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launcher.c File Reference
Include dependency graph for launcher.c:

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Data Structures

struct  LogicalRepCtxStruct
 

Macros

#define DEFAULT_NAPTIME_PER_CYCLE   180000L
 
#define PG_STAT_GET_SUBSCRIPTION_COLS   8
 

Typedefs

typedef struct LogicalRepCtxStruct LogicalRepCtxStruct
 

Functions

static void ApplyLauncherWakeup (void)
 
static void logicalrep_launcher_onexit (int code, Datum arg)
 
static void logicalrep_worker_onexit (int code, Datum arg)
 
static void logicalrep_worker_detach (void)
 
static void logicalrep_worker_cleanup (LogicalRepWorker *worker)
 
static Listget_subscription_list (void)
 
static void WaitForReplicationWorkerAttach (LogicalRepWorker *worker, uint16 generation, BackgroundWorkerHandle *handle)
 
LogicalRepWorkerlogicalrep_worker_find (Oid subid, Oid relid, bool only_running)
 
Listlogicalrep_workers_find (Oid subid, bool only_running)
 
void logicalrep_worker_launch (Oid dbid, Oid subid, const char *subname, Oid userid, Oid relid)
 
void logicalrep_worker_stop (Oid subid, Oid relid)
 
void logicalrep_worker_wakeup (Oid subid, Oid relid)
 
void logicalrep_worker_wakeup_ptr (LogicalRepWorker *worker)
 
void logicalrep_worker_attach (int slot)
 
int logicalrep_sync_worker_count (Oid subid)
 
Size ApplyLauncherShmemSize (void)
 
void ApplyLauncherRegister (void)
 
void ApplyLauncherShmemInit (void)
 
void AtEOXact_ApplyLauncher (bool isCommit)
 
void ApplyLauncherWakeupAtCommit (void)
 
void ApplyLauncherMain (Datum main_arg)
 
bool IsLogicalLauncher (void)
 
Datum pg_stat_get_subscription (PG_FUNCTION_ARGS)
 

Variables

int max_logical_replication_workers = 4
 
int max_sync_workers_per_subscription = 2
 
LogicalRepWorkerMyLogicalRepWorker = NULL
 
static LogicalRepCtxStructLogicalRepCtx
 
static bool on_commit_launcher_wakeup = false
 

Macro Definition Documentation

◆ DEFAULT_NAPTIME_PER_CYCLE

#define DEFAULT_NAPTIME_PER_CYCLE   180000L

Definition at line 53 of file launcher.c.

◆ PG_STAT_GET_SUBSCRIPTION_COLS

#define PG_STAT_GET_SUBSCRIPTION_COLS   8

Typedef Documentation

◆ LogicalRepCtxStruct

Function Documentation

◆ ApplyLauncherMain()

void ApplyLauncherMain ( Datum  main_arg)

Definition at line 802 of file launcher.c.

803 {
804  TimestampTz last_start_time = 0;
805 
806  ereport(DEBUG1,
807  (errmsg_internal("logical replication launcher started")));
808 
810 
813 
814  /* Establish signal handlers. */
816  pqsignal(SIGTERM, die);
818 
819  /*
820  * Establish connection to nailed catalogs (we only ever access
821  * pg_subscription).
822  */
824 
825  /* Enter main loop */
826  for (;;)
827  {
828  int rc;
829  List *sublist;
830  ListCell *lc;
831  MemoryContext subctx;
832  MemoryContext oldctx;
834  long wait_time = DEFAULT_NAPTIME_PER_CYCLE;
835 
837 
839 
840  /* Limit the start retry to once a wal_retrieve_retry_interval */
841  if (TimestampDifferenceExceeds(last_start_time, now,
843  {
844  /* Use temporary context for the database list and worker info. */
846  "Logical Replication Launcher sublist",
848  oldctx = MemoryContextSwitchTo(subctx);
849 
850  /* search for subscriptions to start or stop. */
851  sublist = get_subscription_list();
852 
853  /* Start the missing workers for enabled subscriptions. */
854  foreach(lc, sublist)
855  {
856  Subscription *sub = (Subscription *) lfirst(lc);
857  LogicalRepWorker *w;
858 
859  if (!sub->enabled)
860  continue;
861 
862  LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
863  w = logicalrep_worker_find(sub->oid, InvalidOid, false);
864  LWLockRelease(LogicalRepWorkerLock);
865 
866  if (w == NULL)
867  {
868  last_start_time = now;
869  wait_time = wal_retrieve_retry_interval;
870 
871  logicalrep_worker_launch(sub->dbid, sub->oid, sub->name,
872  sub->owner, InvalidOid);
873  }
874  }
875 
876  /* Switch back to original memory context. */
877  MemoryContextSwitchTo(oldctx);
878  /* Clean the temporary memory. */
879  MemoryContextDelete(subctx);
880  }
881  else
882  {
883  /*
884  * The wait in previous cycle was interrupted in less than
885  * wal_retrieve_retry_interval since last worker was started, this
886  * usually means crash of the worker, so we should retry in
887  * wal_retrieve_retry_interval again.
888  */
889  wait_time = wal_retrieve_retry_interval;
890  }
891 
892  /* Wait for more work. */
893  rc = WaitLatch(MyLatch,
895  wait_time,
897 
898  if (rc & WL_LATCH_SET)
899  {
902  }
903 
905  {
906  ConfigReloadPending = false;
908  }
909  }
910 
911  /* Not reachable */
912 }
bool TimestampDifferenceExceeds(TimestampTz start_time, TimestampTz stop_time, int msec)
Definition: timestamp.c:1719
TimestampTz GetCurrentTimestamp(void)
Definition: timestamp.c:1573
Datum now(PG_FUNCTION_ARGS)
Definition: timestamp.c:1537
int64 TimestampTz
Definition: timestamp.h:39
int errmsg_internal(const char *fmt,...)
Definition: elog.c:993
#define DEBUG1
Definition: elog.h:26
#define ereport(elevel,...)
Definition: elog.h:145
int MyProcPid
Definition: globals.c:44
struct Latch * MyLatch
Definition: globals.c:58
@ PGC_SIGHUP
Definition: guc.h:71
void ProcessConfigFile(GucContext context)
volatile sig_atomic_t ConfigReloadPending
Definition: interrupt.c:27
void SignalHandlerForConfigReload(SIGNAL_ARGS)
Definition: interrupt.c:61
void before_shmem_exit(pg_on_exit_callback function, Datum arg)
Definition: ipc.c:333
void ResetLatch(Latch *latch)
Definition: latch.c:683
int WaitLatch(Latch *latch, int wakeEvents, long timeout, uint32 wait_event_info)
Definition: latch.c:476
#define WL_TIMEOUT
Definition: latch.h:128
#define WL_EXIT_ON_PM_DEATH
Definition: latch.h:130
#define WL_LATCH_SET
Definition: latch.h:125
#define DEFAULT_NAPTIME_PER_CYCLE
Definition: launcher.c:53
LogicalRepWorker * logicalrep_worker_find(Oid subid, Oid relid, bool only_running)
Definition: launcher.c:215
static List * get_subscription_list(void)
Definition: launcher.c:88
static void logicalrep_launcher_onexit(int code, Datum arg)
Definition: launcher.c:633
void logicalrep_worker_launch(Oid dbid, Oid subid, const char *subname, Oid userid, Oid relid)
Definition: launcher.c:266
static LogicalRepCtxStruct * LogicalRepCtx
Definition: launcher.c:70
Assert(fmt[strlen(fmt) - 1] !='\n')
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1194
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1802
@ LW_SHARED
Definition: lwlock.h:113
MemoryContext TopMemoryContext
Definition: mcxt.c:130
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:376
#define AllocSetContextCreate
Definition: memutils.h:129
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:153
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:121
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:135
#define lfirst(lc)
Definition: pg_list.h:170
#define die(msg)
Definition: pg_test_fsync.c:95
pqsigfunc pqsignal(int signo, pqsigfunc func)
uintptr_t Datum
Definition: postgres.h:412
#define InvalidOid
Definition: postgres_ext.h:36
void BackgroundWorkerInitializeConnection(const char *dbname, const char *username, uint32 flags)
Definition: postmaster.c:5541
void BackgroundWorkerUnblockSignals(void)
Definition: postmaster.c:5601
Definition: pg_list.h:52
@ WAIT_EVENT_LOGICAL_LAUNCHER_MAIN
Definition: wait_event.h:44
#define SIGHUP
Definition: win32_port.h:176
int wal_retrieve_retry_interval
Definition: xlog.c:137

