Revert "Fixes flakiness in multi_metadata_sync test (#6824)"

This reverts commit 6cfcc3709ffe1e869e4b606fd592a0b63cfbc66a.
2023-04-10 16:12:03 +03:00 · 2023-04-10 16:12:03 +03:00 · 1aea5b1a51
parent b49cd144b0
commit 1aea5b1a51
42 changed files with 270 additions and 1789 deletions
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@ -6,7 +6,7 @@ orbs:
 parameters:
  image_suffix:
    type: string
-    default: '-v3417e8d'
+    default: '-v087ecd7'
  pg13_version:
    type: string
    default: '13.10'
@ -490,6 +490,10 @@ jobs:
          pg_major: << parameters.pg_major >>
      - configure
      - enable_core
+      - run:
+          name: 'Install DBI.pm'
+          command: |
+            apt-get update && apt-get install libdbi-perl && apt-get install libdbd-pg-perl
      - run:
          name: 'Run Test'
          command: |
--- a/src/backend/distributed/Makefile
+++ b/src/backend/distributed/Makefile
@ -37,7 +37,8 @@ OBJS += \
 all: cdc

 cdc:
-	$(MAKE) -C cdc all
+	echo "running cdc make"
+	$(MAKE) DECODER=pgoutput -C cdc all

 NO_PGXS = 1

@ -84,13 +85,12 @@ ifneq (,$(SQL_Po_files))
 include $(SQL_Po_files)
 endif

-
-.PHONY: clean-full install install-downgrades install-all install-cdc clean-cdc
+.PHONY: clean-full install install-downgrades install-all

 clean: clean-cdc

 clean-cdc:
-	$(MAKE) -C cdc clean
+	$(MAKE) DECODER=pgoutput -C cdc clean

 cleanup-before-install:
 	rm -f $(DESTDIR)$(datadir)/$(datamoduledir)/citus.control
@ -99,7 +99,7 @@ cleanup-before-install:
 install: cleanup-before-install install-cdc

 install-cdc:
-	$(MAKE) -C cdc install
+	$(MAKE) DECODER=pgoutput -C cdc install

 # install and install-downgrades should be run sequentially
 install-all: install
--- a/src/backend/distributed/cdc/Makefile
+++ b/src/backend/distributed/cdc/Makefile
@ -1,45 +1,26 @@
+ifndef DECODER
+	DECODER = pgoutput
+endif
+
+MODULE_big = citus_$(DECODER)
+citus_subdir = src/backend/distributed/cdc
 citus_top_builddir = ../../../..
+citus_decoders_dir = $(DESTDIR)$(pkglibdir)/citus_decoders
+
+OBJS += cdc_decoder.o cdc_decoder_utils.o
+
 include $(citus_top_builddir)/Makefile.global

-citus_subdir = src/backend/distributed/cdc
-SRC_DIR = $(citus_abs_top_srcdir)/$(citus_subdir)
+override CFLAGS += -DDECODER=\"$(DECODER)\" -I$(citus_abs_top_srcdir)/include
+override CPPFLAGS += -DDECODER=\"$(DECODER)\" -I$(citus_abs_top_srcdir)/include

-#List of supported based decoders. Add new decoders here.
-cdc_base_decoders :=pgoutput wal2json
+install: install-cdc

-all: build-cdc-decoders
+clean: clean-cdc

-copy-decoder-files-to-build-dir:
-	$(eval DECODER_BUILD_DIR=build-cdc-$(DECODER))
-	mkdir -p $(DECODER_BUILD_DIR)
-	@for file in $(SRC_DIR)/*.c $(SRC_DIR)/*.h; do \
-		if [ -f $$file ]; then \
-			if [ -f $(DECODER_BUILD_DIR)/$$(basename $$file) ]; then \
-				if ! diff -q $$file $(DECODER_BUILD_DIR)/$$(basename $$file); then \
-					cp $$file $(DECODER_BUILD_DIR)/$$(basename $$file); \
-				fi \
-			else \
-				cp $$file $(DECODER_BUILD_DIR)/$$(basename $$file); \
-			fi \
-		fi \
-	done
-	cp $(SRC_DIR)/Makefile.decoder $(DECODER_BUILD_DIR)/Makefile
-
-build-cdc-decoders:
-	$(foreach base_decoder,$(cdc_base_decoders),$(MAKE) DECODER=$(base_decoder) build-cdc-decoder;)
-
-install-cdc-decoders:
-	$(foreach base_decoder,$(cdc_base_decoders),$(MAKE) DECODER=$(base_decoder) -C build-cdc-$(base_decoder) install;)
-
-clean-cdc-decoders:
-	$(foreach base_decoder,$(cdc_base_decoders),rm -rf build-cdc-$(base_decoder);)
-
-
-build-cdc-decoder:
-	$(MAKE) DECODER=$(DECODER) copy-decoder-files-to-build-dir
-	$(MAKE) DECODER=$(DECODER) -C build-cdc-$(DECODER)
-
-install: install-cdc-decoders
-
-clean: clean-cdc-decoders
+install-cdc:
+	mkdir -p '$(citus_decoders_dir)'
+	$(INSTALL_SHLIB) citus_$(DECODER).so '$(citus_decoders_dir)/$(DECODER).so'

