Merge pull request #5734 from citusdata/remove_citus_backend

Drop support for CitusInitiatedBackend

src/backend/distributed/commands/citus_global_signal.c

@@ -87,10 +87,11 @@ CitusSignalBackend(uint64 globalPID, uint64 timeout, int sig)
 	}
 #endif
 
-	int nodeId = ExtractNodeIdFromGlobalPID(globalPID);
+	bool missingOk = false;
+	int nodeId = ExtractNodeIdFromGlobalPID(globalPID, missingOk);
 	int processId = ExtractProcessIdFromGlobalPID(globalPID);
 
-	WorkerNode *workerNode = FindNodeWithNodeId(nodeId);
+	WorkerNode *workerNode = FindNodeWithNodeId(nodeId, missingOk);
 
 	StringInfo cancelQuery = makeStringInfo();
 

src/backend/distributed/executor/citus_custom_scan.c

@@ -150,8 +150,6 @@ RegisterCitusCustomScanMethods(void)
 static void
 CitusBeginScan(CustomScanState *node, EState *estate, int eflags)
 {
-	MarkCitusInitiatedCoordinatorBackend();
-
 	CitusScanState *scanState = (CitusScanState *) node;
 
 	/*

src/backend/distributed/metadata/node_metadata.c

@@ -1541,7 +1541,7 @@ FindWorkerNodeAnyCluster(const char *nodeName, int32 nodePort)
  * If the node cannot be found this functions errors.
  */
 WorkerNode *
-FindNodeWithNodeId(int nodeId)
+FindNodeWithNodeId(int nodeId, bool missingOk)
 {
 	List *workerList = ActiveReadableNodeList();
 	WorkerNode *workerNode = NULL;
@@ -1555,7 +1555,10 @@ FindNodeWithNodeId(int nodeId)
 	}
 
 	/* there isn't any node with nodeId in pg_dist_node */
+	if (!missingOk)
+	{
 		elog(ERROR, "worker node with node id %d could not be found", nodeId);
+	}
 
 	return NULL;
 }

src/backend/distributed/transaction/backend_data.c

@@ -152,9 +152,6 @@ assign_distributed_transaction_id(PG_FUNCTION_ARGS)
 	MyBackendData->transactionId.timestamp = timestamp;
 	MyBackendData->transactionId.transactionOriginator = false;
 
-	MyBackendData->citusBackend.initiatorNodeIdentifier =
-		MyBackendData->transactionId.initiatorNodeIdentifier;
-
 	SpinLockRelease(&MyBackendData->mutex);
 
 	PG_RETURN_VOID();
@@ -385,7 +382,6 @@ StoreAllActiveTransactions(Tuplestorestate *tupleStore, TupleDesc tupleDescripto
 			&backendManagementShmemData->backends[backendIndex];
 
 		/* to work on data after releasing g spinlock to protect against errors */
-		int initiatorNodeIdentifier = -1;
 		uint64 transactionNumber = 0;
 
 		SpinLockAcquire(&currentBackend->mutex);
@@ -408,7 +404,6 @@ StoreAllActiveTransactions(Tuplestorestate *tupleStore, TupleDesc tupleDescripto
 
 		Oid databaseId = currentBackend->databaseId;
 		int backendPid = ProcGlobal->allProcs[backendIndex].pid;
-		initiatorNodeIdentifier = currentBackend->citusBackend.initiatorNodeIdentifier;
 
 		/*
 		 * We prefer to use worker_query instead of distributedCommandOriginator in
@@ -423,9 +418,12 @@ StoreAllActiveTransactions(Tuplestorestate *tupleStore, TupleDesc tupleDescripto
 
 		SpinLockRelease(&currentBackend->mutex);
 
+		bool missingOk = true;
+		int nodeId = ExtractNodeIdFromGlobalPID(currentBackend->globalPID, missingOk);
+
 		values[0] = ObjectIdGetDatum(databaseId);
 		values[1] = Int32GetDatum(backendPid);
-		values[2] = Int32GetDatum(initiatorNodeIdentifier);
+		values[2] = Int32GetDatum(nodeId);
 		values[3] = !distributedCommandOriginator;
 		values[4] = UInt64GetDatum(transactionNumber);
 		values[5] = TimestampTzGetDatum(transactionIdTimestamp);
@@ -520,7 +518,6 @@ BackendManagementShmemInit(void)
 		{
 			BackendData *backendData =
 				&backendManagementShmemData->backends[backendIndex];
-			backendData->citusBackend.initiatorNodeIdentifier = -1;
 			SpinLockInit(&backendData->mutex);
 		}
 	}
@@ -660,8 +657,6 @@ UnSetDistributedTransactionId(void)
 		MyBackendData->transactionId.transactionNumber = 0;
 		MyBackendData->transactionId.timestamp = 0;
 