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, Assert(), BackgroundWorkerInitializeConnection(), BackgroundWorkerUnblockSignals(), before_shmem_exit(), CHECK_FOR_INTERRUPTS, ConfigReloadPending, Subscription::dbid, DEBUG1, DEFAULT_NAPTIME_PER_CYCLE, die, Subscription::enabled, ereport, errmsg_internal(), get_subscription_list(), GetCurrentTimestamp(), InvalidOid, LogicalRepCtxStruct::launcher_pid, lfirst, logicalrep_launcher_onexit(), logicalrep_worker_find(), logicalrep_worker_launch(), LogicalRepCtx, LW_SHARED, LWLockAcquire(), LWLockRelease(), MemoryContextDelete(), MemoryContextSwitchTo(), MyLatch, MyProcPid, Subscription::name, now(), Subscription::oid, Subscription::owner, PGC_SIGHUP, pqsignal(), ProcessConfigFile(), ResetLatch(), SIGHUP, SignalHandlerForConfigReload(), TimestampDifferenceExceeds(), TopMemoryContext, WAIT_EVENT_LOGICAL_LAUNCHER_MAIN, WaitLatch(), wal_retrieve_retry_interval, WL_EXIT_ON_PM_DEATH, WL_LATCH_SET, and WL_TIMEOUT.

◆ ApplyLauncherRegister()

void ApplyLauncherRegister ( void  )

Definition at line 707 of file launcher.c.

708 {
709  BackgroundWorker bgw;
710 
712  return;
713 
714  memset(&bgw, 0, sizeof(bgw));
718  snprintf(bgw.bgw_library_name, BGW_MAXLEN, "postgres");
719  snprintf(bgw.bgw_function_name, BGW_MAXLEN, "ApplyLauncherMain");
721  "logical replication launcher");
723  "logical replication launcher");
724  bgw.bgw_restart_time = 5;
725  bgw.bgw_notify_pid = 0;
726  bgw.bgw_main_arg = (Datum) 0;
727 
729 }
void RegisterBackgroundWorker(BackgroundWorker *worker)
Definition: bgworker.c:872
@ BgWorkerStart_RecoveryFinished
Definition: bgworker.h:81
#define BGWORKER_BACKEND_DATABASE_CONNECTION
Definition: bgworker.h:60
#define BGWORKER_SHMEM_ACCESS
Definition: bgworker.h:53
#define BGW_MAXLEN
Definition: bgworker.h:86
int max_logical_replication_workers
Definition: launcher.c:56
#define snprintf
Definition: port.h:238
char bgw_function_name[BGW_MAXLEN]
Definition: bgworker.h:97
Datum bgw_main_arg
Definition: bgworker.h:98
char bgw_name[BGW_MAXLEN]
Definition: bgworker.h:91
int bgw_restart_time
Definition: bgworker.h:95
char bgw_type[BGW_MAXLEN]
Definition: bgworker.h:92
BgWorkerStartTime bgw_start_time
Definition: bgworker.h:94
pid_t bgw_notify_pid
Definition: bgworker.h:100
char bgw_library_name[BGW_MAXLEN]
Definition: bgworker.h:96

References BackgroundWorker::bgw_flags, BackgroundWorker::bgw_function_name, BackgroundWorker::bgw_library_name, BackgroundWorker::bgw_main_arg, BGW_MAXLEN, BackgroundWorker::bgw_name, BackgroundWorker::bgw_notify_pid, BackgroundWorker::bgw_restart_time, BackgroundWorker::bgw_start_time, BackgroundWorker::bgw_type, BGWORKER_BACKEND_DATABASE_CONNECTION, BGWORKER_SHMEM_ACCESS, BgWorkerStart_RecoveryFinished, max_logical_replication_workers, RegisterBackgroundWorker(), and snprintf.

