPrecedes(classForm->relminmxid, multiForceLimit);
3039 : }
3040 9162 : *wraparound = force_vacuum;
3041 :
3042 : /* User disabled it in pg_class.reloptions? (But ignore if at risk) */
3043 9162 : if (!av_enabled && !force_vacuum)
3044 : {
3045 18 : *doanalyze = false;
3046 18 : *dovacuum = false;
3047 18 : return;
3048 : }
3049 :
3050 : /*
3051 : * If we found the table in the stats hash, and autovacuum is currently
3052 : * enabled, make a threshold-based decision whether to vacuum and/or
3053 : * analyze. If autovacuum is currently disabled, we must be here for
3054 : * anti-wraparound vacuuming only, so don't vacuum (or analyze) anything
3055 : * that's not being forced.
3056 : */
3057 9144 : if (PointerIsValid(tabentry) && AutoVacuumingActive())
3058 : {
3059 4774 : reltuples = classForm->reltuples;
3060 4774 : vactuples = tabentry->n_dead_tuples;
3061 4774 : anltuples = tabentry->changes_since_analyze;
3062 :
3063 4774 : vacthresh = (float4) vac_base_thresh + vac_scale_factor * reltuples;
3064 4774 : anlthresh = (float4) anl_base_thresh + anl_scale_factor * reltuples;
3065 :
3066 : /*
3067 : * Note that we don't need to take special consideration for stat
3068 : * reset, because if that happens, the last vacuum and analyze counts
3069 : * will be reset too.
3070 : */
3071 4774 : elog(DEBUG3, "%s: vac: %.0f (threshold %.0f), anl: %.0f (threshold %.0f)",
3072 : NameStr(classForm->relname),
3073 : vactuples, vacthresh, anltuples, anlthresh);
3074 :
3075 : /* Determine if this table needs vacuum or analyze. */
3076 4774 : *dovacuum = force_vacuum || (vactuples > vacthresh);
3077 4774 : *doanalyze = (anltuples > anlthresh);
3078 : }
3079 : else
3080 : {
3081 : /*
3082 : * Skip a table not found in stat hash, unless we have to force vacuum
3083 : * for anti-wrap purposes. If it's not acted upon, there's no need to
3084 : * vacuum it.
3085 : */
3086 4370 : *dovacuum = force_vacuum;
3087 4370 : *doanalyze = false;
3088 : }
3089 :
3090 : /* ANALYZE refuses to work with pg_statistic */
3091 9144 : if (relid == StatisticRelationId)
3092 70 : *doanalyze = false;
3093 : }
3094 :
3095 : /*
3096 : * autovacuum_do_vac_analyze
3097 : * Vacuum and/or analyze the specified table
3098 : */
3099 : static void
3100 340 : autovacuum_do_vac_analyze(autovac_table *tab, BufferAccessStrategy bstrategy)
3101 : {
3102 : RangeVar *rangevar;
3103 : VacuumRelation *rel;
3104 : List *rel_list;
3105 :
3106 : /* Let pgstat know what we're doing */
3107 340 : autovac_report_activity(tab);
3108 :
3109 : /* Set up one VacuumRelation target, identified by OID, for vacuum() */
3110 340 : rangevar = makeRangeVar(tab->at_nspname, tab->at_relname, -1);
3111 340 : rel = makeVacuumRelation(rangevar, tab->at_relid, NIL);
3112 340 : rel_list = list_make1(rel);
3113 :
3114 340 : vacuum(rel_list, &tab->at_params, bstrategy, true);
3115 340 : }
3116 :
3117 : /*
3118 : * autovac_report_activity
3119 : * Report to pgstat what autovacuum is doing
3120 : *
3121 : * We send a SQL string corresponding to what the user would see if the
3122 : * equivalent command was to be issued manually.
3123 : *
3124 : * Note we assume that we are going to report the next command as soon as we're
3125 : * done with the current one, and exit right after the last one, so we don't
3126 : * bother to report "<IDLE>" or some such.
3127 : */
3128 : static void
3129 340 : autovac_report_activity(autovac_table *tab)
3130 : {
3131 : #define MAX_AUTOVAC_ACTIV_LEN (NAMEDATALEN * 2 + 56)
3132 : char activity[MAX_AUTOVAC_ACTIV_LEN];
3133 : int len;
3134 :
3135 : /* Report the command and possible options */
3136 340 : if (tab->at_params.options & VACOPT_VACUUM)
3137 152 : snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
3138 : "autovacuum: VACUUM%s",
3139 152 : tab->at_params.options & VACOPT_ANALYZE ? " ANALYZE" : "");
3140 : else
3141 188 : snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
3142 : "autovacuum: ANALYZE");
3143 :
3144 : /*
3145 : * Report the qualified name of the relation.
