diff options
Diffstat (limited to 'src/backend/postmaster/postmaster.c')
| -rw-r--r-- | src/backend/postmaster/postmaster.c | 44 |
1 files changed, 36 insertions, 8 deletions
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 73bacd89bcc..fa5aeed31db 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -499,6 +499,7 @@ typedef struct bool redirection_done; bool IsBinaryUpgrade; int max_safe_fds; + int MaxBackends; #ifdef WIN32 HANDLE PostmasterHandle; HANDLE initial_signal_pipe; @@ -897,15 +898,14 @@ PostmasterMain(int argc, char *argv[]) process_shared_preload_libraries(); /* - * If loadable modules have added background workers, MaxBackends needs to - * be updated. Do so now by forcing a no-op update of max_connections. - * XXX This is a pretty ugly way to do it, but it doesn't seem worth - * introducing a new entry point in guc.c to do it in a cleaner fashion. + * Now that loadable modules have had their chance to register background + * workers, calculate MaxBackends. Add one for the autovacuum launcher. */ - if (GetNumShmemAttachedBgworkers() > 0) - SetConfigOption("max_connections", - GetConfigOption("max_connections", false, false), - PGC_POSTMASTER, PGC_S_OVERRIDE); + MaxBackends = MaxConnections + autovacuum_max_workers + 1 + + GetNumShmemAttachedBgworkers(); + /* internal error because the values were all checked previously */ + if (MaxBackends > MAX_BACKENDS) + elog(ERROR, "too many backends configured"); /* * Establish input sockets. @@ -5152,6 +5152,8 @@ RegisterBackgroundWorker(BackgroundWorker *worker) { RegisteredBgWorker *rw; int namelen = strlen(worker->bgw_name); + static int maxworkers; + static int numworkers = 0; #ifdef EXEC_BACKEND @@ -5162,6 +5164,11 @@ RegisterBackgroundWorker(BackgroundWorker *worker) static int BackgroundWorkerCookie = 1; #endif + /* initialize upper limit on first call */ + if (numworkers == 0) + maxworkers = MAX_BACKENDS - + (MaxConnections + autovacuum_max_workers + 1); + if (!IsUnderPostmaster) ereport(LOG, (errmsg("registering background worker: %s", worker->bgw_name))); @@ -5215,6 +5222,23 @@ RegisterBackgroundWorker(BackgroundWorker *worker) } /* + * Enforce maximum number of workers. Note this is overly restrictive: + * we could allow more non-shmem-connected workers, because these don't + * count towards the MAX_BACKENDS limit elsewhere. This doesn't really + * matter for practical purposes; several million processes would need to + * run on a single server. + */ + if (++numworkers > maxworkers) + { + ereport(LOG, + (errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED), + errmsg("too many background workers"), + errdetail("Up to %d background workers can be registered with the current settings.", + maxworkers))); + return; + } + + /* * Copy the registration data into the registered workers list. */ rw = malloc(sizeof(RegisteredBgWorker) + namelen + 1); @@ -5836,6 +5860,8 @@ save_backend_variables(BackendParameters *param, Port *port, param->IsBinaryUpgrade = IsBinaryUpgrade; param->max_safe_fds = max_safe_fds; + param->MaxBackends = MaxBackends; + #ifdef WIN32 param->PostmasterHandle = PostmasterHandle; if (!write_duplicated_handle(¶m->initial_signal_pipe, @@ -6061,6 +6087,8 @@ restore_backend_variables(BackendParameters *param, Port *port) IsBinaryUpgrade = param->IsBinaryUpgrade; max_safe_fds = param->max_safe_fds; + MaxBackends = param->MaxBackends; + #ifdef WIN32 PostmasterHandle = param->PostmasterHandle; pgwin32_initial_signal_pipe = param->initial_signal_pipe; |