+clean-cdc:
+	rm -f '$(DESTDIR)$(datadir)/$(datamoduledir)/citus_decoders/$(DECODER).so'
--- a/src/backend/distributed/cdc/Makefile.decoder
+++ b/src/backend/distributed/cdc/Makefile.decoder
@ -1,24 +0,0 @@
-MODULE_big = citus_$(DECODER)
-
-citus_decoders_dir = $(DESTDIR)$(pkglibdir)/citus_decoders
-
-citus_top_builddir = ../../../../..
-citus_subdir = src/backend/distributed/cdc/cdc_$(DECODER)
-
-OBJS += cdc_decoder.o cdc_decoder_utils.o
-
-include $(citus_top_builddir)/Makefile.global
-
-override CFLAGS += -DDECODER=\"$(DECODER)\" -I$(citus_abs_top_srcdir)/include
-override CPPFLAGS += -DDECODER=\"$(DECODER)\" -I$(citus_abs_top_srcdir)/include
-
-install: install-cdc
-
-clean: clean-cdc
-
-install-cdc:
-	mkdir -p '$(citus_decoders_dir)'
-	$(INSTALL_SHLIB) citus_$(DECODER).so '$(citus_decoders_dir)/$(DECODER).so'
-
-clean-cdc:
-	rm -f '$(DESTDIR)$(datadir)/$(datamoduledir)/citus_decoders/$(DECODER).so'
--- a/src/backend/distributed/metadata/metadata_utility.c
+++ b/src/backend/distributed/metadata/metadata_utility.c
@ -32,7 +32,6 @@
 #include "catalog/pg_type.h"
 #include "commands/extension.h"
 #include "commands/sequence.h"
-#include "distributed/background_jobs.h"
 #include "distributed/colocation_utils.h"
 #include "distributed/connection_management.h"
 #include "distributed/citus_nodes.h"
@ -58,9 +57,7 @@
 #include "distributed/relay_utility.h"
 #include "distributed/resource_lock.h"
 #include "distributed/remote_commands.h"
-#include "distributed/shard_rebalancer.h"
 #include "distributed/tuplestore.h"
-#include "distributed/utils/array_type.h"
 #include "distributed/worker_manager.h"
 #include "distributed/worker_protocol.h"
 #include "distributed/version_compat.h"
@ -780,6 +777,7 @@ GenerateSizeQueryOnMultiplePlacements(List *shardIntervalList,
 		{
 			partitionedShardNames = lappend(partitionedShardNames, quotedShardName);
 		}
+
 		/* for non-partitioned tables, we will use Postgres' size functions */
 		else
 		{
@ -2818,8 +2816,7 @@ CreateBackgroundJob(const char *jobType, const char *description)
 */
 BackgroundTask *
 ScheduleBackgroundTask(int64 jobId, Oid owner, char *command, int dependingTaskCount,
-					   int64 dependingTaskIds[], int nodesInvolvedCount, int32
-					   nodesInvolved[])
+					   int64 dependingTaskIds[])
 {
 	BackgroundTask *task = NULL;

@ -2893,11 +2890,6 @@ ScheduleBackgroundTask(int64 jobId, Oid owner, char *command, int dependingTaskC
 		values[Anum_pg_dist_background_task_message - 1] = CStringGetTextDatum("");
 		nulls[Anum_pg_dist_background_task_message - 1] = false;

-		values[Anum_pg_dist_background_task_nodes_involved - 1] =
-			IntArrayToDatum(nodesInvolvedCount, nodesInvolved);
-		nulls[Anum_pg_dist_background_task_nodes_involved - 1] = (nodesInvolvedCount ==
-																  0);
-
 		HeapTuple newTuple = heap_form_tuple(RelationGetDescr(pgDistBackgroundTask),
 											 values, nulls);
 		CatalogTupleInsert(pgDistBackgroundTask, newTuple);
@ -3209,13 +3201,6 @@ DeformBackgroundTaskHeapTuple(TupleDesc tupleDescriptor, HeapTuple taskTuple)
 			TextDatumGetCString(values[Anum_pg_dist_background_task_message - 1]);
 	}

-	if (!nulls[Anum_pg_dist_background_task_nodes_involved - 1])
-	{
-		ArrayType *nodesInvolvedArrayObject =
-			DatumGetArrayTypeP(values[Anum_pg_dist_background_task_nodes_involved - 1]);
-		task->nodesInvolved = IntegerArrayTypeToList(nodesInvolvedArrayObject);
-	}
-
 	return task;
 }

@ -3348,8 +3333,7 @@ GetRunnableBackgroundTask(void)
 		while (HeapTupleIsValid(taskTuple = systable_getnext(scanDescriptor)))
 		{
 			task = DeformBackgroundTaskHeapTuple(tupleDescriptor, taskTuple);
-			if (BackgroundTaskReadyToRun(task) &&
-				IncrementParallelTaskCountForNodesInvolved(task))
+			if (BackgroundTaskReadyToRun(task))
 			{
 				/* found task, close table and return */
 				break;
--- a/src/backend/distributed/operations/shard_rebalancer.c
+++ b/src/backend/distributed/operations/shard_rebalancer.c
@ -190,32 +190,13 @@ typedef struct WorkerShardStatistics
 	HTAB *statistics;
 } WorkerShardStatistics;

-/*
- * ShardMoveDependencyHashEntry contains the taskId which any new shard
- * move task within the corresponding colocation group
- * must take a dependency on
- */
+/* ShardMoveDependencyHashEntry contains the taskId which any new shard move task within the corresponding colocation group must take a dependency on */
 typedef struct ShardMoveDependencyInfo
 {
 	int64 key;
 	int64 taskId;
 } ShardMoveDependencyInfo;

-/*
- * ShardMoveSourceNodeHashEntry keeps track of the source nodes
- * of the moves.
- */
-typedef struct ShardMoveSourceNodeHashEntry
-{
-	/* this is the key */
-	int32 node_id;
-	List *taskIds;
-} ShardMoveSourceNodeHashEntry;
-
-/*
- * ShardMoveDependencies keeps track of all needed dependencies
- * between shard moves.
- */
 typedef struct ShardMoveDependencies
 {
 	HTAB *colocationDependencies;
@ -293,15 +274,6 @@ static void AddToWorkerShardIdSet(HTAB *shardsByWorker, char *workerName, int wo
 static HTAB * BuildShardSizesHash(ProgressMonitorData *monitor, HTAB *shardStatistics);
 static void ErrorOnConcurrentRebalance(RebalanceOptions *);
 static List * GetSetCommandListForNewConnections(void);
-static int64 GetColocationId(PlacementUpdateEvent *move);
-static ShardMoveDependencies InitializeShardMoveDependencies();
-static int64 * GenerateTaskMoveDependencyList(PlacementUpdateEvent *move, int64
-											  colocationId,
-											  ShardMoveDependencies shardMoveDependencies,
-											  int *nDepends);
-static void UpdateShardMoveDependencies(PlacementUpdateEvent *move, uint64 colocationId,
-										int64 taskId,
-										ShardMoveDependencies shardMoveDependencies);