-		MyBackendData->citusBackend.initiatorNodeIdentifier = -1;
-
 		SpinLockRelease(&MyBackendData->mutex);
 	}
 }
@@ -772,29 +767,6 @@ AssignDistributedTransactionId(void)
 	MyBackendData->transactionId.transactionNumber = nextTransactionNumber;
 	MyBackendData->transactionId.timestamp = currentTimestamp;
 
-	MyBackendData->citusBackend.initiatorNodeIdentifier = localGroupId;
-
-	SpinLockRelease(&MyBackendData->mutex);
-}
-
-
-/*
- * MarkCitusInitiatedCoordinatorBackend sets that coordinator backend is
- * initiated by Citus.
- */
-void
-MarkCitusInitiatedCoordinatorBackend(void)
-{
-	/*
-	 * GetLocalGroupId may throw exception which can cause leaving spin lock
-	 * unreleased. Calling GetLocalGroupId function before the lock to avoid this.
-	 */
-	int32 localGroupId = GetLocalGroupId();
-
-	SpinLockAcquire(&MyBackendData->mutex);
-
-	MyBackendData->citusBackend.initiatorNodeIdentifier = localGroupId;
-
 	SpinLockRelease(&MyBackendData->mutex);
 }
 
@@ -926,11 +898,12 @@ ExtractGlobalPID(char *applicationName)
  * gives us the node id.
  */
 int
-ExtractNodeIdFromGlobalPID(uint64 globalPID)
+ExtractNodeIdFromGlobalPID(uint64 globalPID, bool missingOk)
 {
 	int nodeId = (int) (globalPID / GLOBAL_PID_NODE_ID_MULTIPLIER);
 
-	if (nodeId == GLOBAL_PID_NODE_ID_FOR_NODES_NOT_IN_METADATA)
+	if (!missingOk &&
+		nodeId == GLOBAL_PID_NODE_ID_FOR_NODES_NOT_IN_METADATA)
 	{
 		ereport(ERROR, (errmsg("originator node of the query with the global pid "
 							   "%lu is not in Citus' metadata", globalPID),

src/backend/distributed/transaction/citus_dist_stat_activity.c

@@ -538,33 +538,35 @@ ReplaceInitiatorNodeIdentifier(int initiator_node_identifier,
 	 *     transaction. However, we cannot know which node has initiated
 	 *     the worker query.
 	 */
-	if (initiator_node_identifier > 0)
+	if (initiator_node_identifier == GLOBAL_PID_NODE_ID_FOR_NODES_NOT_IN_METADATA &&
-	{
+		IsCoordinator())
-		bool nodeExists = false;
-
-		initiatorWorkerNode = PrimaryNodeForGroup(initiator_node_identifier, &nodeExists);
-
-		/* a query should run on an existing node */
-		Assert(nodeExists);
-		if (initiatorWorkerNode == NULL)
-		{
-			ereport(ERROR, (errmsg("no primary node found for group %d",
-								   initiator_node_identifier)));
-		}
-		citusDistStat->master_query_host_name =
-			cstring_to_text(initiatorWorkerNode->workerName);
-		citusDistStat->master_query_host_port = initiatorWorkerNode->workerPort;
-	}
-	else if (initiator_node_identifier == 0 && IsCoordinator())
 	{
 		citusDistStat->master_query_host_name = cstring_to_text(coordinator_host_name);
 		citusDistStat->master_query_host_port = PostPortNumber;
 	}
-	else if (initiator_node_identifier == 0)
+	else if (initiator_node_identifier == GLOBAL_PID_NODE_ID_FOR_NODES_NOT_IN_METADATA)
 	{
 		citusDistStat->master_query_host_name = cstring_to_text(coordinator_host_name);
 		citusDistStat->master_query_host_port = 0;
 	}
+	else if (initiator_node_identifier > 0)
+	{
+		/* a query should run on an existing node, but lets be defensive */
+		bool missingOk = true;
+		initiatorWorkerNode = FindNodeWithNodeId(initiator_node_identifier, missingOk);
+
+		if (initiatorWorkerNode)
+		{
+			citusDistStat->master_query_host_name =
+				cstring_to_text(initiatorWorkerNode->workerName);
+			citusDistStat->master_query_host_port = initiatorWorkerNode->workerPort;
+		}
+		else
+		{
+			citusDistStat->master_query_host_name = NULL;
+			citusDistStat->master_query_host_port = 0;
+		}
+	}
 	else
 	{
 		citusDistStat->master_query_host_name = NULL;

src/include/distributed/backend_data.h

@@ -22,16 +22,6 @@
 #include "storage/s_lock.h"
 