Referenced by PostmasterMain().

◆ ApplyLauncherShmemInit()

void ApplyLauncherShmemInit ( void  )

Definition at line 736 of file launcher.c.

737 {
738  bool found;
739 
741  ShmemInitStruct("Logical Replication Launcher Data",
743  &found);
744 
745  if (!found)
746  {
747  int slot;
748 
750 
751  /* Initialize memory and spin locks for each worker slot. */
752  for (slot = 0; slot < max_logical_replication_workers; slot++)
753  {
754  LogicalRepWorker *worker = &LogicalRepCtx->workers[slot];
755 
756  memset(worker, 0, sizeof(LogicalRepWorker));
757  SpinLockInit(&worker->relmutex);
758  }
759  }
760 }
Size ApplyLauncherShmemSize(void)
Definition: launcher.c:688
void * ShmemInitStruct(const char *name, Size size, bool *foundPtr)
Definition: shmem.c:396
#define SpinLockInit(lock)
Definition: spin.h:60
LogicalRepWorker workers[FLEXIBLE_ARRAY_MEMBER]
Definition: launcher.c:67

References ApplyLauncherShmemSize(), LogicalRepCtx, max_logical_replication_workers, LogicalRepWorker::relmutex, ShmemInitStruct(), SpinLockInit, and LogicalRepCtxStruct::workers.

Referenced by CreateSharedMemoryAndSemaphores().

◆ ApplyLauncherShmemSize()

Size ApplyLauncherShmemSize ( void  )

Definition at line 688 of file launcher.c.

689 {
690  Size size;
691 
692  /*
693  * Need the fixed struct and the array of LogicalRepWorker.
694  */
695  size = sizeof(LogicalRepCtxStruct);
696  size = MAXALIGN(size);
698  sizeof(LogicalRepWorker)));
699  return size;
700 }
#define MAXALIGN(LEN)
Definition: c.h:747
size_t Size
Definition: c.h:541
struct LogicalRepCtxStruct LogicalRepCtxStruct
Size add_size(Size s1, Size s2)
Definition: shmem.c:502
Size mul_size(Size s1, Size s2)
Definition: shmem.c:519

References add_size(), max_logical_replication_workers, MAXALIGN, and mul_size().

Referenced by ApplyLauncherShmemInit(), and CalculateShmemSize().

◆ ApplyLauncherWakeup()

static void ApplyLauncherWakeup ( void  )
static

Definition at line 792 of file launcher.c.

793 {
794  if (LogicalRepCtx->launcher_pid != 0)
796 }
#define kill(pid, sig)
Definition: win32_port.h:482
#define SIGUSR1
Definition: win32_port.h:188

References kill, LogicalRepCtxStruct::launcher_pid, LogicalRepCtx, and SIGUSR1.

Referenced by AtEOXact_ApplyLauncher(), and logicalrep_worker_onexit().

◆ ApplyLauncherWakeupAtCommit()

void ApplyLauncherWakeupAtCommit ( void  )

Definition at line 785 of file launcher.c.

786 {
789 }
static bool on_commit_launcher_wakeup
Definition: launcher.c:78

References on_commit_launcher_wakeup.

Referenced by AlterSubscription(), AlterSubscriptionOwner_internal(), and CreateSubscription().

◆ AtEOXact_ApplyLauncher()

void AtEOXact_ApplyLauncher ( bool  isCommit)

Definition at line 766 of file launcher.c.

767 {
768  if (isCommit)
769  {
772  }
773 
775 }
static void ApplyLauncherWakeup(void)
Definition: launcher.c:792

References ApplyLauncherWakeup(), and on_commit_launcher_wakeup.

Referenced by AbortTransaction(), and CommitTransaction().

◆ get_subscription_list()

static List* get_subscription_list ( void  )
static

Definition at line 88 of file launcher.c.

89 {
90  List *res = NIL;
91  Relation rel;
92  TableScanDesc scan;
93  HeapTuple tup;
94  MemoryContext resultcxt;
95 
96  /* This is the context that we will allocate our output data in */
97  resultcxt = CurrentMemoryContext;
98 
99  /*
100  * Start a transaction so we can access pg_database, and get a snapshot.
101  * We don't have a use for the snapshot itself, but we're interested in
102  * the secondary effect that it sets RecentGlobalXmin. (This is critical
103  * for anything that reads heap pages, because HOT may decide to prune
104  * them even if the process doesn't attempt to modify any tuples.)
105  *
106  * FIXME: This comment is inaccurate / the code buggy. A snapshot that is
107  * not pushed/active does not reliably prevent HOT pruning (->xmin could
108  * e.g. be cleared when cache invalidations are processed).
109  */
111  (void) GetTransactionSnapshot();
112 
113  rel = table_open(SubscriptionRelationId, AccessShareLock);
114  scan = table_beginscan_catalog(rel, 0, NULL);
115 
117  {
119  Subscription *sub;
120  MemoryContext oldcxt;
121 
122  /*
123  * Allocate our results in the caller's context, not the
124  * transaction's. We do this inside the loop, and restore the original
125  * context at the end, so that leaky things like heap_getnext() are
126  * not called in a potentially long-lived context.
127  */
128  oldcxt = MemoryContextSwitchTo(resultcxt);
129 
130  sub = (Subscription *) palloc0(sizeof(Subscription));
131  sub->oid = subform->oid;
132  sub->dbid = subform->subdbid;
133  sub->owner = subform->subowner;
134  sub->enabled = subform->subenabled;
135  sub->name = pstrdup(NameStr(subform->subname));
136  /* We don't fill fields we are not interested in. */
137 
138  res = lappend(res, sub);
139  MemoryContextSwitchTo(oldcxt);
140  }
141 
142  table_endscan(scan);
144 
146 
147  return res;
148 }
#define NameStr(name)
Definition: c.h:682
HeapTuple heap_getnext(TableScanDesc sscan, ScanDirection direction)
Definition: heapam.c:1299
#define HeapTupleIsValid(tuple)
Definition: htup.h:78
#define GETSTRUCT(TUP)
Definition: htup_details.h:649
List * lappend(List *list, void *datum)
Definition: list.c:338
#define AccessShareLock
Definition: lockdefs.h:36
char * pstrdup(const char *in)
Definition: mcxt.c:1483
void * palloc0(Size size)
Definition: mcxt.c:1230
MemoryContext CurrentMemoryContext
Definition: mcxt.c:124
#define NIL
Definition: pg_list.h:66
FormData_pg_subscription * Form_pg_subscription
@ ForwardScanDirection
Definition: sdir.h:26
Snapshot GetTransactionSnapshot(void)
Definition: snapmgr.c:251
void table_close(Relation relation, LOCKMODE lockmode)
Definition: table.c:126
Relation table_open(Oid relationId, LOCKMODE lockmode)
Definition: table.c:40
TableScanDesc table_beginscan_catalog(Relation relation, int nkeys, struct ScanKeyData *key)
Definition: tableam.c:112
static void table_endscan(TableScanDesc scan)
Definition: tableam.h:993
void StartTransactionCommand(void)
Definition: xact.c:2925
void CommitTransactionCommand(void)
Definition: xact.c:3022