 /* declarations for dynamic loading */
 PG_FUNCTION_INFO_V1(rebalance_table_shards);
@ -1958,7 +1930,8 @@ GetColocationId(PlacementUpdateEvent *move)
 * InitializeShardMoveDependencies function creates the hash maps that we use to track
 * the latest moves so that subsequent moves with the same properties must take a dependency
 * on them. There are two hash maps. One is for tracking the latest move scheduled in a
- * given colocation group and the other one is for tracking source nodes of all moves.
+ * given colocation group and the other one is for tracking the latest move which involves
+ * a given node either as its source node or its target node.
 */
 static ShardMoveDependencies
 InitializeShardMoveDependencies()
@ -1968,17 +1941,18 @@ InitializeShardMoveDependencies()
 																				   ShardMoveDependencyInfo,
 																				   "colocationDependencyHashMap",
 																				   6);
-	shardMoveDependencies.nodeDependencies = CreateSimpleHashWithNameAndSize(int32,
-																			 ShardMoveSourceNodeHashEntry,
+	shardMoveDependencies.nodeDependencies = CreateSimpleHashWithNameAndSize(int64,
+																			 ShardMoveDependencyInfo,
 																			 "nodeDependencyHashMap",
 																			 6);
+
 	return shardMoveDependencies;
 }


 /*
 * GenerateTaskMoveDependencyList creates and returns a List of taskIds that
- * the move must take a dependency on, given the shard move dependencies as input.
+ * the move must take a dependency on.
 */
 static int64 *
 GenerateTaskMoveDependencyList(PlacementUpdateEvent *move, int64 colocationId,
@ -1998,24 +1972,27 @@ GenerateTaskMoveDependencyList(PlacementUpdateEvent *move, int64 colocationId,
 		hash_search(dependsList, &shardMoveDependencyInfo->taskId, HASH_ENTER, NULL);
 	}

-	/*
-	 * Check if there exists moves scheduled earlier whose source node
-	 * overlaps with the current move's target node.
-	 * The earlier/first move might make space for the later/second move.
-	 * So we could run out of disk space (or at least overload the node)
-	 * if we move the second shard to it before the first one is moved away. 
-	 */
-	ShardMoveSourceNodeHashEntry *shardMoveSourceNodeHashEntry = hash_search(
-		shardMoveDependencies.nodeDependencies, &move->targetNode->nodeId, HASH_FIND,
+	/* Check if there exists a move scheduled earlier whose source or target node
+	 * overlaps with the current move's source node. */
+	shardMoveDependencyInfo = hash_search(
+		shardMoveDependencies.nodeDependencies, &move->sourceNode->nodeId, HASH_ENTER,
 		&found);

 	if (found)
 	{
-		int64 *taskId = NULL;
-		foreach_ptr(taskId, shardMoveSourceNodeHashEntry->taskIds)
-		{
-			hash_search(dependsList, taskId, HASH_ENTER, NULL);
+		hash_search(dependsList, &shardMoveDependencyInfo->taskId, HASH_ENTER, NULL);
 	}
+
+	/* Check if there exists a move scheduled earlier whose source or target node
+	 * overlaps with the current move's target node. */
+	shardMoveDependencyInfo = hash_search(
+		shardMoveDependencies.nodeDependencies, &move->targetNode->nodeId, HASH_ENTER,
+		&found);
+
+
+	if (found)
+	{
+		hash_search(dependsList, &shardMoveDependencyInfo->taskId, HASH_ENTER, NULL);
 	}

 	*nDepends = hash_get_num_entries(dependsList);
@ -2053,20 +2030,15 @@ UpdateShardMoveDependencies(PlacementUpdateEvent *move, uint64 colocationId, int
 		shardMoveDependencies.colocationDependencies, &colocationId, HASH_ENTER, NULL);
 	shardMoveDependencyInfo->taskId = taskId;

-	bool found;
-	ShardMoveSourceNodeHashEntry *shardMoveSourceNodeHashEntry = hash_search(
-		shardMoveDependencies.nodeDependencies, &move->sourceNode->nodeId, HASH_ENTER,
-		&found);
+	shardMoveDependencyInfo = hash_search(shardMoveDependencies.nodeDependencies,
+										  &move->sourceNode->nodeId, HASH_ENTER, NULL);

-	if (!found)
-	{
-		shardMoveSourceNodeHashEntry->taskIds = NIL;
-	}
+	shardMoveDependencyInfo->taskId = taskId;

-	int64 *newTaskId = palloc0(sizeof(int64));
-	*newTaskId = taskId;
-	shardMoveSourceNodeHashEntry->taskIds = lappend(
-		shardMoveSourceNodeHashEntry->taskIds, newTaskId);
+	shardMoveDependencyInfo = hash_search(shardMoveDependencies.nodeDependencies,
+										  &move->targetNode->nodeId, HASH_ENTER, NULL);
+
+	shardMoveDependencyInfo->taskId = taskId;
 }


@ -2163,10 +2135,8 @@ RebalanceTableShardsBackground(RebalanceOptions *options, Oid shardReplicationMo
 		appendStringInfo(&buf,
 						 "SELECT pg_catalog.replicate_reference_tables(%s)",
 						 quote_literal_cstr(shardTranferModeLabel));
-
-		int32 nodesInvolved[] = { 0 };
 		BackgroundTask *task = ScheduleBackgroundTask(jobId, GetUserId(), buf.data, 0,
-													  NULL, 0, nodesInvolved);
+													  NULL);
 		replicateRefTablesTaskId = task->taskid;
 	}

@ -2200,14 +2170,9 @@ RebalanceTableShardsBackground(RebalanceOptions *options, Oid shardReplicationMo
 			dependsArray[0] = replicateRefTablesTaskId;
 		}

-		int32 nodesInvolved[2] = { 0 };
-		nodesInvolved[0] = move->sourceNode->nodeId;
-		nodesInvolved[1] = move->targetNode->nodeId;
-
 		BackgroundTask *task = ScheduleBackgroundTask(jobId, GetUserId(), buf.data,
 													  nDepends,
-													  dependsArray, 2,
-													  nodesInvolved);
+													  dependsArray);