 
-/*
- * CitusInitiatedBackend keeps some information about the backends that are
- * initiated by Citus.
- */
-typedef struct CitusInitiatedBackend
-{
-	int initiatorNodeIdentifier;
-} CitusInitiatedBackend;
-
-
 /*
  * Each backend's active distributed transaction information is tracked via
  * BackendData in shared memory.
@@ -51,7 +41,6 @@ typedef struct BackendData
 	bool cancelledDueToDeadlock;
 	uint64 globalPID;
 	bool distributedCommandOriginator;
-	CitusInitiatedBackend citusBackend;
 	DistributedTransactionId transactionId;
 } BackendData;
 
@@ -64,13 +53,12 @@ extern void UnlockBackendSharedMemory(void);
 extern void UnSetDistributedTransactionId(void);
 extern void UnSetGlobalPID(void);
 extern void AssignDistributedTransactionId(void);
-extern void MarkCitusInitiatedCoordinatorBackend(void);
 extern void AssignGlobalPID(void);
 extern uint64 GetGlobalPID(void);
 extern void OverrideBackendDataDistributedCommandOriginator(bool
 															distributedCommandOriginator);
 extern uint64 ExtractGlobalPID(char *applicationName);
-extern int ExtractNodeIdFromGlobalPID(uint64 globalPID);
+extern int ExtractNodeIdFromGlobalPID(uint64 globalPID, bool missingOk);
 extern int ExtractProcessIdFromGlobalPID(uint64 globalPID);
 extern void GetBackendDataForProc(PGPROC *proc, BackendData *result);
 extern void CancelTransactionDueToDeadlock(PGPROC *proc);

src/include/distributed/worker_manager.h

@@ -86,7 +86,7 @@ extern List * ActiveReadableNodeList(void);
 extern WorkerNode * FindWorkerNode(const char *nodeName, int32 nodePort);
 extern WorkerNode * FindWorkerNodeOrError(const char *nodeName, int32 nodePort);
 extern WorkerNode * FindWorkerNodeAnyCluster(const char *nodeName, int32 nodePort);
-extern WorkerNode * FindNodeWithNodeId(int nodeId);
+extern WorkerNode * FindNodeWithNodeId(int nodeId, bool missingOk);
 extern List * ReadDistNode(bool includeNodesFromOtherClusters);
 extern void EnsureCoordinator(void);
 extern void InsertCoordinatorIfClusterEmpty(void);

src/test/regress/expected/isolation_distributed_transaction_id.out

@@ -89,11 +89,11 @@ step s1-insert:
 step s1-verify-current-xact-is-on-worker:
 	SELECT
 	    remote.nodeport,
-     remote.result = row(xact.initiator_node_identifier, xact.transaction_number)::text AS xact_exists
+	    remote.result = row(xact.transaction_number)::text AS xact_exists
 	FROM
 	    get_current_transaction_id() as xact,
 	    run_command_on_workers($$
-         SELECT row(initiator_node_identifier, transaction_number)
+	        SELECT row(transaction_number)
             FROM get_all_active_transactions()
 			WHERE transaction_number != 0;
         $$) as remote

src/test/regress/expected/isolation_get_distributed_wait_queries_mx.out

@@ -33,7 +33,7 @@ blocked_statement                                  |current_statement_in_blockin
 ---------------------------------------------------------------------
 UPDATE ref_table SET value_1 = 12 WHERE user_id = 1|
 	UPDATE ref_table SET value_1 = 15;
-|localhost        |coordinator_host  |            57638|             57636
+|coordinator_host |coordinator_host  |            57636|             57636
 (1 row)
 
 step s1-commit:
@@ -116,7 +116,7 @@ step s3-select-distributed-waiting-queries:
 