References AccessShareLock, CommitTransactionCommand(), CurrentMemoryContext, Subscription::dbid, Subscription::enabled, ForwardScanDirection, GETSTRUCT, GetTransactionSnapshot(), heap_getnext(), HeapTupleIsValid, lappend(), MemoryContextSwitchTo(), Subscription::name, NameStr, NIL, Subscription::oid, Subscription::owner, palloc0(), pstrdup(), res, StartTransactionCommand(), table_beginscan_catalog(), table_close(), table_endscan(), and table_open().

Referenced by ApplyLauncherMain().

◆ IsLogicalLauncher()

bool IsLogicalLauncher ( void  )

Definition at line 918 of file launcher.c.

919 {
921 }

References LogicalRepCtxStruct::launcher_pid, LogicalRepCtx, and MyProcPid.

Referenced by ProcessInterrupts().

◆ logicalrep_launcher_onexit()

static void logicalrep_launcher_onexit ( int  code,
Datum  arg 
)
static

Definition at line 633 of file launcher.c.

634 {
636 }

References LogicalRepCtxStruct::launcher_pid, and LogicalRepCtx.

Referenced by ApplyLauncherMain().

◆ logicalrep_sync_worker_count()

int logicalrep_sync_worker_count ( Oid  subid)

Definition at line 664 of file launcher.c.

665 {
666  int i;
667  int res = 0;
668 
669  Assert(LWLockHeldByMe(LogicalRepWorkerLock));
670 
671  /* Search for attached worker for a given subscription id. */
672  for (i = 0; i < max_logical_replication_workers; i++)
673  {
675 
676  if (w->subid == subid && OidIsValid(w->relid))
677  res++;
678  }
679 
680  return res;
681 }
#define OidIsValid(objectId)
Definition: c.h:711
int i
Definition: isn.c:73
bool LWLockHeldByMe(LWLock *lock)
Definition: lwlock.c:1918

References Assert(), i, LogicalRepCtx, LWLockHeldByMe(), max_logical_replication_workers, OidIsValid, LogicalRepWorker::relid, res, LogicalRepWorker::subid, and LogicalRepCtxStruct::workers.

Referenced by logicalrep_worker_launch(), and process_syncing_tables_for_apply().

◆ logicalrep_worker_attach()

void logicalrep_worker_attach ( int  slot)

Definition at line 565 of file launcher.c.

566 {
567  /* Block concurrent access. */
568  LWLockAcquire(LogicalRepWorkerLock, LW_EXCLUSIVE);
569 
570  Assert(slot >= 0 && slot < max_logical_replication_workers);
572 
574  {
575  LWLockRelease(LogicalRepWorkerLock);
576  ereport(ERROR,
577  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
578  errmsg("logical replication worker slot %d is empty, cannot attach",
579  slot)));
580  }
581 
583  {
584  LWLockRelease(LogicalRepWorkerLock);
585  ereport(ERROR,
586  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
587  errmsg("logical replication worker slot %d is already used by "
588  "another worker, cannot attach", slot)));
589  }
590 
593 
594  LWLockRelease(LogicalRepWorkerLock);
595 }
int errcode(int sqlerrcode)
Definition: elog.c:695
int errmsg(const char *fmt,...)
Definition: elog.c:906
#define ERROR
Definition: elog.h:35
LogicalRepWorker * MyLogicalRepWorker
Definition: launcher.c:59
static void logicalrep_worker_onexit(int code, Datum arg)
Definition: launcher.c:644
@ LW_EXCLUSIVE
Definition: lwlock.h:112
PGPROC * MyProc
Definition: proc.c:68

References Assert(), before_shmem_exit(), ereport, errcode(), errmsg(), ERROR, LogicalRepWorker::in_use, logicalrep_worker_onexit(), LogicalRepCtx, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), max_logical_replication_workers, MyLogicalRepWorker, MyProc, LogicalRepWorker::proc, and LogicalRepCtxStruct::workers.

Referenced by ApplyWorkerMain().

◆ logicalrep_worker_cleanup()

static void logicalrep_worker_cleanup ( LogicalRepWorker worker)
static

Definition at line 615 of file launcher.c.

616 {
617  Assert(LWLockHeldByMeInMode(LogicalRepWorkerLock, LW_EXCLUSIVE));
618 
619  worker->in_use = false;
620  worker->proc = NULL;
621  worker->dbid = InvalidOid;
622  worker->userid = InvalidOid;
623  worker->subid = InvalidOid;
624  worker->relid = InvalidOid;
625 }
bool LWLockHeldByMeInMode(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1962

References Assert(), LogicalRepWorker::dbid, LogicalRepWorker::in_use, InvalidOid, LW_EXCLUSIVE, LWLockHeldByMeInMode(), LogicalRepWorker::proc, LogicalRepWorker::relid, LogicalRepWorker::subid, and LogicalRepWorker::userid.