 		UpdateShardMoveDependencies(move, colocationId, task->taskid,
 									shardMoveDependencies);
--- a/src/backend/distributed/shared_library_init.c
+++ b/src/backend/distributed/shared_library_init.c
@ -1793,18 +1793,6 @@ RegisterCitusConfigVariables(void)
 		GUC_STANDARD,
 		NULL, NULL, NULL);

-	DefineCustomIntVariable(
-		"citus.max_background_task_executors_per_node",
-		gettext_noop(
-			"Sets the maximum number of parallel background task executor workers "
-			"for scheduled background tasks that involve a particular node"),
-		NULL,
-		&MaxBackgroundTaskExecutorsPerNode,
-		1, 1, 128,
-		PGC_SIGHUP,
-		GUC_STANDARD,
-		NULL, NULL, NULL);
-
 	DefineCustomIntVariable(
 		"citus.max_cached_connection_lifetime",
 		gettext_noop("Sets the maximum lifetime of cached connections to other nodes."),
--- a/src/backend/distributed/sql/citus--11.2-1--11.2-2.sql
+++ b/src/backend/distributed/sql/citus--11.2-1--11.2-2.sql
@ -1,2 +0,0 @@
-- citus--11.2-1--11.2-2
-#include "udfs/worker_adjust_identity_column_seq_ranges/11.2-2.sql"
--- a/src/backend/distributed/sql/citus--11.2-1--11.3-1.sql
+++ b/src/backend/distributed/sql/citus--11.2-1--11.3-1.sql
@ -1,5 +1,6 @@
 -- citus--11.2-1--11.3-1
 #include "udfs/repl_origin_helper/11.3-1.sql"
+#include "udfs/worker_adjust_identity_column_seq_ranges/11.3-1.sql"
 ALTER TABLE pg_catalog.pg_dist_authinfo REPLICA IDENTITY USING INDEX pg_dist_authinfo_identification_index;
 ALTER TABLE pg_catalog.pg_dist_partition REPLICA IDENTITY USING INDEX pg_dist_partition_logical_relid_index;
 ALTER TABLE pg_catalog.pg_dist_placement REPLICA IDENTITY USING INDEX pg_dist_placement_placementid_index;
@ -14,7 +15,3 @@ ALTER TABLE pg_catalog.pg_dist_transaction REPLICA IDENTITY USING INDEX pg_dist_

 #include "udfs/citus_stat_tenants_local_reset/11.3-1.sql"
 #include "udfs/citus_stat_tenants_reset/11.3-1.sql"
-
-- we introduce nodes_involved, which will be used internally to
-- limit the number of parallel tasks running per node
-ALTER TABLE pg_catalog.pg_dist_background_task ADD COLUMN nodes_involved int[] DEFAULT NULL;
--- a/src/backend/distributed/sql/downgrades/citus--11.2-2--11.2-1.sql
+++ b/src/backend/distributed/sql/downgrades/citus--11.2-2--11.2-1.sql
@ -1,2 +0,0 @@
-- citus--11.2-2--11.2-1
-DROP FUNCTION IF EXISTS pg_catalog.worker_adjust_identity_column_seq_ranges(regclass);
--- a/src/backend/distributed/sql/downgrades/citus--11.3-1--11.2-1.sql
+++ b/src/backend/distributed/sql/downgrades/citus--11.3-1--11.2-1.sql
@ -3,6 +3,7 @@
 DROP FUNCTION pg_catalog.citus_internal_start_replication_origin_tracking();
 DROP FUNCTION pg_catalog.citus_internal_stop_replication_origin_tracking();
 DROP FUNCTION pg_catalog.citus_internal_is_replication_origin_tracking_active();
+DROP FUNCTION IF EXISTS pg_catalog.worker_adjust_identity_column_seq_ranges(regclass);
 ALTER TABLE pg_catalog.pg_dist_authinfo REPLICA IDENTITY NOTHING;
 ALTER TABLE pg_catalog.pg_dist_partition REPLICA IDENTITY NOTHING;
 ALTER TABLE pg_catalog.pg_dist_placement REPLICA IDENTITY NOTHING;
@ -28,5 +29,3 @@ DROP FUNCTION pg_catalog.citus_stat_tenants(boolean);

 DROP FUNCTION pg_catalog.citus_stat_tenants_local_reset();
 DROP FUNCTION pg_catalog.citus_stat_tenants_reset();
-
-ALTER TABLE pg_catalog.pg_dist_background_task DROP COLUMN nodes_involved;
--- a/src/backend/distributed/sql/udfs/worker_adjust_identity_column_seq_ranges/11.2-2.sql
+++ b/src/backend/distributed/sql/udfs/worker_adjust_identity_column_seq_ranges/11.2-2.sql
@ -1,3 +0,0 @@
-- Since we backported the UDF below from version 11.3, the definition is the same
-#include "11.3-1.sql"
-
--- a/src/backend/distributed/utils/array_type.c
+++ b/src/backend/distributed/utils/array_type.c
@ -140,34 +140,3 @@ TextArrayTypeToIntegerList(ArrayType *arrayObject)

 	return list;
 }
-
-
-/*
- * IntArrayToDatum
- *
- * Convert an integer array to the datum int array format
- * (currently used for nodes_involved in pg_dist_background_task)
- *
- * Returns the array in the form of a Datum, or PointerGetDatum(NULL)
- * if the int_array is empty.
- */
-Datum
-IntArrayToDatum(uint32 int_array_size, int int_array[])
-{
-	if (int_array_size == 0)
-	{
-		return PointerGetDatum(NULL);
-	}
-
-	ArrayBuildState *astate = NULL;
-	for (int i = 0; i < int_array_size; i++)
-	{
-		Datum dvalue = Int32GetDatum(int_array[i]);
-		bool disnull = false;
-		Oid element_type = INT4OID;
-		astate = accumArrayResult(astate, dvalue, disnull, element_type,
-								  CurrentMemoryContext);
-	}
-
-	return makeArrayResult(astate, CurrentMemoryContext);
-}
--- a/src/backend/distributed/utils/background_jobs.c
+++ b/src/backend/distributed/utils/background_jobs.c
@ -63,7 +63,6 @@
 #include "distributed/metadata_cache.h"
 #include "distributed/metadata_utility.h"
 #include "distributed/shard_cleaner.h"
-#include "distributed/shard_rebalancer.h"
 #include "distributed/resource_lock.h"