 blocked_statement                                  |current_statement_in_blocking_process              |waiting_node_name|blocking_node_name|waiting_node_port|blocking_node_port
 ---------------------------------------------------------------------
-UPDATE ref_table SET value_1 = 12 WHERE user_id = 1|UPDATE ref_table SET value_1 = 12 WHERE user_id = 1|localhost        |localhost         |            57638|             57637
+UPDATE ref_table SET value_1 = 12 WHERE user_id = 1|UPDATE ref_table SET value_1 = 12 WHERE user_id = 1|coordinator_host |coordinator_host  |            57636|             57636
 (1 row)
 
 step s1-commit-worker:
@@ -212,7 +212,7 @@ step s3-select-distributed-waiting-queries:
 
 blocked_statement         |current_statement_in_blocking_process|waiting_node_name|blocking_node_name|waiting_node_port|blocking_node_port
 ---------------------------------------------------------------------
-UPDATE tt1 SET value_1 = 5|UPDATE tt1 SET value_1 = 4           |localhost        |localhost         |            57638|             57637
+UPDATE tt1 SET value_1 = 5|UPDATE tt1 SET value_1 = 4           |coordinator_host |coordinator_host  |            57636|             57636
 (1 row)
 
 step s1-commit-worker:
@@ -308,7 +308,7 @@ step s3-select-distributed-waiting-queries:
 
 blocked_statement                                  |current_statement_in_blocking_process  |waiting_node_name|blocking_node_name|waiting_node_port|blocking_node_port
 ---------------------------------------------------------------------
-UPDATE ref_table SET value_1 = 12 WHERE user_id = 1|DELETE FROM ref_table WHERE user_id = 1|localhost        |localhost         |            57638|             57637
+UPDATE ref_table SET value_1 = 12 WHERE user_id = 1|DELETE FROM ref_table WHERE user_id = 1|coordinator_host |coordinator_host  |            57636|             57636
 (1 row)
 
 step s1-commit-worker:
@@ -404,7 +404,7 @@ step s3-select-distributed-waiting-queries:
 
 blocked_statement                                  |current_statement_in_blocking_process    |waiting_node_name|blocking_node_name|waiting_node_port|blocking_node_port
 ---------------------------------------------------------------------
-UPDATE ref_table SET value_1 = 12 WHERE user_id = 1|INSERT INTO ref_table VALUES(8,81),(9,91)|localhost        |localhost         |            57638|             57637
+UPDATE ref_table SET value_1 = 12 WHERE user_id = 1|INSERT INTO ref_table VALUES(8,81),(9,91)|coordinator_host |coordinator_host  |            57636|             57636
 (1 row)
 
 step s1-commit-worker:
@@ -594,7 +594,7 @@ step s3-select-distributed-waiting-queries:
 
 blocked_statement                                  |current_statement_in_blocking_process                              |waiting_node_name|blocking_node_name|waiting_node_port|blocking_node_port
 ---------------------------------------------------------------------
-UPDATE ref_table SET value_1 = 12 WHERE user_id = 1|COPY ref_table FROM PROGRAM 'echo 10, 101 && echo 11, 111' WITH CSV|localhost        |localhost         |            57638|             57637
+UPDATE ref_table SET value_1 = 12 WHERE user_id = 1|COPY ref_table FROM PROGRAM 'echo 10, 101 && echo 11, 111' WITH CSV|coordinator_host |coordinator_host  |            57636|             57636
 (1 row)
 
 step s1-commit-worker:
@@ -878,7 +878,7 @@ step s3-select-distributed-waiting-queries:
 
 blocked_statement                                  |current_statement_in_blocking_process|waiting_node_name|blocking_node_name|waiting_node_port|blocking_node_port
 ---------------------------------------------------------------------
-UPDATE ref_table SET value_1 = 12 WHERE user_id = 1|SELECT * FROM ref_table FOR UPDATE   |localhost        |localhost         |            57638|             57637
+UPDATE ref_table SET value_1 = 12 WHERE user_id = 1|SELECT * FROM ref_table FOR UPDATE   |coordinator_host |coordinator_host  |            57636|             57636
 (1 row)
 
 step s1-commit-worker:
@@ -963,7 +963,7 @@ blocked_statement                                                     |current_s
 ---------------------------------------------------------------------
 