3146 : */
3147 340 : len = strlen(activity);
3148 :
3149 340 : snprintf(activity + len, MAX_AUTOVAC_ACTIV_LEN - len,
3150 : " %s.%s%s", tab->at_nspname, tab->at_relname,
3151 340 : tab->at_params.is_wraparound ? " (to prevent wraparound)" : "");
3152 :
3153 : /* Set statement_timestamp() to current time for pg_stat_activity */
3154 340 : SetCurrentStatementStartTimestamp();
3155 :
3156 340 : pgstat_report_activity(STATE_RUNNING, activity);
3157 340 : }
3158 :
3159 : /*
3160 : * autovac_report_workitem
3161 : * Report to pgstat that autovacuum is processing a work item
3162 : */
3163 : static void
3164 6 : autovac_report_workitem(AutoVacuumWorkItem *workitem,
3165 : const char *nspname, const char *relname)
3166 : {
3167 : char activity[MAX_AUTOVAC_ACTIV_LEN + 12 + 2];
3168 : char blk[12 + 2];
3169 : int len;
3170 :
3171 6 : switch (workitem->avw_type)
3172 : {
3173 : case AVW_BRINSummarizeRange:
3174 6 : snprintf(activity, MAX_AUTOVAC_ACTIV_LEN,
3175 : "autovacuum: BRIN summarize");
3176 6 : break;
3177 : }
3178 :
3179 : /*
3180 : * Report the qualified name of the relation, and the block number if any
3181 : */
3182 6 : len = strlen(activity);
3183 :
3184 6 : if (BlockNumberIsValid(workitem->avw_blockNumber))
3185 6 : snprintf(blk, sizeof(blk), " %u", workitem->avw_blockNumber);
3186 : else
3187 0 : blk[0] = '\0';
3188 :
3189 6 : snprintf(activity + len, MAX_AUTOVAC_ACTIV_LEN - len,
3190 : " %s.%s%s", nspname, relname, blk);
3191 :
3192 : /* Set statement_timestamp() to current time for pg_stat_activity */
3193 6 : SetCurrentStatementStartTimestamp();
3194 :
3195 6 : pgstat_report_activity(STATE_RUNNING, activity);
3196 6 : }
3197 :
3198 : /*
3199 : * AutoVacuumingActive
3200 : * Check GUC vars and report whether the autovacuum process should be
3201 : * running.
3202 : */
3203 : bool
3204 8368 : AutoVacuumingActive(void)
3205 : {
3206 8368 : if (!autovacuum_start_daemon || !pgstat_track_counts)
3207 222 : return false;
3208 8146 : return true;
3209 : }
3210 :
3211 : /*
3212 : * Request one work item to the next autovacuum run processing our database.
3213 : * Return false if the request can't be recorded.
3214 : */
3215 : bool
3216 6 : AutoVacuumRequestWork(AutoVacuumWorkItemType type, Oid relationId,
3217 : BlockNumber blkno)
3218 : {
3219 : int i;
3220 6 : bool result = false;
3221 :
3222 6 : LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
3223 :
3224 : /*
3225 : * Locate an unused work item and fill it with the given data.
3226 : */
3227 24 : for (i = 0; i < NUM_WORKITEMS; i++)
3228 : {
3229 12 : AutoVacuumWorkItem *workitem = &AutoVacuumShmem->av_workItems[i];
3230 :
3231 12 : if (workitem->avw_used)
3232 6 : continue;
3233 :
3234 6 : workitem->avw_used = true;
3235 6 : workitem->avw_active = false;
3236 6 : workitem->avw_type = type;
3237 6 : workitem->avw_database = MyDatabaseId;
3238 6 : workitem->avw_relation = relationId;
3239 6 : workitem->avw_blockNumber = blkno;
3240 6 : result = true;
3241 :
3242 : /* done */
3243 6 : break;
3244 : }
3245 :
3246 6 : LWLockRelease(AutovacuumLock);
3247 :
3248 6 : return result;
3249 : }
3250 :
3251 : /*
3252 : * autovac_init
3253 : * This is called at postmaster initialization.
3254 : *
3255 : * All we do here is annoy the user if he got it wrong.