 /* Table-of-contents constants for our dynamic shared memory segment. */
@ -116,17 +115,12 @@ static bool MonitorGotTerminationOrCancellationRequest();
 static void QueueMonitorSigTermHandler(SIGNAL_ARGS);
 static void QueueMonitorSigIntHandler(SIGNAL_ARGS);
 static void QueueMonitorSigHupHandler(SIGNAL_ARGS);
-static void DecrementParallelTaskCountForNodesInvolved(BackgroundTask *task);

 /* flags set by signal handlers */
 static volatile sig_atomic_t GotSigterm = false;
 static volatile sig_atomic_t GotSigint = false;
 static volatile sig_atomic_t GotSighup = false;

-/* keeping track of parallel background tasks per node */
-HTAB *ParallelTasksPerNode = NULL;
-int MaxBackgroundTaskExecutorsPerNode = 1;
-
 PG_FUNCTION_INFO_V1(citus_job_cancel);
 PG_FUNCTION_INFO_V1(citus_job_wait);
 PG_FUNCTION_INFO_V1(citus_task_wait);
@ -217,7 +211,7 @@ citus_job_wait(PG_FUNCTION_ARGS)
 *   assume any terminal state as its desired status. The function returns if the
 *   desired_state was reached.
 *
- * The current implementation is a polling implementation with an interval of 0.1 seconds.
+ * The current implementation is a polling implementation with an interval of 1 second.
 * Ideally we would have some synchronization between the background tasks queue monitor
 * and any backend calling this function to receive a signal when the task changes state.
 */
@ -863,7 +857,6 @@ TaskEnded(TaskExecutionContext *taskExecutionContext)
 	UpdateBackgroundTask(task);
 	UpdateDependingTasks(task);
 	UpdateBackgroundJob(task->jobid);
-	DecrementParallelTaskCountForNodesInvolved(task);

 	/* we are sure that at least one task did not block on current iteration */
 	queueMonitorExecutionContext->allTasksWouldBlock = false;
@ -875,77 +868,6 @@ TaskEnded(TaskExecutionContext *taskExecutionContext)
 }


-/*
- * IncrementParallelTaskCountForNodesInvolved
- * Checks whether we have reached the limit of parallel tasks per node
- * per each of the nodes involved with the task
- * If at least one limit is reached, it returns false.
- * If limits aren't reached, it increments the parallel task count
- * for each of the nodes involved with the task, and returns true.
- */
-bool
-IncrementParallelTaskCountForNodesInvolved(BackgroundTask *task)
-{
-	if (task->nodesInvolved)
-	{
-		int node;
-
-		/* first check whether we have reached the limit for any of the nodes */
-		foreach_int(node, task->nodesInvolved)
-		{
-			bool found;
-			ParallelTasksPerNodeEntry *hashEntry = hash_search(
-				ParallelTasksPerNode, &(node), HASH_ENTER, &found);
-			if (!found)
-			{
-				hashEntry->counter = 0;
-			}
-			else if (hashEntry->counter >= MaxBackgroundTaskExecutorsPerNode)
-			{
-				/* at least one node's limit is reached */
-				return false;
-			}
-		}
-
-		/* then, increment the parallel task count per each node */
-		foreach_int(node, task->nodesInvolved)
-		{
-			ParallelTasksPerNodeEntry *hashEntry = hash_search(
-				ParallelTasksPerNode, &(node), HASH_FIND, NULL);
-			Assert(hashEntry);
-			hashEntry->counter += 1;
-		}
-	}
-
-	return true;
-}
-
-
-/*
- * DecrementParallelTaskCountForNodesInvolved
- * Decrements the parallel task count for each of the nodes involved
- * with the task.
- * We call this function after the task has gone through Running state
- * and then has ended.
- */
-static void
-DecrementParallelTaskCountForNodesInvolved(BackgroundTask *task)
-{
-	if (task->nodesInvolved)
-	{
-		int node;
-		foreach_int(node, task->nodesInvolved)
-		{
-			ParallelTasksPerNodeEntry *hashEntry = hash_search(ParallelTasksPerNode,
-															   &(node),
-															   HASH_FIND, NULL);
-
-			hashEntry->counter -= 1;
-		}
-	}
-}
-
-
 /*
 * QueueMonitorSigHupHandler handles SIGHUP to update monitor related config params.
 */
@ -1101,7 +1023,7 @@ CitusBackgroundTaskQueueMonitorMain(Datum arg)
 	/* handle SIGINT to properly cancel active task executors */
 	pqsignal(SIGINT, QueueMonitorSigIntHandler);

-	/* handle SIGHUP to update MaxBackgroundTaskExecutors and MaxBackgroundTaskExecutorsPerNode */
+	/* handle SIGHUP to update MaxBackgroundTaskExecutors */
 	pqsignal(SIGHUP, QueueMonitorSigHupHandler);

 	/* ready to handle signals */
@ -1245,15 +1167,10 @@ CitusBackgroundTaskQueueMonitorMain(Datum arg)
 		{
 			GotSighup = false;

-			/* update max_background_task_executors and max_background_task_executors_per_node if changed */
+			/* update max_background_task_executors if changed */
 			ProcessConfigFile(PGC_SIGHUP);
 		}

-		if (ParallelTasksPerNode == NULL)
-		{
-			ParallelTasksPerNode = CreateSimpleHash(int32, ParallelTasksPerNodeEntry);
-		}
-
 		/* assign runnable tasks, if any, to new task executors in a transaction if we do not have SIGTERM or SIGINT */
 		if (!MonitorGotTerminationOrCancellationRequest())
 		{
--- a/src/include/distributed/background_jobs.h
+++ b/src/include/distributed/background_jobs.h
@ -85,21 +85,6 @@ typedef struct TaskExecutionContext
 } TaskExecutionContext;