 	ALTER TABLE ref_table ADD CONSTRAINT rf_p_key PRIMARY KEY(user_id);
-|INSERT INTO ref_table VALUES(8,81),(9,91)|coordinator_host |localhost         |            57636|             57638
+|INSERT INTO ref_table VALUES(8,81),(9,91)|coordinator_host |coordinator_host  |            57636|             57636
 (1 row)
 
 step s2-commit-worker:
@@ -1073,7 +1073,7 @@ step s3-select-distributed-waiting-queries:
 
 blocked_statement         |current_statement_in_blocking_process|waiting_node_name|blocking_node_name|waiting_node_port|blocking_node_port
 ---------------------------------------------------------------------
-UPDATE tt1 SET value_1 = 5|UPDATE tt1 SET value_1 = 4           |localhost        |localhost         |            57637|             57637
+UPDATE tt1 SET value_1 = 5|UPDATE tt1 SET value_1 = 4           |coordinator_host |coordinator_host  |            57636|             57636
 (1 row)
 
 step s1-commit-worker:
@@ -1161,7 +1161,7 @@ step s3-select-distributed-waiting-queries:
 
 blocked_statement                           |current_statement_in_blocking_process       |waiting_node_name|blocking_node_name|waiting_node_port|blocking_node_port
 ---------------------------------------------------------------------
-UPDATE tt1 SET value_1 = 4 WHERE user_id = 1|UPDATE tt1 SET value_1 = 4 WHERE user_id = 1|localhost        |localhost         |            57638|             57637
+UPDATE tt1 SET value_1 = 4 WHERE user_id = 1|UPDATE tt1 SET value_1 = 4 WHERE user_id = 1|coordinator_host |coordinator_host  |            57636|             57636
 (1 row)
 
 step s1-commit-worker:
@@ -1225,7 +1225,7 @@ blocked_statement                                  |current_statement_in_blockin
 ---------------------------------------------------------------------
 UPDATE ref_table SET value_1 = 12 WHERE user_id = 1|
 	UPDATE ref_table SET value_1 = 15;
-|localhost        |coordinator_host  |            57638|             57636
+|coordinator_host |coordinator_host  |            57636|             57636
 (1 row)
 
 step s1-commit:

src/test/regress/expected/isolation_replicate_reference_tables_to_coordinator.out

@@ -1,11 +1,19 @@
-Parsed test spec with 3 sessions
+Parsed test spec with 4 sessions
 
-starting permutation: s1-begin s2-begin s1-update-dist-table s2-lock-ref-table-placement-on-coordinator s1-lock-ref-table-placement-on-coordinator s2-update-dist-table deadlock-checker-call s1-end s2-end
+starting permutation: add-node s1-begin s2-begin s1-update-dist-table s2-lock-ref-table-placement-on-coordinator s1-lock-ref-table-placement-on-coordinator s2-update-dist-table deadlock-checker-call s1-end s2-end
 create_distributed_table
 ---------------------------------------------------------------------
 
 (1 row)
 
+step add-node:
+  SELECT 1 FROM master_add_node('localhost', 57636, groupid => 0);
+
+?column?
+---------------------------------------------------------------------
+       1
+(1 row)
+
 step s1-begin:
     BEGIN;
 
@@ -59,12 +67,20 @@ master_remove_node
 (1 row)
 
 
-starting permutation: s1-begin s2-begin s1-update-ref-table s2-sleep s2-view-dist s2-view-worker s2-end s1-end
+starting permutation: add-node s1-begin s2-begin s1-update-ref-table s2-sleep s2-view-dist s2-view-worker s2-end s1-end
 create_distributed_table
 ---------------------------------------------------------------------
 
 (1 row)
 
+step add-node:
+  SELECT 1 FROM master_add_node('localhost', 57636, groupid => 0);
+
+?column?
+---------------------------------------------------------------------
+       1
+(1 row)
+
 step s1-begin:
     BEGIN;
 
@@ -83,7 +99,7 @@ pg_sleep
 (1 row)
 
 step s2-view-dist:
-        SELECT query, query_hostname, query_hostport, distributed_query_host_name, distributed_query_host_port, state, wait_event_type, wait_event, usename, datname FROM citus_dist_stat_activity WHERE query NOT ILIKE '%pg_prepared_xacts%' AND query NOT ILIKE '%COMMIT%' AND query NOT ILIKE '%pg_isolation_test_session_is_blocked%' AND query NOT ILIKE '%BEGIN%' ORDER BY query DESC;
+        SELECT query, query_hostname, query_hostport, distributed_query_host_name, distributed_query_host_port, state, wait_event_type, wait_event, usename, datname FROM citus_dist_stat_activity WHERE query NOT ILIKE '%pg_prepared_xacts%' AND query NOT ILIKE '%COMMIT%' AND query NOT ILIKE '%pg_isolation_test_session_is_blocked%' AND query NOT ILIKE '%BEGIN%' AND query NOT ILIKE '%add_node%' ORDER BY query DESC;
 
