Flow completed

src/backend/distributed/operations/shard_split.c

@@ -1120,6 +1120,10 @@ NonBlockingShardSplit(SplitOperation splitOperation,
 					  List *shardSplitPointsList,
 					  List *workersForPlacementList)
 {
+	char *superUser = CitusExtensionOwnerName();
+	char *databaseName = get_database_name(MyDatabaseId);
+	int connectionFlags = FORCE_NEW_CONNECTION;
+
 	List *sourceColocatedShardIntervalList = ColocatedShardIntervalList(
 		shardIntervalToSplit);
 
@@ -1136,6 +1140,24 @@ NonBlockingShardSplit(SplitOperation splitOperation,
 	WorkerNode *sourceShardToCopyNode = FindNodeWithNodeId(sourceShardPlacement->nodeId,
 														   false /* missingOk */);
 
+	HTAB *shardSplitHashMapForPublication = CreateShardSplitInfoMapForPublication(
+		sourceColocatedShardIntervalList,
+		shardGroupSplitIntervalListList,
+		workersForPlacementList);
+
+	DropAllShardSplitLeftOvers(sourceShardToCopyNode, shardSplitHashMapForPublication);
+
+	MultiConnection *sourceConnection = GetNodeUserDatabaseConnection(connectionFlags,
+																	  sourceShardToCopyNode
+																	  ->
+																	  workerName,
+																	  sourceShardToCopyNode
+																	  ->
+																	  workerPort,
+																	  superUser,
+																	  databaseName);
+	ClaimConnectionExclusively(sourceConnection);
+
 	PG_TRY();
 	{
 		/*
@@ -1149,11 +1171,6 @@ NonBlockingShardSplit(SplitOperation splitOperation,
 			shardGroupSplitIntervalListList,
 			workersForPlacementList);
 
-		/* char *templateSnapShotName = CreateTemplateReplicationSlotAndReturnSnapshot( */
-		/*  shardIntervalToSplit, sourceShardToCopyNode); */
-
-		/* DoSplitCopy(sourceShardToCopyNode, sourceColocatedShardIntervalList, */
-		/*          shardGroupSplitIntervalListList, workersForPlacementList, NULL); */
 
 		CreateDummyShardsForShardGroup(
 			sourceColocatedShardIntervalList,
@@ -1161,12 +1178,58 @@ NonBlockingShardSplit(SplitOperation splitOperation,
 			sourceShardToCopyNode,
 			workersForPlacementList);
 