-/*
- * ParallelTasksPerNodeEntry is the struct used
- * to track the number of concurrent background tasks that
- * involve a particular node (the key to the entry)
- */
-typedef struct ParallelTasksPerNodeEntry
-{
-	/* Used as hash key. */
-	int32 node_id;
-
-	/* number of concurrent background tasks that involve node node_id */
-	uint32 counter;
-} ParallelTasksPerNodeEntry;
-
-
 extern BackgroundWorkerHandle * StartCitusBackgroundTaskQueueMonitor(Oid database,
 																	 Oid extensionOwner);
 extern void CitusBackgroundTaskQueueMonitorMain(Datum arg);
@ -110,6 +95,5 @@ extern Datum citus_job_wait(PG_FUNCTION_ARGS);
 extern Datum citus_task_wait(PG_FUNCTION_ARGS);
 extern void citus_job_wait_internal(int64 jobid, BackgroundJobStatus *desiredStatus);
 extern void citus_task_wait_internal(int64 taskid, BackgroundTaskStatus *desiredStatus);
-extern bool IncrementParallelTaskCountForNodesInvolved(BackgroundTask *task);

 #endif /*CITUS_BACKGROUND_JOBS_H */
--- a/src/include/distributed/metadata_utility.h
+++ b/src/include/distributed/metadata_utility.h
@ -252,7 +252,6 @@ typedef struct BackgroundTask
 	int32 *retry_count;
 	TimestampTz *not_before;
 	char *message;
-	List *nodesInvolved;

 	/* extra space to store values for nullable value types above */
 	struct
@ -389,9 +388,7 @@ extern bool HasNonTerminalJobOfType(const char *jobType, int64 *jobIdOut);
 extern int64 CreateBackgroundJob(const char *jobType, const char *description);
 extern BackgroundTask * ScheduleBackgroundTask(int64 jobId, Oid owner, char *command,
 											   int dependingTaskCount,
-											   int64 dependingTaskIds[],
-											   int nodesInvolvedCount,
-											   int32 nodesInvolved[]);
+											   int64 dependingTaskIds[]);
 extern BackgroundTask * GetRunnableBackgroundTask(void);
 extern void ResetRunningBackgroundTasks(void);
 extern BackgroundJob * GetBackgroundJobByJobId(int64 jobId);
--- a/src/include/distributed/pg_dist_background_task.h
+++ b/src/include/distributed/pg_dist_background_task.h
@ -15,7 +15,7 @@
 *      compiler constants for pg_dist_background_task
 * ----------------
 */
-#define Natts_pg_dist_background_task 10
+#define Natts_pg_dist_background_task 9
 #define Anum_pg_dist_background_task_job_id 1
 #define Anum_pg_dist_background_task_task_id 2
 #define Anum_pg_dist_background_task_owner 3
@ -25,6 +25,5 @@
 #define Anum_pg_dist_background_task_retry_count 7
 #define Anum_pg_dist_background_task_not_before 8
 #define Anum_pg_dist_background_task_message 9
-#define Anum_pg_dist_background_task_nodes_involved 10

 #endif /* CITUS_PG_DIST_BACKGROUND_TASK_H */
--- a/src/include/distributed/shard_rebalancer.h
+++ b/src/include/distributed/shard_rebalancer.h
@ -190,7 +190,6 @@ extern char *VariablesToBePassedToNewConnections;
 extern int MaxRebalancerLoggedIgnoredMoves;
 extern bool RunningUnderIsolationTest;
 extern bool PropagateSessionSettingsForLoopbackConnection;
-extern int MaxBackgroundTaskExecutorsPerNode;

 /* External function declarations */
 extern Datum shard_placement_rebalance_array(PG_FUNCTION_ARGS);
--- a/src/include/distributed/utils/array_type.h
+++ b/src/include/distributed/utils/array_type.h
@ -22,6 +22,5 @@ extern ArrayType * DatumArrayToArrayType(Datum *datumArray, int datumCount,
 										 Oid datumTypeId);
 extern List * IntegerArrayTypeToList(ArrayType *arrayObject);
 extern List * TextArrayTypeToIntegerList(ArrayType *arrayObject);
-extern Datum IntArrayToDatum(uint32 int_array_size, int int_array[]);

 #endif   /* CITUS_ARRAY_TYPE_H */
--- a/src/test/cdc/t/016_cdc_wal2json.pl
+++ b/src/test/cdc/t/016_cdc_wal2json.pl
@ -1,51 +0,0 @@
-# Schema change CDC test for Citus
-use strict;
-use warnings;
-
-use Test::More;
-
-use lib './t';
-use cdctestlib;
-
-use threads;
-
-# Initialize co-ordinator node
-my $select_stmt = qq(SELECT * FROM data_100008 ORDER BY id;);
-my $result = 0;
-
-### Create the citus cluster with coordinator and two worker nodes
-our ($node_coordinator, @workers) = create_citus_cluster(1,"localhost",57636);
-
-print("coordinator port: " . $node_coordinator->port() . "\n");
-print("worker0 port:" . $workers[0]->port() . "\n");
-
-my $initial_schema = "
-        CREATE TABLE data_100008(
-                id  integer,
-                data text,
-                PRIMARY KEY (data));";
-
-$node_coordinator->safe_psql('postgres',$initial_schema);
-$node_coordinator->safe_psql('postgres','ALTER TABLE data_100008 REPLICA IDENTITY FULL;');
-$node_coordinator->safe_psql('postgres',"SELECT pg_catalog.pg_create_logical_replication_slot('cdc_replication_slot','wal2json');");
-
-#insert data into the data_100008 table in the coordinator node before distributing the table.
-$node_coordinator->safe_psql('postgres',"
-  	INSERT INTO data_100008
-  SELECT i, 'my test data ' || i
-  FROM generate_series(-1,1)i;");
-
-my $output = $node_coordinator->safe_psql('postgres',"SELECT * FROM pg_logical_slot_get_changes('cdc_replication_slot', NULL, NULL);");
-print($output);
-
-my $change_string_expected = '[0,"my test data 0"]';
-if ($output =~ /$change_string_expected/) {
-  $result = 1;
-} else {
-  $result = 0;
-}
-
-is($result, 1, 'CDC create_distributed_table - wal2json test');
-$node_coordinator->safe_psql('postgres',"SELECT pg_drop_replication_slot('cdc_replication_slot');");
-
-done_testing();
--- a/src/test/regress/after_citus_upgrade_coord_schedule
+++ b/src/test/regress/after_citus_upgrade_coord_schedule
@ -1,7 +1,6 @@
 # this schedule is to be run only on coordinators