 query                                    |query_hostname  |query_hostport|distributed_query_host_name|distributed_query_host_port|state              |wait_event_type|wait_event|usename |datname
 ---------------------------------------------------------------------
@@ -92,7 +108,7 @@ query                                    |query_hostname  |query_hostport|distri
 |coordinator_host|         57636|                           |                          0|idle               |Client         |ClientRead|postgres|regression
 
     update ref_table set a = a + 1;
-    |coordinator_host|         57636|coordinator_host           |                      57636|idle in transaction|Client         |ClientRead|postgres|regression
+    |coordinator_host|         57636|                           |                          0|idle in transaction|Client         |ClientRead|postgres|regression
 (2 rows)
 
 step s2-view-worker:
@@ -102,13 +118,14 @@ step s2-view-worker:
     WHERE query NOT ILIKE '%pg_prepared_xacts%' AND
           query NOT ILIKE '%COMMIT%' AND
           query NOT ILIKE '%dump_local_%' AND
-          query NOT ILIKE '%citus_internal_local_blocked_processes%'
+          query NOT ILIKE '%citus_internal_local_blocked_processes%' AND
+          query NOT ILIKE '%add_node%'
     ORDER BY query, query_hostport DESC;
 
 query                                                                        |query_hostname|query_hostport|distributed_query_host_name|distributed_query_host_port|state              |wait_event_type|wait_event|usename |datname
 ---------------------------------------------------------------------
-UPDATE public.ref_table_1500777 ref_table SET a = (a OPERATOR(pg_catalog.+) 1)|localhost     |         57638|coordinator_host           |                      57636|idle in transaction|Client         |ClientRead|postgres|regression
+UPDATE public.ref_table_1500777 ref_table SET a = (a OPERATOR(pg_catalog.+) 1)|localhost     |         57638|                           |                          0|idle in transaction|Client         |ClientRead|postgres|regression
-UPDATE public.ref_table_1500777 ref_table SET a = (a OPERATOR(pg_catalog.+) 1)|localhost     |         57637|coordinator_host           |                      57636|idle in transaction|Client         |ClientRead|postgres|regression
+UPDATE public.ref_table_1500777 ref_table SET a = (a OPERATOR(pg_catalog.+) 1)|localhost     |         57637|                           |                          0|idle in transaction|Client         |ClientRead|postgres|regression
 (2 rows)
 
 step s2-end:
@@ -123,12 +140,20 @@ master_remove_node
 (1 row)
 
 
-starting permutation: s1-begin s2-begin s1-update-ref-table s2-active-transactions s1-end s2-end
+starting permutation: add-node s1-begin s2-begin s1-update-ref-table s2-active-transactions s1-end s2-end
 create_distributed_table
 ---------------------------------------------------------------------
 
 (1 row)
 
+step add-node:
+  SELECT 1 FROM master_add_node('localhost', 57636, groupid => 0);
+
+?column?
+---------------------------------------------------------------------
+       1
+(1 row)
+
 step s1-begin:
     BEGIN;
 

src/test/regress/spec/isolation_distributed_transaction_id.spec

@@ -49,11 +49,11 @@ step "s1-verify-current-xact-is-on-worker"
 {
 	SELECT
 	    remote.nodeport,
-	    remote.result = row(xact.initiator_node_identifier, xact.transaction_number)::text AS xact_exists
+	    remote.result = row(xact.transaction_number)::text AS xact_exists
 	FROM
 	    get_current_transaction_id() as xact,
 	    run_command_on_workers($$
-	        SELECT row(initiator_node_identifier, transaction_number)
+	        SELECT row(transaction_number)
             FROM get_all_active_transactions()
 			WHERE transaction_number != 0;
         $$) as remote

src/test/regress/spec/isolation_metadata_sync_vs_all.spec

@@ -29,7 +29,6 @@ setup
 
 teardown
 {
-	// drop all distributed tables
 	DROP TABLE IF EXISTS ref_table,
 						 dist_table,
 						 dist_partitioned_table,
@@ -39,7 +38,6 @@ teardown
 						 new_ref_table;
 