Referenced by logicalrep_worker_detach(), logicalrep_worker_launch(), and WaitForReplicationWorkerAttach().

◆ logicalrep_worker_detach()

static void logicalrep_worker_detach ( void  )
static

Definition at line 601 of file launcher.c.

602 {
603  /* Block concurrent access. */
604  LWLockAcquire(LogicalRepWorkerLock, LW_EXCLUSIVE);
605 
607 
608  LWLockRelease(LogicalRepWorkerLock);
609 }
static void logicalrep_worker_cleanup(LogicalRepWorker *worker)
Definition: launcher.c:615

References logicalrep_worker_cleanup(), LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), and MyLogicalRepWorker.

Referenced by logicalrep_worker_onexit().

◆ logicalrep_worker_find()

LogicalRepWorker* logicalrep_worker_find ( Oid  subid,
Oid  relid,
bool  only_running 
)

Definition at line 215 of file launcher.c.

216 {
217  int i;
218  LogicalRepWorker *res = NULL;
219 
220  Assert(LWLockHeldByMe(LogicalRepWorkerLock));
221 
222  /* Search for attached worker for a given subscription id. */
223  for (i = 0; i < max_logical_replication_workers; i++)
224  {
226 
227  if (w->in_use && w->subid == subid && w->relid == relid &&
228  (!only_running || w->proc))
229  {
230  res = w;
231  break;
232  }
233  }
234 
235  return res;
236 }

References Assert(), i, LogicalRepWorker::in_use, LogicalRepCtx, LWLockHeldByMe(), max_logical_replication_workers, LogicalRepWorker::proc, LogicalRepWorker::relid, res, LogicalRepWorker::subid, and LogicalRepCtxStruct::workers.

Referenced by ApplyLauncherMain(), logicalrep_worker_stop(), logicalrep_worker_wakeup(), process_syncing_tables_for_apply(), wait_for_relation_state_change(), and wait_for_worker_state_change().

◆ logicalrep_worker_launch()

void logicalrep_worker_launch ( Oid  dbid,
Oid  subid,
const char *  subname,
Oid  userid,
Oid  relid 
)

Definition at line 266 of file launcher.c.

268 {
269  BackgroundWorker bgw;
270  BackgroundWorkerHandle *bgw_handle;
271  uint16 generation;
272  int i;
273  int slot = 0;
274  LogicalRepWorker *worker = NULL;
275  int nsyncworkers;
277 
278  ereport(DEBUG1,
279  (errmsg_internal("starting logical replication worker for subscription \"%s\"",
280  subname)));
281 
282  /* Report this after the initial starting message for consistency. */
283  if (max_replication_slots == 0)
284  ereport(ERROR,
285  (errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
286  errmsg("cannot start logical replication workers when max_replication_slots = 0")));
287 
288  /*
289  * We need to do the modification of the shared memory under lock so that
290  * we have consistent view.
291  */
292  LWLockAcquire(LogicalRepWorkerLock, LW_EXCLUSIVE);
293 
294 retry:
295  /* Find unused worker slot. */
296  for (i = 0; i < max_logical_replication_workers; i++)
297  {
299 
300  if (!w->in_use)
301  {
302  worker = w;
303  slot = i;
304  break;
305  }
306  }
307 
308  nsyncworkers = logicalrep_sync_worker_count(subid);
309 
311 
312  /*
313  * If we didn't find a free slot, try to do garbage collection. The
314  * reason we do this is because if some worker failed to start up and its
315  * parent has crashed while waiting, the in_use state was never cleared.
316  */
317  if (worker == NULL || nsyncworkers >= max_sync_workers_per_subscription)
318  {
319  bool did_cleanup = false;
320 
321  for (i = 0; i < max_logical_replication_workers; i++)
322  {
324 
325  /*
326  * If the worker was marked in use but didn't manage to attach in
327  * time, clean it up.
328  */
329  if (w->in_use && !w->proc &&
332  {
333  elog(WARNING,
334  "logical replication worker for subscription %u took too long to start; canceled",
335  w->subid);
336 
338  did_cleanup = true;
339  }
340  }
341 
342  if (did_cleanup)
343  goto retry;
344  }
345 
346  /*
347  * We don't allow to invoke more sync workers once we have reached the
348  * sync worker limit per subscription. So, just return silently as we
349  * might get here because of an otherwise harmless race condition.
350  */
351  if (OidIsValid(relid) && nsyncworkers >= max_sync_workers_per_subscription)
352  {
353  LWLockRelease(LogicalRepWorkerLock);
354  return;
355  }
356 
357  /*
358  * However if there are no more free worker slots, inform user about it
359  * before exiting.
360  */
361  if (worker == NULL)
362  {
363  LWLockRelease(LogicalRepWorkerLock);
365  (errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
366  errmsg("out of logical replication worker slots"),
367  errhint("You might need to increase max_logical_replication_workers.")));
368  return;
369  }
370 
371  /* Prepare the worker slot. */
372  worker->launch_time = now;
373  worker->in_use = true;
374  worker->generation++;
375  worker->proc = NULL;
376  worker->dbid = dbid;
377  worker->userid = userid;
378  worker->subid = subid;
379  worker->relid = relid;
380  worker->relstate = SUBREL_STATE_UNKNOWN;
382  worker->stream_fileset = NULL;
383  worker->last_lsn = InvalidXLogRecPtr;
386  worker->reply_lsn = InvalidXLogRecPtr;
387  TIMESTAMP_NOBEGIN(worker->reply_time);
388 
389  /* Before releasing lock, remember generation for future identification. */
390  generation = worker->generation;
391 
392  LWLockRelease(LogicalRepWorkerLock);
393 
394  /* Register the new dynamic worker. */
395  memset(&bgw, 0, sizeof(bgw));
399  snprintf(bgw.bgw_library_name, BGW_MAXLEN, "postgres");
400  snprintf(bgw.bgw_function_name, BGW_MAXLEN, "ApplyWorkerMain");
401  if (OidIsValid(relid))
403  "logical replication worker for subscription %u sync %u", subid, relid);
404  else
406  "logical replication worker for subscription %u", subid);
407  snprintf(bgw.bgw_type, BGW_MAXLEN, "logical replication worker");
408 
411  bgw.bgw_main_arg = Int32GetDatum(slot);
412 
413  if (!RegisterDynamicBackgroundWorker(&bgw, &bgw_handle))
414  {
415  /* Failed to start worker, so clean up the worker slot. */
416  LWLockAcquire(LogicalRepWorkerLock, LW_EXCLUSIVE);
417  Assert(generation == worker->generation);
419  LWLockRelease(LogicalRepWorkerLock);
420 
422  (errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
423  errmsg("out of background worker slots"),
424  errhint("You might need to increase max_worker_processes.")));
425  return;
426  }
427 
428  /* Now wait until it attaches. */
429  WaitForReplicationWorkerAttach(worker, generation, bgw_handle);
430 }
bool RegisterDynamicBackgroundWorker(BackgroundWorker *worker, BackgroundWorkerHandle **handle)
Definition: bgworker.c:956
#define BGW_NEVER_RESTART
Definition: bgworker.h:85
unsigned short uint16
Definition: c.h:441
#define TIMESTAMP_NOBEGIN(j)
Definition: timestamp.h:151
int errhint(const char *fmt,...)
Definition: elog.c:1153
#define WARNING
Definition: elog.h:32
static void WaitForReplicationWorkerAttach(LogicalRepWorker *worker, uint16 generation, BackgroundWorkerHandle *handle)
Definition: launcher.c:157
int max_sync_workers_per_subscription
Definition: launcher.c:57
int logicalrep_sync_worker_count(Oid subid)
Definition: launcher.c:664
NameData subname
static Datum Int32GetDatum(int32 X)
Definition: postgres.h:560
int max_replication_slots
Definition: slot.c:101
XLogRecPtr relstate_lsn
TimestampTz last_recv_time
TimestampTz launch_time
TimestampTz reply_time
FileSet * stream_fileset
XLogRecPtr reply_lsn
XLogRecPtr last_lsn
TimestampTz last_send_time
int wal_receiver_timeout
Definition: walreceiver.c:91
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28