 test: upgrade_citus_finish_citus_upgrade
-test: upgrade_pg_dist_cleanup_after
 test: upgrade_basic_after
 test: upgrade_partition_constraints_after
 test: upgrade_pg_dist_object_test_after
--- a/src/test/regress/before_citus_upgrade_coord_schedule
+++ b/src/test/regress/before_citus_upgrade_coord_schedule
@ -4,5 +4,4 @@ test: upgrade_basic_before
 test: upgrade_partition_constraints_before
 test: upgrade_pg_dist_object_test_before
 test: upgrade_columnar_metapage_before
-test: upgrade_pg_dist_cleanup_before
 test: upgrade_post_11_before
--- a/src/test/regress/citus_tests/config.py
+++ b/src/test/regress/citus_tests/config.py
@ -110,7 +110,7 @@ class CitusBaseClusterConfig(object, metaclass=NewInitCaller):
            "max_connections": 1200,
        }
        self.new_settings = {}
-        self.add_coordinator_to_metadata = True
+        self.add_coordinator_to_metadata = False
        self.env_variables = {}
        self.skip_tests = []

@ -166,6 +166,7 @@ class CitusDefaultClusterConfig(CitusBaseClusterConfig):
            "citus.use_citus_managed_tables": True,
        }
        self.settings.update(new_settings)
+        self.add_coordinator_to_metadata = True
        self.skip_tests = [
            # Alter Table statement cannot be run from an arbitrary node so this test will fail
            "arbitrary_configs_alter_table_add_constraint_without_name_create",
@ -379,3 +380,4 @@ class PGUpgradeConfig(CitusBaseClusterConfig):
        self.old_datadir = self.temp_dir + "/oldData"
        self.new_datadir = self.temp_dir + "/newData"
        self.user = SUPER_USER_NAME
+        self.add_coordinator_to_metadata = True
--- a/src/test/regress/expected/background_rebalance_parallel.out
+++ b/src/test/regress/expected/background_rebalance_parallel.out
@ -1,22 +1,12 @@
--
-- BACKGROUND_REBALANCE_PARALLEL
--
-- Test to check if the background tasks scheduled by the background rebalancer
-- have the correct dependencies
--
-- Test to verify that we do not allow parallel rebalancer moves involving a
-- particular node (either as source or target) more than
-- citus.max_background_task_executors_per_node, and that we can change the GUC on
-- the fly, and that will affect the ongoing balance as it should
--
-- Test to verify that there's a hard dependency when a specific node is first being
-- used as a source for a move, and then later as a target.
--
+/*
+  Test to check if the background tasks scheduled by the background rebalancer
+  has the correct dependencies.
+*/
 CREATE SCHEMA background_rebalance_parallel;
 SET search_path TO background_rebalance_parallel;
 SET citus.next_shard_id TO 85674000;
 SET citus.shard_replication_factor TO 1;
-SET client_min_messages TO ERROR;
+SET client_min_messages TO WARNING;
 ALTER SEQUENCE pg_dist_background_job_job_id_seq RESTART 17777;
 ALTER SEQUENCE pg_dist_background_task_task_id_seq RESTART 1000;
 ALTER SEQUENCE pg_catalog.pg_dist_colocationid_seq RESTART 50050;
@ -55,7 +45,7 @@ SELECT pg_reload_conf();
 t
 (1 row)

-- Colocation group 1: create two tables table1_colg1, table2_colg1 and in a colocation group
+/* Colocation group 1: create two tables table1_colg1, table2_colg1 and in a colocation group  */
 CREATE TABLE table1_colg1 (a int PRIMARY KEY);
 SELECT create_distributed_table('table1_colg1', 'a', shard_count => 4 , colocate_with => 'none');
 create_distributed_table
@ -70,7 +60,7 @@ SELECT create_distributed_table('table2_colg1', 'b', colocate_with => 'table1_co

 (1 row)

-- Colocation group 2: create two tables table1_colg2, table2_colg2 and in a colocation group
+/* Colocation group 2: create two tables table1_colg2, table2_colg2 and in a colocation group  */
 CREATE TABLE table1_colg2 (a int PRIMARY KEY);
 SELECT create_distributed_table('table1_colg2 ', 'a', shard_count => 4, colocate_with => 'none');
 create_distributed_table
@ -85,7 +75,7 @@ SELECT create_distributed_table('table2_colg2', 'b', colocate_with => 'table1_co

 (1 row)

-- Colocation group 3: create two tables table1_colg3, table2_colg3 and in a colocation group
+/* Colocation group 3: create two tables table1_colg3, table2_colg3 and in a colocation group  */
 CREATE TABLE table1_colg3 (a int PRIMARY KEY);
 SELECT create_distributed_table('table1_colg3 ', 'a', shard_count => 4, colocate_with => 'none');
 create_distributed_table
@ -100,7 +90,7 @@ SELECT create_distributed_table('table2_colg3', 'b', colocate_with => 'table1_co

 (1 row)

-- Add two new nodes so that we can rebalance
+/* Add two new node so that we can rebalance */
 SELECT 1 FROM citus_add_node('localhost', :worker_3_port);
 ?column?
 ---------------------------------------------------------------------
@ -142,11 +132,10 @@ SELECT citus_rebalance_wait();

 (1 row)

