diff --git a/doc/src/sgml/ref/create_database.sgml b/doc/src/sgml/ref/create_database.sgml index cf33746c1e2..cf0d53b3014 100644 --- a/doc/src/sgml/ref/create_database.sgml +++ b/doc/src/sgml/ref/create_database.sgml @@ -258,7 +258,8 @@ CREATE DATABASE name The CONNECTION LIMIT option is only enforced approximately; if two new sessions start at about the same time when just one connection slot remains for the database, it is possible that - both will fail. Also, the limit is not enforced against superusers. + both will fail. Also, the limit is not enforced against superusers or + background worker processes. diff --git a/doc/src/sgml/ref/create_role.sgml b/doc/src/sgml/ref/create_role.sgml index a3b8ed9ab4c..2ae576ede69 100644 --- a/doc/src/sgml/ref/create_role.sgml +++ b/doc/src/sgml/ref/create_role.sgml @@ -198,7 +198,10 @@ CREATE ROLE name [ [ WITH ] If role can log in, this specifies how many concurrent connections - the role can make. -1 (the default) means no limit. + the role can make. -1 (the default) means no limit. Note that only + normal connections are counted towards this limit. Neither prepared + transactions nor background worker connections are counted towards + this limit. diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c index 5415604993a..ea7bfa0578b 100644 --- a/src/backend/access/transam/twophase.c +++ b/src/backend/access/transam/twophase.c @@ -420,6 +420,7 @@ MarkAsPreparing(TransactionId xid, const char *gid, proc->backendId = InvalidBackendId; proc->databaseId = databaseid; proc->roleId = owner; + proc->isBackgroundWorker = false; proc->lwWaiting = false; proc->lwWaitMode = 0; proc->waitLock = NULL; diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c index 4adb286d5b5..651c561dfd5 100644 --- a/src/backend/storage/ipc/procarray.c +++ b/src/backend/storage/ipc/procarray.c @@ -2751,6 +2751,38 @@ CountDBBackends(Oid databaseid) return count; } +/* + * CountDBConnections --- counts database backends ignoring any background + * worker processes + */ +int +CountDBConnections(Oid databaseid) +{ + ProcArrayStruct *arrayP = procArray; + int count = 0; + int index; + + LWLockAcquire(ProcArrayLock, LW_SHARED); + + for (index = 0; index < arrayP->numProcs; index++) + { + int pgprocno = arrayP->pgprocnos[index]; + volatile PGPROC *proc = &allProcs[pgprocno]; + + if (proc->pid == 0) + continue; /* do not count prepared xacts */ + if (proc->isBackgroundWorker) + continue; /* do not count background workers */ + if (!OidIsValid(databaseid) || + proc->databaseId == databaseid) + count++; + } + + LWLockRelease(ProcArrayLock); + + return count; +} + /* * CancelDBBackends --- cancel backends that are using specified database */ @@ -2810,6 +2842,8 @@ CountUserBackends(Oid roleid) if (proc->pid == 0) continue; /* do not count prepared xacts */ + if (proc->isBackgroundWorker) + continue; /* do not count background workers */ if (proc->roleId == roleid) count++; } diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c index 9a758bd9160..cb6e1e3e5bc 100644 --- a/src/backend/storage/lmgr/proc.c +++ b/src/backend/storage/lmgr/proc.c @@ -372,6 +372,7 @@ InitProcess(void) MyProc->backendId = InvalidBackendId; MyProc->databaseId = InvalidOid; MyProc->roleId = InvalidOid; + MyProc->isBackgroundWorker = IsBackgroundWorker; MyPgXact->delayChkpt = false; MyPgXact->vacuumFlags = 0; /* NB -- autovac launcher intentionally does not set IS_AUTOVACUUM */ @@ -544,6 +545,7 @@ InitAuxiliaryProcess(void) MyProc->backendId = InvalidBackendId; MyProc->databaseId = InvalidOid; MyProc->roleId = InvalidOid; + MyProc->isBackgroundWorker = IsBackgroundWorker; MyPgXact->delayChkpt = false; MyPgXact->vacuumFlags = 0; MyProc->lwWaiting = false; diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c index 824d5abf11f..cde4a798b62 100644 --- a/src/backend/utils/init/postinit.c +++ b/src/backend/utils/init/postinit.c @@ -350,7 +350,7 @@ CheckMyDatabase(const char *name, bool am_superuser) */ if (dbform->datconnlimit >= 0 && !am_superuser && - CountDBBackends(MyDatabaseId) > dbform->datconnlimit) + CountDBConnections(MyDatabaseId) > dbform->datconnlimit) ereport(FATAL, (errcode(ERRCODE_TOO_MANY_CONNECTIONS), errmsg("too many connections for database \"%s\"", diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h index 775c66a1971..c44d82b90c0 100644 --- a/src/include/storage/proc.h +++ b/src/include/storage/proc.h @@ -102,6 +102,8 @@ struct PGPROC Oid databaseId; /* OID of database this backend is using */ Oid roleId; /* OID of role using this backend */ + bool isBackgroundWorker; /* true if background worker. */ + /* * While in hot standby mode, shows that a conflict signal has been sent * for the current transaction. Set/cleared while holding ProcArrayLock, diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h index dd37c0cb070..ecc3c4a4f63 100644 --- a/src/include/storage/procarray.h +++ b/src/include/storage/procarray.h @@ -73,6 +73,7 @@ extern pid_t CancelVirtualTransaction(VirtualTransactionId vxid, ProcSignalReaso extern bool MinimumActiveBackends(int min); extern int CountDBBackends(Oid databaseid); +extern int CountDBConnections(Oid databaseid); extern void CancelDBBackends(Oid databaseid, ProcSignalReason sigmode, bool conflictPending); extern int CountUserBackends(Oid roleid); extern bool CountOtherDBBackends(Oid databaseId,