References Assert(), BackgroundWorker::bgw_flags, BackgroundWorker::bgw_function_name, BackgroundWorker::bgw_library_name, BackgroundWorker::bgw_main_arg, BGW_MAXLEN, BackgroundWorker::bgw_name, BGW_NEVER_RESTART, BackgroundWorker::bgw_notify_pid, BackgroundWorker::bgw_restart_time, BackgroundWorker::bgw_start_time, BackgroundWorker::bgw_type, BGWORKER_BACKEND_DATABASE_CONNECTION, BGWORKER_SHMEM_ACCESS, BgWorkerStart_RecoveryFinished, LogicalRepWorker::dbid, DEBUG1, elog(), ereport, errcode(), errhint(), errmsg(), errmsg_internal(), ERROR, LogicalRepWorker::generation, GetCurrentTimestamp(), i, LogicalRepWorker::in_use, Int32GetDatum(), InvalidXLogRecPtr, LogicalRepWorker::last_lsn, LogicalRepWorker::last_recv_time, LogicalRepWorker::last_send_time, LogicalRepWorker::launch_time, logicalrep_sync_worker_count(), logicalrep_worker_cleanup(), LogicalRepCtx, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), max_logical_replication_workers, max_replication_slots, max_sync_workers_per_subscription, MyProcPid, now(), OidIsValid, LogicalRepWorker::proc, RegisterDynamicBackgroundWorker(), LogicalRepWorker::relid, LogicalRepWorker::relstate, LogicalRepWorker::relstate_lsn, LogicalRepWorker::reply_lsn, LogicalRepWorker::reply_time, snprintf, LogicalRepWorker::stream_fileset, LogicalRepWorker::subid, subname, TIMESTAMP_NOBEGIN, TimestampDifferenceExceeds(), LogicalRepWorker::userid, WaitForReplicationWorkerAttach(), wal_receiver_timeout, WARNING, and LogicalRepCtxStruct::workers.

Referenced by ApplyLauncherMain(), and process_syncing_tables_for_apply().

◆ logicalrep_worker_onexit()

static void logicalrep_worker_onexit ( int  code,
Datum  arg 
)
static

Definition at line 644 of file launcher.c.

645 {
646  /* Disconnect gracefully from the remote side. */
649 
651 
652  /* Cleanup fileset used for streaming transactions. */
653  if (MyLogicalRepWorker->stream_fileset != NULL)
655 
657 }
WalReceiverConn * LogRepWorkerWalRcvConn
Definition: worker.c:251
void FileSetDeleteAll(FileSet *fileset)
Definition: fileset.c:152
static void logicalrep_worker_detach(void)
Definition: launcher.c:601
#define walrcv_disconnect(conn)
Definition: walreceiver.h:436

References ApplyLauncherWakeup(), FileSetDeleteAll(), logicalrep_worker_detach(), LogRepWorkerWalRcvConn, MyLogicalRepWorker, LogicalRepWorker::stream_fileset, and walrcv_disconnect.

Referenced by logicalrep_worker_attach().

◆ logicalrep_worker_stop()

void logicalrep_worker_stop ( Oid  subid,
Oid  relid 
)

Definition at line 437 of file launcher.c.

