Fix some bugs

src/backend/distributed/shared_library_init.c

@@ -481,6 +481,7 @@ _PG_init(void)
 #endif
 
 	InitializeMaintenanceDaemon();
+	InitializeMaintenanceDaemonForAdminDB();
 
 	/* initialize coordinated transaction management */
 	InitializeTransactionManagement();

src/backend/distributed/utils/maintenanced.c

@@ -134,54 +134,48 @@ static void WarnMaintenanceDaemonNotStarted(void);
 void
 InitializeMaintenanceDaemon(void)
 {
-	elog(LOG, "InitializeMaintenanceDaemon");
 	prev_shmem_startup_hook = shmem_startup_hook;
 	shmem_startup_hook = MaintenanceDaemonShmemInit;
 }
 
+
+/*
+ * InitializeMaintenanceDaemonForAdminDB is called in _PG_Init
+ * at which stage we are not in a transaction or have databaseOid
+ */
 void
 InitializeMaintenanceDaemonForAdminDB(void)
 {
-	elog(LOG, "InitializeMaintenanceDaemonForAdmin");
-	
 	BackgroundWorker worker;
-        BackgroundWorkerHandle *handle = NULL;
 
-        memset(&worker, 0, sizeof(worker));
+	memset(&worker, 0, sizeof(worker));
 
-        SafeSnprintf(worker.bgw_name, sizeof(worker.bgw_name),
+	SafeSnprintf(worker.bgw_name, sizeof(worker.bgw_name),
-                              "Citus Maintenance Daemon: %u/%u",
+				 "Citus Maintenance Daemon: %u/%u",
-                               0, 0);
+				 0, 0);
 
-        /* request ability to connect to target database */
+	/* request ability to connect to target database */
-        worker.bgw_flags = BGWORKER_SHMEM_ACCESS | BGWORKER_BACKEND_DATABASE_CONNECTION;
+	worker.bgw_flags = BGWORKER_SHMEM_ACCESS | BGWORKER_BACKEND_DATABASE_CONNECTION;
 
-        /*
+	/*
-         * No point in getting started before able to run query, but we do
+	 * No point in getting started before able to run query, but we do
-         * want to get started on Hot-Standby.
+	 * want to get started on Hot-Standby.
-         */
+	 */
-        worker.bgw_start_time = BgWorkerStart_ConsistentState;
+	worker.bgw_start_time = BgWorkerStart_ConsistentState;
 
-        /* Restart after a bit after errors, but don't bog the system. */
+	/* Restart after a bit after errors, but don't bog the system. */
-        worker.bgw_restart_time = 5;
+	worker.bgw_restart_time = 5;
-        strcpy_s(worker.bgw_library_name,
+	strcpy_s(worker.bgw_library_name,
-                                sizeof(worker.bgw_library_name), "citus");
+			 sizeof(worker.bgw_library_name), "citus");
-        strcpy_s(worker.bgw_function_name, sizeof(worker.bgw_library_name),
+	strcpy_s(worker.bgw_function_name, sizeof(worker.bgw_library_name),
-                                 "CitusMaintenanceDaemonMain");
+			 "CitusMaintenanceDaemonMain");
 
-        worker.bgw_main_arg = (Datum)0;
+	worker.bgw_main_arg = (Datum) 0;
-        worker.bgw_notify_pid = MyProcPid;
-
-        if (!RegisterDynamicBackgroundWorker(&worker, &handle)) {
-		elog(LOG, "RegisterDynamicBackgroundWorker failed for admin");
-	}
-
-	pid_t pid;
-        WaitForBackgroundWorkerStartup(handle, &pid);
-
-        pfree(handle);
 
+	RegisterBackgroundWorker(&worker);
 }
+
+
 /*
  * InitializeMaintenanceDaemonBackend, called at backend start and
  * configuration changes, is responsible for starting a per-database
@@ -190,7 +184,6 @@ InitializeMaintenanceDaemonForAdminDB(void)
 void
 InitializeMaintenanceDaemonBackend(void)
 {
-	elog(LOG, "InitializeMaintenanceDaemonBackend");
 	Oid extensionOwner = CitusExtensionOwner();
 	bool found;
 
@@ -322,7 +315,6 @@ WarnMaintenanceDaemonNotStarted(void)
 void
 CitusMaintenanceDaemonMain(Datum main_arg)
 {
-	elog(LOG, "CitusMaintenanceDaemonMain");
 	Oid databaseOid = DatumGetObjectId(main_arg);
 	TimestampTz nextStatsCollectionTime USED_WITH_LIBCURL_ONLY =
 		TimestampTzPlusMilliseconds(GetCurrentTimestamp(), 60 * 1000);
@@ -342,68 +334,64 @@ CitusMaintenanceDaemonMain(Datum main_arg)
 
 	if (databaseOid == 0)
 	{
-
 		/* TODO : Get the admin database name from GUC contro_db*/
-		char* databaseName = "postgres";
+		char *databaseName = "postgres";
 
 		BackgroundWorkerInitializeConnection(databaseName, NULL, 0);
 
-		// Now we have a valid MyDatabaseId.
+		/* Now we have a valid MyDatabaseId. */
-		// Insert the daemon instance to the hash table.
+		/* Insert the daemon instance to the hash table. */
- 	       bool found;
+		bool found;
 