-		/*TODO: Refactor this method. BlockWrites is within this as of now, take it out */
-		SplitShardReplicationSetup(shardIntervalToSplit,
-								   sourceColocatedShardIntervalList,
-								   shardGroupSplitIntervalListList,
-								   sourceShardToCopyNode,
-								   workersForPlacementList);
+		CreateShardSplitPublications(sourceConnection, shardSplitHashMapForPublication);
+
+		/*Create Template Replication Slot */
+
+		/* DoSplitCopy */
+
+		/*worker_split_replication_setup_udf*/
+		List *replicationSlotInfoList = ExecuteSplitShardReplicationSetupUDF(
+			sourceShardToCopyNode,
+			sourceColocatedShardIntervalList,
+			shardGroupSplitIntervalListList,
+			workersForPlacementList);
+
+		/* Subscriber flow starts from here */
+		List *shardSplitSubscribersMetadataList =
+			PopulateShardSplitSubscriptionsMetadataList(
+				shardSplitHashMapForPublication, replicationSlotInfoList);
+
+		List *targetNodeConnectionList = CreateTargetNodeConnectionsForShardSplit(
+			shardSplitSubscribersMetadataList,
+			connectionFlags,
+			superUser, databaseName);
+
+		/* Create copies of template replication slot */
+		CreateReplicationSlots(sourceConnection, shardSplitSubscribersMetadataList);
+
+		CreateShardSplitSubscriptions(targetNodeConnectionList,
+									  shardSplitSubscribersMetadataList,
+									  sourceShardToCopyNode,
+									  superUser,
+									  databaseName);
+
+		WaitForShardSplitRelationSubscriptionsBecomeReady(
+			shardSplitSubscribersMetadataList);
+
+		XLogRecPtr sourcePosition = GetRemoteLogPosition(sourceConnection);
+		WaitForShardSplitRelationSubscriptionsToBeCaughtUp(sourcePosition,
+														   shardSplitSubscribersMetadataList);
+
+		CreateAuxiliaryStructuresForShardGroup(shardGroupSplitIntervalListList,
+											   workersForPlacementList);
+
+		sourcePosition = GetRemoteLogPosition(sourceConnection);
+		WaitForShardSplitRelationSubscriptionsToBeCaughtUp(sourcePosition,
+														   shardSplitSubscribersMetadataList);
+
+		BlockWritesToShardList(sourceColocatedShardIntervalList);
+
+		sourcePosition = GetRemoteLogPosition(sourceConnection);
+		WaitForShardSplitRelationSubscriptionsToBeCaughtUp(sourcePosition,
+														   shardSplitSubscribersMetadataList);
+
 		/*
 		 * Drop old shards and delete related metadata. Have to do that before
 		 * creating the new shard metadata, because there's cross-checks
@@ -1355,22 +1418,6 @@ SplitShardReplicationSetup(ShardInterval *shardIntervalToSplit,
 						   WorkerNode *sourceWorkerNode,
 						   List *destinationWorkerNodesList)
 {
-	/* / * // / *Create Template replication slot * / * / */
-	/* / * char *templateSnapShotName = CreateTemplateReplicationSlotAndReturnSnapshot( * / */
-	/* / *  shardIntervalToSplit, sourceWorkerNode); * / */
-	/* List *shardSplitPubSubMetadata = CreateShardSplitInfoMapForPublication( */
-	/*  sourceColocatedShardIntervalList, */
-	/*  shardGroupSplitIntervalListList, */
-	/*  destinationWorkerNodesList, */
-	/*  replicationSlotInfoList); */
-	/* earlier the above method used to take replication slot info as information */
-
-
-	/* LogicallyReplicateSplitShards(sourceWorkerNode, shardSplitPubSubMetadata, */
-	/*                            sourceColocatedShardIntervalList, */
-	/*                            shardGroupSplitIntervalListList, */
-	/*                            destinationWorkerNodesList); */
-
 	char *superUser = CitusExtensionOwnerName();
 	char *databaseName = get_database_name(MyDatabaseId);
 	int connectionFlags = FORCE_NEW_CONNECTION;
@@ -1424,7 +1471,7 @@ SplitShardReplicationSetup(ShardInterval *shardIntervalToSplit,
 	XLogRecPtr sourcePosition = GetRemoteLogPosition(sourceConnection);
 	WaitForShardSplitRelationSubscriptionsToBeCaughtUp(sourcePosition,
 													   shardSplitSubscribersMetadataList);
-	
+
 	CreateAuxiliaryStructuresForShardGroup(shardGroupSplitIntervalListList,
 										   destinationWorkerNodesList);
 

src/backend/distributed/replication/multi_logical_replication.c

@@ -2080,7 +2080,7 @@ GetSubscriptionPosition(MultiConnection *connection, Bitmapset *tableOwnerIds,
 void
 CreateShardSubscription(MultiConnection *connection, char *sourceNodeName,
 						int sourceNodePort, char *userName, char *databaseName,
-						char *publicationName,
+						char *publicationName, char *slotName,
 						Oid ownerId)
 {
 	StringInfo createSubscriptionCommand = makeStringInfo();
@@ -2107,11 +2107,12 @@ CreateShardSubscription(MultiConnection *connection, char *sourceNodeName,
 
 	appendStringInfo(createSubscriptionCommand,
 					 "CREATE SUBSCRIPTION %s CONNECTION %s PUBLICATION %s "
-					 "WITH (citus_use_authinfo=true, enabled=false)",
+					 "WITH (citus_use_authinfo=true, enabled=false, create_slot=false, copy_data=false, slot_name='%s')",
 					 quote_identifier(ShardSubscriptionName(ownerId,
 															SHARD_SPLIT_SUBSCRIPTION_PREFIX)),
 					 quote_literal_cstr(conninfo->data),
-					 quote_identifier(publicationName));
+					 quote_identifier(publicationName),
+					 slotName);
 