438 {
439  LogicalRepWorker *worker;
440  uint16 generation;
441 
442  LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
443 
444  worker = logicalrep_worker_find(subid, relid, false);
445 
446  /* No worker, nothing to do. */
447  if (!worker)
448  {
449  LWLockRelease(LogicalRepWorkerLock);
450  return;
451  }
452 
453  /*
454  * Remember which generation was our worker so we can check if what we see
455  * is still the same one.
456  */
457  generation = worker->generation;
458 
459  /*
460  * If we found a worker but it does not have proc set then it is still
461  * starting up; wait for it to finish starting and then kill it.
462  */
463  while (worker->in_use && !worker->proc)
464  {
465  int rc;
466 
467  LWLockRelease(LogicalRepWorkerLock);
468 
469  /* Wait a bit --- we don't expect to have to wait long. */
470  rc = WaitLatch(MyLatch,
473 
474  if (rc & WL_LATCH_SET)
475  {
478  }
479 
480  /* Recheck worker status. */
481  LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
482 
483  /*
484  * Check whether the worker slot is no longer used, which would mean
485  * that the worker has exited, or whether the worker generation is
486  * different, meaning that a different worker has taken the slot.
487  */
488  if (!worker->in_use || worker->generation != generation)
489  {
490  LWLockRelease(LogicalRepWorkerLock);
491  return;
492  }
493 
494  /* Worker has assigned proc, so it has started. */
495  if (worker->proc)
496  break;
497  }
498 
499  /* Now terminate the worker ... */
500  kill(worker->proc->pid, SIGTERM);
501 
502  /* ... and wait for it to die. */
503  for (;;)
504  {
505  int rc;
506 
507  /* is it gone? */
508  if (!worker->proc || worker->generation != generation)
509  break;
510 
511  LWLockRelease(LogicalRepWorkerLock);
512 
513  /* Wait a bit --- we don't expect to have to wait long. */
514  rc = WaitLatch(MyLatch,
517 
518  if (rc & WL_LATCH_SET)
519  {
522  }
523 
524  LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
525  }
526 
527  LWLockRelease(LogicalRepWorkerLock);
528 }
int pid
Definition: proc.h:186
@ WAIT_EVENT_BGWORKER_STARTUP
Definition: wait_event.h:87
@ WAIT_EVENT_BGWORKER_SHUTDOWN
Definition: wait_event.h:86

References CHECK_FOR_INTERRUPTS, LogicalRepWorker::generation, LogicalRepWorker::in_use, kill, logicalrep_worker_find(), LW_SHARED, LWLockAcquire(), LWLockRelease(), MyLatch, PGPROC::pid, LogicalRepWorker::proc, ResetLatch(), WAIT_EVENT_BGWORKER_SHUTDOWN, WAIT_EVENT_BGWORKER_STARTUP, WaitLatch(), WL_EXIT_ON_PM_DEATH, WL_LATCH_SET, and WL_TIMEOUT.

Referenced by AlterSubscription_refresh(), and DropSubscription().

◆ logicalrep_worker_wakeup()

void logicalrep_worker_wakeup ( Oid  subid,
Oid  relid 
)

Definition at line 534 of file launcher.c.

535 {
536  LogicalRepWorker *worker;
537 
538  LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
539 
540  worker = logicalrep_worker_find(subid, relid, true);
541 
542  if (worker)
544 
545  LWLockRelease(LogicalRepWorkerLock);
546 }
void logicalrep_worker_wakeup_ptr(LogicalRepWorker *worker)
Definition: launcher.c:554

References logicalrep_worker_find(), logicalrep_worker_wakeup_ptr(), LW_SHARED, LWLockAcquire(), and LWLockRelease().

Referenced by pg_attribute_noreturn().

◆ logicalrep_worker_wakeup_ptr()

void logicalrep_worker_wakeup_ptr ( LogicalRepWorker worker)

Definition at line 554 of file launcher.c.

555 {
556  Assert(LWLockHeldByMe(LogicalRepWorkerLock));
557 
558  SetLatch(&worker->proc->procLatch);
559 }
void SetLatch(Latch *latch)
Definition: latch.c:591
Latch procLatch
Definition: proc.h:170

References Assert(), LWLockHeldByMe(), LogicalRepWorker::proc, PGPROC::procLatch, and SetLatch().

Referenced by logicalrep_worker_wakeup(), process_syncing_tables_for_apply(), and wait_for_worker_state_change().

◆ logicalrep_workers_find()

List* logicalrep_workers_find ( Oid  subid,
bool  only_running 
)

Definition at line 243 of file launcher.c.

244 {
245  int i;
246  List *res = NIL;
247 
248  Assert(LWLockHeldByMe(LogicalRepWorkerLock));
249 
250  /* Search for attached worker for a given subscription id. */
251  for (i = 0; i < max_logical_replication_workers; i++)
252  {
254 
255  if (w->in_use && w->subid == subid && (!only_running || w->proc))
256  res = lappend(res, w);
257  }
258 
259  return res;
260 }

References Assert(), i, LogicalRepWorker::in_use, lappend(), LogicalRepCtx, LWLockHeldByMe(), max_logical_replication_workers, NIL, LogicalRepWorker::proc, res, LogicalRepWorker::subid, and LogicalRepCtxStruct::workers.

Referenced by DropSubscription().

◆ pg_stat_get_subscription()

Datum pg_stat_get_subscription ( PG_FUNCTION_ARGS  )

Definition at line 927 of file launcher.c.