 
-	// drop all distributed objects
 	DROP FUNCTION activate_node_snapshot();
 	DROP FUNCTION IF EXISTS squares(int);
 	DROP TYPE IF EXISTS my_type;

src/test/regress/spec/isolation_replicate_reference_tables_to_coordinator.spec

@@ -3,8 +3,6 @@ setup
   SELECT citus_internal.replace_isolation_tester_func();
   SELECT citus_internal.refresh_isolation_tester_prepared_statement();
 
-  SELECT master_add_node('localhost', 57636, groupid => 0);
-
   CREATE TABLE ref_table(a int primary key);
   SELECT create_reference_table('ref_table');
   INSERT INTO ref_table VALUES (1), (3), (5), (7);
@@ -83,7 +81,7 @@ step "s2-lock-ref-table-placement-on-coordinator"
 
 step "s2-view-dist"
 {
-        SELECT query, query_hostname, query_hostport, distributed_query_host_name, distributed_query_host_port, state, wait_event_type, wait_event, usename, datname FROM citus_dist_stat_activity WHERE query NOT ILIKE '%pg_prepared_xacts%' AND query NOT ILIKE '%COMMIT%' AND query NOT ILIKE '%pg_isolation_test_session_is_blocked%' AND query NOT ILIKE '%BEGIN%' ORDER BY query DESC;
+        SELECT query, query_hostname, query_hostport, distributed_query_host_name, distributed_query_host_port, state, wait_event_type, wait_event, usename, datname FROM citus_dist_stat_activity WHERE query NOT ILIKE '%pg_prepared_xacts%' AND query NOT ILIKE '%COMMIT%' AND query NOT ILIKE '%pg_isolation_test_session_is_blocked%' AND query NOT ILIKE '%BEGIN%' AND query NOT ILIKE '%add_node%' ORDER BY query DESC;
 }
 
 step "s2-view-worker"
@@ -94,7 +92,8 @@ step "s2-view-worker"
     WHERE query NOT ILIKE '%pg_prepared_xacts%' AND
           query NOT ILIKE '%COMMIT%' AND
           query NOT ILIKE '%dump_local_%' AND
-          query NOT ILIKE '%citus_internal_local_blocked_processes%'
+          query NOT ILIKE '%citus_internal_local_blocked_processes%' AND
+          query NOT ILIKE '%add_node%'
     ORDER BY query, query_hostport DESC;
 }
 
@@ -123,14 +122,25 @@ step "deadlock-checker-call"
   SELECT check_distributed_deadlocks();
 }
 
+
+// adding node in setup stage prevents getting a gpid with proper nodeid
+session "add-node"
+
+// we issue the checker not only when there are deadlocks to ensure that we never cancel
+// backend inappropriately
+step "add-node"
+{
+  SELECT 1 FROM master_add_node('localhost', 57636, groupid => 0);
+}
+
 // verify that locks on the placement of the reference table on the coordinator is
 // taken into account when looking for distributed deadlocks
-permutation "s1-begin" "s2-begin" "s1-update-dist-table" "s2-lock-ref-table-placement-on-coordinator" "s1-lock-ref-table-placement-on-coordinator" "s2-update-dist-table" "deadlock-checker-call" "s1-end" "s2-end"
+permutation "add-node" "s1-begin" "s2-begin" "s1-update-dist-table" "s2-lock-ref-table-placement-on-coordinator" "s1-lock-ref-table-placement-on-coordinator" "s2-update-dist-table" "deadlock-checker-call" "s1-end" "s2-end"
 
 // verify that *_dist_stat_activity() functions return the correct result when query
 // has a task on the coordinator.
-permutation "s1-begin" "s2-begin" "s1-update-ref-table" "s2-sleep" "s2-view-dist" "s2-view-worker" "s2-end" "s1-end"
+permutation "add-node" "s1-begin" "s2-begin" "s1-update-ref-table" "s2-sleep" "s2-view-dist" "s2-view-worker" "s2-end" "s1-end"
 
 // verify that get_*_active_transactions() functions return the correct result when
 // the query has a task on the coordinator.
-permutation "s1-begin" "s2-begin" "s1-update-ref-table" "s2-active-transactions" "s1-end" "s2-end"
+permutation "add-node" "s1-begin" "s2-begin" "s1-update-ref-table" "s2-active-transactions" "s1-end" "s2-end"