 	ExecuteCriticalRemoteCommand(connection, createSubscriptionCommand->data);
 	pfree(createSubscriptionCommand->data);

src/backend/distributed/shardsplit/shardsplit_logical_replication.c

@@ -32,6 +32,7 @@ ShardSplitSubscriberMetadata * CreateShardSplitSubscriberMetadata(Oid tableOwner
 																  nodeId,
 																  List *
 																  replicationSlotInfoList);
+
 static void CreateShardSplitPublicationForNode(MultiConnection *connection,
 											   List *shardList,
 											   uint32_t publicationForTargetNodeId, Oid
@@ -149,30 +150,6 @@ AddPublishableShardEntryInMap(uint32 targetNodeId, ShardInterval *shardInterval,
 }
 
 
-ShardSplitSubscriberMetadata *
-CreateShardSplitSubscriberMetadata(Oid tableOwnerId, uint32 nodeId,
-								   List *replicationSlotInfoList)
-{
-	ShardSplitSubscriberMetadata *shardSplitSubscriberMetadata = palloc0(
-		sizeof(ShardSplitSubscriberMetadata));
-	shardSplitSubscriberMetadata->tableOwnerId = tableOwnerId;
-
-	char *tableOwnerName = GetUserNameFromId(tableOwnerId, false);
-	ReplicationSlotInfo *replicationSlotInfo = NULL;
-	foreach_ptr(replicationSlotInfo, replicationSlotInfoList)
-	{
-		if (nodeId == replicationSlotInfo->targetNodeId &&
-			strcmp(tableOwnerName, replicationSlotInfo->tableOwnerName) == 0)
-		{
-			shardSplitSubscriberMetadata->slotInfo = replicationSlotInfo;
-			break;
-		}
-	}
-
-	return shardSplitSubscriberMetadata;
-}
-
-
 void
 LogicallyReplicateSplitShards(WorkerNode *sourceWorkerNode,
 							  List *shardSplitPubSubMetadataList,
@@ -281,6 +258,7 @@ CreateShardSplitSubscriptions(List *targetNodeConnectionList,
 								superUser,
 								databaseName,
 								ShardSplitPublicationName(publicationForNodeId, ownerId),
+								shardSplitPubSubMetadata->slotInfo->slotName,
 								ownerId);
 	}
 }
@@ -576,9 +554,67 @@ PopulateShardSplitSubscriptionsMetadataList(HTAB *shardSplitInfoHashMap,
 
 		shardSplitSubscriptionMetadataList = lappend(shardSplitSubscriptionMetadataList,
 													 shardSplitSubscriberMetadata);
-
-		/*replicationSlotInfoList = lappend(replicationSlotInfoList, replicationSlotInfo); */
 	}
 