928 {
929 #define PG_STAT_GET_SUBSCRIPTION_COLS 8
930  Oid subid = PG_ARGISNULL(0) ? InvalidOid : PG_GETARG_OID(0);
931  int i;
932  ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
933 
934  InitMaterializedSRF(fcinfo, 0);
935 
936  /* Make sure we get consistent view of the workers. */
937  LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
938 
939  for (i = 0; i < max_logical_replication_workers; i++)
940  {
941  /* for each row */
943  bool nulls[PG_STAT_GET_SUBSCRIPTION_COLS] = {0};
944  int worker_pid;
945  LogicalRepWorker worker;
946 
947  memcpy(&worker, &LogicalRepCtx->workers[i],
948  sizeof(LogicalRepWorker));
949  if (!worker.proc || !IsBackendPid(worker.proc->pid))
950  continue;
951 
952  if (OidIsValid(subid) && worker.subid != subid)
953  continue;
954 
955  worker_pid = worker.proc->pid;
956 
957  values[0] = ObjectIdGetDatum(worker.subid);
958  if (OidIsValid(worker.relid))
959  values[1] = ObjectIdGetDatum(worker.relid);
960  else
961  nulls[1] = true;
962  values[2] = Int32GetDatum(worker_pid);
963  if (XLogRecPtrIsInvalid(worker.last_lsn))
964  nulls[3] = true;
965  else
966  values[3] = LSNGetDatum(worker.last_lsn);
967  if (worker.last_send_time == 0)
968  nulls[4] = true;
969  else
971  if (worker.last_recv_time == 0)
972  nulls[5] = true;
973  else
975  if (XLogRecPtrIsInvalid(worker.reply_lsn))
976  nulls[6] = true;
977  else
978  values[6] = LSNGetDatum(worker.reply_lsn);
979  if (worker.reply_time == 0)
980  nulls[7] = true;
981  else
983 
984  tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc,
985  values, nulls);
986 
987  /*
988  * If only a single subscription was requested, and we found it,
989  * break.
990  */
991  if (OidIsValid(subid))
992  break;
993  }
994 
995  LWLockRelease(LogicalRepWorkerLock);
996 
997  return (Datum) 0;
998 }
static Datum values[MAXATTR]
Definition: bootstrap.c:156
#define PG_GETARG_OID(n)
Definition: fmgr.h:275
#define PG_ARGISNULL(n)
Definition: fmgr.h:209
void InitMaterializedSRF(FunctionCallInfo fcinfo, bits32 flags)
Definition: funcapi.c:76
#define PG_STAT_GET_SUBSCRIPTION_COLS
static Datum LSNGetDatum(XLogRecPtr X)
Definition: pg_lsn.h:28
static Datum ObjectIdGetDatum(Oid X)
Definition: postgres.h:600
unsigned int Oid
Definition: postgres_ext.h:31
bool IsBackendPid(int pid)
Definition: procarray.c:3257
TupleDesc setDesc
Definition: execnodes.h:332
Tuplestorestate * setResult
Definition: execnodes.h:331
void tuplestore_putvalues(Tuplestorestate *state, TupleDesc tdesc, Datum *values, bool *isnull)
Definition: tuplestore.c:750
static Datum TimestampTzGetDatum(TimestampTz X)
Definition: timestamp.h:52
#define XLogRecPtrIsInvalid(r)
Definition: xlogdefs.h:29

References i, InitMaterializedSRF(), Int32GetDatum(), InvalidOid, IsBackendPid(), LogicalRepWorker::last_lsn, LogicalRepWorker::last_recv_time, LogicalRepWorker::last_send_time, LogicalRepCtx, LSNGetDatum(), LW_SHARED, LWLockAcquire(), LWLockRelease(), max_logical_replication_workers, ObjectIdGetDatum(), OidIsValid, PG_ARGISNULL, PG_GETARG_OID, PG_STAT_GET_SUBSCRIPTION_COLS, PGPROC::pid, LogicalRepWorker::proc, LogicalRepWorker::relid, LogicalRepWorker::reply_lsn, LogicalRepWorker::reply_time, ReturnSetInfo::setDesc, ReturnSetInfo::setResult, LogicalRepWorker::subid, TimestampTzGetDatum(), tuplestore_putvalues(), values, LogicalRepCtxStruct::workers, and XLogRecPtrIsInvalid.

◆ WaitForReplicationWorkerAttach()

static void WaitForReplicationWorkerAttach ( LogicalRepWorker worker,
uint16  generation,
BackgroundWorkerHandle handle 
)
static

Definition at line 157 of file launcher.c.

160 {
162  int rc;
163 
164  for (;;)
165  {
166  pid_t pid;
167 
169 
170  LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
171 
172  /* Worker either died or has started; no need to do anything. */
173  if (!worker->in_use || worker->proc)
174  {
175  LWLockRelease(LogicalRepWorkerLock);
176  return;
177  }
178 
179  LWLockRelease(LogicalRepWorkerLock);
180 
181  /* Check if worker has died before attaching, and clean up after it. */
182  status = GetBackgroundWorkerPid(handle, &pid);
183 
184  if (status == BGWH_STOPPED)
185  {
186  LWLockAcquire(LogicalRepWorkerLock, LW_EXCLUSIVE);
187  /* Ensure that this was indeed the worker we waited for. */
188  if (generation == worker->generation)
190  LWLockRelease(LogicalRepWorkerLock);
191  return;
192  }
193 
194  /*
195  * We need timeout because we generally don't get notified via latch
196  * about the worker attach. But we don't expect to have to wait long.
197  */
198  rc = WaitLatch(MyLatch,
201 
202  if (rc & WL_LATCH_SET)
203  {
206  }
207  }
208 }
BgwHandleStatus GetBackgroundWorkerPid(BackgroundWorkerHandle *handle, pid_t *pidp)
Definition: bgworker.c:1068
BgwHandleStatus
Definition: bgworker.h:104
@ BGWH_STOPPED
Definition: bgworker.h:107
static void static void status(const char *fmt,...) pg_attribute_printf(1
Definition: pg_regress.c:225

References BGWH_STOPPED, CHECK_FOR_INTERRUPTS, LogicalRepWorker::generation, GetBackgroundWorkerPid(), LogicalRepWorker::in_use, logicalrep_worker_cleanup(), LW_EXCLUSIVE, LW_SHARED, LWLockAcquire(), LWLockRelease(), MyLatch, LogicalRepWorker::proc, ResetLatch(), status(), WAIT_EVENT_BGWORKER_STARTUP, WaitLatch(), WL_EXIT_ON_PM_DEATH, WL_LATCH_SET, and WL_TIMEOUT.

Referenced by logicalrep_worker_launch().

Variable Documentation

◆ LogicalRepCtx

◆ max_logical_replication_workers

◆ max_sync_workers_per_subscription

int max_sync_workers_per_subscription = 2

Definition at line 57 of file launcher.c.

Referenced by logicalrep_worker_launch(), and process_syncing_tables_for_apply().

◆ MyLogicalRepWorker

◆ on_commit_launcher_wakeup

bool on_commit_launcher_wakeup = false
static

Definition at line 78 of file launcher.c.

Referenced by ApplyLauncherWakeupAtCommit(), and AtEOXact_ApplyLauncher().