-        	LWLockAcquire(&MaintenanceDaemonControl->lock, LW_EXCLUSIVE);
+		LWLockAcquire(&MaintenanceDaemonControl->lock, LW_EXCLUSIVE);
 
 		myDbData = (MaintenanceDaemonDBData *) hash_search(
-        	        MaintenanceDaemonDBHash,
+			MaintenanceDaemonDBHash,
-                	&MyDatabaseId,
+			&MyDatabaseId,
-	                HASH_ENTER_NULL,
+			HASH_ENTER_NULL,
-        	        &found);
+			&found);
 
-	        if (!myDbData)
+		if (!myDbData)
-	        {
+		{
-                	LWLockRelease(&MaintenanceDaemonControl->lock);
+			LWLockRelease(&MaintenanceDaemonControl->lock);
-	                return;
+			return;
-        	}
+		}
 
-	        if (!found)
+		if (!found)
-        	{
+		{
-	               	/* ensure the values in MaintenanceDaemonDBData are zero */
+			/* ensure the values in MaintenanceDaemonDBData are zero */
-	            memset(((char *) myDbData) + sizeof(Oid), 0,
+			memset(((char *) myDbData) + sizeof(Oid), 0,
-        	                   sizeof(MaintenanceDaemonDBData) - sizeof(Oid));
+				   sizeof(MaintenanceDaemonDBData) - sizeof(Oid));
-
+		}
-        	     myDbData->userOid = 0;
-                     myDbData->workerPid = 0;
-	             myDbData->triggerNodeMetadataSync = false;
-	        }
 
 		before_shmem_exit(MaintenanceDaemonShmemExit, ObjectIdGetDatum(MyDatabaseId));
 		databaseOid = MyDatabaseId;
+		myDbData->userOid = GetSessionUserId();
 	}
 	else
 	{
 		LWLockAcquire(&MaintenanceDaemonControl->lock, LW_EXCLUSIVE);
 
-	        myDbData = (MaintenanceDaemonDBData *)
+		myDbData = (MaintenanceDaemonDBData *)
-                                                                                hash_search(MaintenanceDaemonDBHash, &databaseOid,
+				   hash_search(MaintenanceDaemonDBHash, &databaseOid,
-                                                                                                        HASH_FIND, NULL);
+							   HASH_FIND, NULL);
-        	if (!myDbData || myDbData->workerPid != 0)
+		if (!myDbData || myDbData->workerPid != 0)
-        	{
+		{
-                /*
+			/*
-                 * When the database crashes, background workers are restarted, but
+			 * When the database crashes, background workers are restarted, but
-                 * the state in shared memory is lost. In that case, we exit and
+			 * the state in shared memory is lost. In that case, we exit and
-                 * wait for a session to call InitializeMaintenanceDaemonBackend
+			 * wait for a session to call InitializeMaintenanceDaemonBackend
-                 * to properly add it to the hash.
+			 * to properly add it to the hash.
-                 */
+			 */
-
-			 LWLockRelease(&MaintenanceDaemonControl->lock);
-                	proc_exit(0);
 
+			LWLockRelease(&MaintenanceDaemonControl->lock);
+			proc_exit(0);
 		}
 		before_shmem_exit(MaintenanceDaemonShmemExit, main_arg);
 
 		BackgroundWorkerInitializeConnectionByOid(databaseOid, myDbData->userOid, 0);
 	}
+
 	/*
 	 * We do metadata sync in a separate background worker. We need its
 	 * handle to be able to check its status.
@@ -945,7 +933,6 @@ MaintenanceDaemonShmemSize(void)
 void
 MaintenanceDaemonShmemInit(void)
 {
-	elog(LOG, "MaintenanceDaemonShmemInit");
 	bool alreadyInitialized = false;
 	HASHCTL hashInfo;
 
@@ -997,7 +984,6 @@ MaintenanceDaemonShmemInit(void)
 static void
 MaintenanceDaemonShmemExit(int code, Datum arg)
 {
-	elog(LOG, "MaintenanceDaemonShmemExit");
 	Oid databaseOid = DatumGetObjectId(arg);
 
 	LWLockAcquire(&MaintenanceDaemonControl->lock, LW_EXCLUSIVE);
@@ -1108,7 +1094,6 @@ LockCitusExtension(void)
 void
 StopMaintenanceDaemon(Oid databaseId)
 {
-	elog(LOG, "StopMaintenanceDaemon");
 	bool found = false;
 	pid_t workerPid = 0;
 
@@ -1140,7 +1125,6 @@ StopMaintenanceDaemon(Oid databaseId)
 void
 TriggerNodeMetadataSync(Oid databaseId)
 {
-	elog(LOG, "TriggerNodeMetadataSync");
 	bool found = false;
 
 	LWLockAcquire(&MaintenanceDaemonControl->lock, LW_EXCLUSIVE);
@@ -1168,7 +1152,6 @@ TriggerNodeMetadataSync(Oid databaseId)
 static bool
 MetadataSyncTriggeredCheckAndReset(MaintenanceDaemonDBData *dbData)
 {
-	elog(LOG, "MetadataSyncTriggeredCheckAndReset");
 	LWLockAcquire(&MaintenanceDaemonControl->lock, LW_EXCLUSIVE);
 
 	bool metadataSyncTriggered = dbData->triggerNodeMetadataSync;