 	return shardSplitSubscriptionMetadataList;
 }
+
+
+ShardSplitSubscriberMetadata *
+CreateShardSplitSubscriberMetadata(Oid tableOwnerId, uint32 nodeId,
+								   List *replicationSlotInfoList)
+{
+	ShardSplitSubscriberMetadata *shardSplitSubscriberMetadata = palloc0(
+		sizeof(ShardSplitSubscriberMetadata));
+	shardSplitSubscriberMetadata->tableOwnerId = tableOwnerId;
+
+	char *tableOwnerName = GetUserNameFromId(tableOwnerId, false);
+	ReplicationSlotInfo *replicationSlotInfo = NULL;
+	foreach_ptr(replicationSlotInfo, replicationSlotInfoList)
+	{
+		if (nodeId == replicationSlotInfo->targetNodeId &&
+			strcmp(tableOwnerName, replicationSlotInfo->tableOwnerName) == 0)
+		{
+			shardSplitSubscriberMetadata->slotInfo = replicationSlotInfo;
+			break;
+		}
+	}
+
+	PrintShardSplitPubSubMetadata(shardSplitSubscriberMetadata);
+
+	return shardSplitSubscriberMetadata;
+}
+
+
+/*TODO(saawasek): Remove existing slots before creating newer ones */
+
+/* extern void CreateReplicationSlots(MultiConnection *sourceNodeConnection, List * shardSplitSubscriberMetadataList); */
+void
+CreateReplicationSlots(MultiConnection *sourceNodeConnection,
+					   List *shardSplitSubscriberMetadataList)
+{
+	ShardSplitSubscriberMetadata *subscriberMetadata = NULL;
+	foreach_ptr(subscriberMetadata, shardSplitSubscriberMetadataList)
+	{
+		char *slotName = subscriberMetadata->slotInfo->slotName;
+
+		StringInfo createReplicationSlotCommand = makeStringInfo();
+
+		/* TODO(niupre): Replace pgoutput with an appropriate name (to e introduced in by saawasek's PR) */
+		appendStringInfo(createReplicationSlotCommand,
+						 "SELECT * FROM  pg_create_logical_replication_slot('%s','citus', false)",
+						 slotName);
+
+		PGresult *result = NULL;
+		int response = ExecuteOptionalRemoteCommand(sourceNodeConnection,
+													createReplicationSlotCommand->data,
+													&result);
+		if (response != RESPONSE_OKAY || !IsResponseOK(result) || PQntuples(result) != 1)
+		{
+			ReportResultError(sourceNodeConnection, result, ERROR);
+		}
+
+		PQclear(result);
+		ForgetResults(sourceNodeConnection);
+	}
+}

src/include/distributed/multi_logical_replication.h

@@ -38,7 +38,7 @@ extern void DropShardUser(MultiConnection *connection, char *username);
 extern void CreateShardSubscription(MultiConnection *connection, char *sourceNodeName,
 									int sourceNodePort, char *userName,
 									char *databaseName,
-									char *publicationName,
+									char *publicationName, char *slotName,
 									Oid ownerId);
 
 extern void WaitForRelationSubscriptionsBecomeReady(MultiConnection *targetConnection,

src/include/distributed/shardsplit_logical_replication.h

@@ -89,6 +89,8 @@ List * CreateTargetNodeConnectionsForShardSplit(List *shardSplitSubscribersMetad
 												int
 												connectionFlags, char *user,
 												char *databaseName);
+extern void CreateReplicationSlots(MultiConnection *sourceNodeConnection,
+								   List *shardSplitSubscriberMetadataList);
 
 /*used for debuggin. Remove later*/
 extern void PrintShardSplitPubSubMetadata(

src/test/regress/sql/citus_sameer.sql

@@ -48,15 +48,19 @@ SELECT nodeid AS worker_2_node FROM pg_dist_node WHERE nodeport=:worker_2_port \
 SELECT citus_split_shard_by_split_points(
 	1,
 	ARRAY['0'],
-	ARRAY[:worker_2_node, :worker_2_node],
+	ARRAY[:worker_1_node, :worker_2_node],
 	'force_logical');
--- On worker2, we want child shard 2 and dummy shard 1  --
--- on worker1, we want child shard 3 and 1 and dummy shard 2  --
+
+INSERT INTO table_to_split values(100,'a');
+INSERT INTO table_to_split values(400, 'a');
+INSERT INTO table_to_split values(500, 'a');
 
 \c - - - :worker_2_port
 SET search_path TO citus_split_shard_by_split_points_negative;
 SELECT * FROM show_catalog;
 SELECT * FROM pg_subscription;
+SELECT slot_name FROM pg_replication_slots;
+SELECT * FROM table_to_split_101;
 
 \c - - - :worker_1_port
 SET search_path TO citus_split_shard_by_split_points_negative;
@@ -64,3 +68,4 @@ SELECT * FROM show_catalog;
 SELECT * FROM pg_publication;
 SELECT * FROM pg_subscription;
 SELECT slot_name FROM pg_replication_slots;
+SELECT * FROM table_to_split_100;