3256 : */
3257 : void
3258 572 : autovac_init(void)
3259 : {
3260 572 : if (autovacuum_start_daemon && !pgstat_track_counts)
3261 0 : ereport(WARNING,
3262 : (errmsg("autovacuum not started because of misconfiguration"),
3263 : errhint("Enable the \"track_counts\" option.")));
3264 572 : }
3265 :
3266 : /*
3267 : * IsAutoVacuum functions
3268 : * Return whether this is either a launcher autovacuum process or a worker
3269 : * process.
3270 : */
3271 : bool
3272 55358 : IsAutoVacuumLauncherProcess(void)
3273 : {
3274 55358 : return am_autovacuum_launcher;
3275 : }
3276 :
3277 : bool
3278 267858 : IsAutoVacuumWorkerProcess(void)
3279 : {
3280 267858 : return am_autovacuum_worker;
3281 : }
3282 :
3283 :
3284 : /*
3285 : * AutoVacuumShmemSize
3286 : * Compute space needed for autovacuum-related shared memory
3287 : */
3288 : Size
3289 3700 : AutoVacuumShmemSize(void)
3290 : {
3291 : Size size;
3292 :
3293 : /*
3294 : * Need the fixed struct and the array of WorkerInfoData.
3295 : */
3296 3700 : size = sizeof(AutoVacuumShmemStruct);
3297 3700 : size = MAXALIGN(size);
3298 3700 : size = add_size(size, mul_size(autovacuum_max_workers,
3299 : sizeof(WorkerInfoData)));
3300 3700 : return size;
3301 : }
3302 :
3303 : /*
3304 : * AutoVacuumShmemInit
3305 : * Allocate and initialize autovacuum-related shared memory
3306 : */
3307 : void
3308 1848 : AutoVacuumShmemInit(void)
3309 : {
3310 : bool found;
3311 :
3312 1848 : AutoVacuumShmem = (AutoVacuumShmemStruct *)
3313 1848 : ShmemInitStruct("AutoVacuum Data",
3314 : AutoVacuumShmemSize(),
3315 : &found);
3316 :
3317 1848 : if (!IsUnderPostmaster)
3318 : {
3319 : WorkerInfo worker;
3320 : int i;
3321 :
3322 : Assert(!found);
3323 :
3324 1848 : AutoVacuumShmem->av_launcherpid = 0;
3325 1848 : dlist_init(&AutoVacuumShmem->av_freeWorkers);
3326 1848 : dlist_init(&AutoVacuumShmem->av_runningWorkers);
3327 1848 : AutoVacuumShmem->av_startingWorker = NULL;
3328 1848 : memset(AutoVacuumShmem->av_workItems, 0,
3329 : sizeof(AutoVacuumWorkItem) * NUM_WORKITEMS);
3330 :
3331 1848 : worker = (WorkerInfo) ((char *) AutoVacuumShmem +
3332 : MAXALIGN(sizeof(AutoVacuumShmemStruct)));
3333 :
3334 : /* initialize the WorkerInfo free list */
3335 7392 : for (i = 0; i < autovacuum_max_workers; i++)
3336 5544 : dlist_push_head(&AutoVacuumShmem->av_freeWorkers,
3337 5544 : &worker[i].wi_links);
3338 : }
3339 : else
3340 : Assert(found);
3341 1848 : }
3342 :
3343 : /*
3344 : * autovac_refresh_stats
3345 : * Refresh pgstats data for an autovacuum process
3346 : *
3347 : * Cause the next pgstats read operation to obtain fresh data, but throttle
3348 : * such refreshing in the autovacuum launcher. This is mostly to avoid
3349 : * rereading the pgstats files too many times in quick succession when there
3350 : * are many databases.
3351 : *
3352 : * Note: we avoid throttling in the autovac worker, as it would be
3353 : * counterproductive in the recheck logic.
3354 : */
3355 : static void
3356 1048 : autovac_refresh_stats(void)
3357 : {
3358 1048 : if (IsAutoVacuumLauncherProcess())
3359 : {
3360 : static TimestampTz last_read = 0;
3361 : TimestampTz current_time;
3362 :
3363 708 : current_time = GetCurrentTimestamp();
3364 :
3365 708 : if (!TimestampDifferenceExceeds(last_read, current_time,
3366 : STATS_READ_DELAY))
3367 308 : return;
3368 :
3369 400 : last_read = current_time;
3370 : }
3371 :
3372 740 : pgstat_clear_snapshot();
3373 : }
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