-- PART 1
-- Test to check if the background tasks scheduled by the background rebalancer
-- have the correct dependencies
-- Check that a move is dependent on
-- any other move scheduled earlier in its colocation group.
+/*Check that a move is dependent on
+	1. any other move scheduled earlier in its colocation group.
+	2. any other move scheduled earlier whose source node or target
+	   node overlaps with the current moves nodes. */
 SELECT S.shardid, P.colocationid
 FROM pg_dist_shard S, pg_dist_partition P
 WHERE S.logicalrelid = P.logicalrelid ORDER BY S.shardid ASC;
@ -186,12 +175,16 @@ FROM pg_dist_background_task_depend D  WHERE job_id = 17777 ORDER BY D.task_id,
 task_id |                               command                               | depends_on |                               command
 ---------------------------------------------------------------------
    1001 | SELECT pg_catalog.citus_move_shard_placement(85674000,50,53,'auto') |       1000 | SELECT pg_catalog.citus_move_shard_placement(85674001,51,52,'auto')
+    1002 | SELECT pg_catalog.citus_move_shard_placement(85674009,51,52,'auto') |       1000 | SELECT pg_catalog.citus_move_shard_placement(85674001,51,52,'auto')
+    1003 | SELECT pg_catalog.citus_move_shard_placement(85674008,50,53,'auto') |       1001 | SELECT pg_catalog.citus_move_shard_placement(85674000,50,53,'auto')
    1003 | SELECT pg_catalog.citus_move_shard_placement(85674008,50,53,'auto') |       1002 | SELECT pg_catalog.citus_move_shard_placement(85674009,51,52,'auto')
+    1004 | SELECT pg_catalog.citus_move_shard_placement(85674017,51,52,'auto') |       1002 | SELECT pg_catalog.citus_move_shard_placement(85674009,51,52,'auto')
+    1005 | SELECT pg_catalog.citus_move_shard_placement(85674016,50,53,'auto') |       1003 | SELECT pg_catalog.citus_move_shard_placement(85674008,50,53,'auto')
    1005 | SELECT pg_catalog.citus_move_shard_placement(85674016,50,53,'auto') |       1004 | SELECT pg_catalog.citus_move_shard_placement(85674017,51,52,'auto')
-(3 rows)
+(7 rows)

-- Check that if there is a reference table that needs to be synched to a node,
-- any move without a dependency must depend on the move task for reference table.
+/* Check that if there is a reference table that needs to be synched to a node,
+   any move without a dependency must depend on the move task for reference table. */
 SELECT 1 FROM citus_drain_node('localhost',:worker_4_port);
 ?column?
 ---------------------------------------------------------------------
@ -210,8 +203,8 @@ SELECT 1 FROM citus_disable_node('localhost', :worker_4_port, synchronous:=true)
        1
 (1 row)

-- Drain worker_3 so that we can move only one colocation group to worker_3
-- to create an unbalance that would cause parallel rebalancing.
+/* Drain worker_3 so that we can move only one colocation group to worker_3
+   to create an unbalance that would cause parallel rebalancing. */
 SELECT 1 FROM citus_drain_node('localhost',:worker_3_port);
 ?column?
 ---------------------------------------------------------------------
@ -232,7 +225,7 @@ SELECT create_reference_table('ref_table');

 (1 row)

-- Move all the shards of Colocation group 3 to worker_3.
+/* Move all the shards of Colocation group 3 to worker_3.*/
 SELECT
 master_move_shard_placement(shardid, 'localhost', nodeport, 'localhost', :worker_3_port, 'block_writes')
 FROM
@ -250,7 +243,7 @@ ORDER BY
 (4 rows)

 CALL citus_cleanup_orphaned_resources();
-- Activate and new  nodes so that we can rebalance.
+/* Activate and new  nodes so that we can rebalance. */
 SELECT 1 FROM citus_activate_node('localhost', :worker_4_port);
 ?column?
 ---------------------------------------------------------------------
@ -330,34 +323,18 @@ FROM pg_dist_background_task_depend D  WHERE job_id = 17778 ORDER BY D.task_id,
    1008 | SELECT pg_catalog.citus_move_shard_placement(85674003,51,54,'auto') |       1006 | SELECT pg_catalog.replicate_reference_tables('auto')
    1009 | SELECT pg_catalog.citus_move_shard_placement(85674000,50,55,'auto') |       1008 | SELECT pg_catalog.citus_move_shard_placement(85674003,51,54,'auto')
    1010 | SELECT pg_catalog.citus_move_shard_placement(85674017,52,53,'auto') |       1007 | SELECT pg_catalog.citus_move_shard_placement(85674016,52,53,'auto')
-    1011 | SELECT pg_catalog.citus_move_shard_placement(85674008,51,54,'auto') |       1006 | SELECT pg_catalog.replicate_reference_tables('auto')
+    1011 | SELECT pg_catalog.citus_move_shard_placement(85674008,51,54,'auto') |       1008 | SELECT pg_catalog.citus_move_shard_placement(85674003,51,54,'auto')
    1012 | SELECT pg_catalog.citus_move_shard_placement(85674001,50,55,'auto') |       1009 | SELECT pg_catalog.citus_move_shard_placement(85674000,50,55,'auto')
 (6 rows)

-- PART 2
-- Test to verify that we do not allow parallel rebalancer moves involving a
-- particular node (either as source or target)
-- more than citus.max_background_task_executors_per_node
-- and that we can change the GUC on the fly
-- citus_task_wait calls are used to ensure consistent pg_dist_background_task query
-- output i.e. to avoid flakiness
-- First let's restart the scenario
 DROP SCHEMA background_rebalance_parallel CASCADE;
 TRUNCATE pg_dist_background_job CASCADE;
-TRUNCATE pg_dist_background_task CASCADE;
-TRUNCATE pg_dist_background_task_depend;
 SELECT public.wait_for_resource_cleanup();
 wait_for_resource_cleanup
 ---------------------------------------------------------------------

 (1 row)

-select citus_remove_node('localhost', :worker_2_port);
- citus_remove_node
---------------------------------------------------------------------
-
-(1 row)
-
 select citus_remove_node('localhost', :worker_3_port);
 citus_remove_node
 ---------------------------------------------------------------------
@ -382,474 +359,6 @@ select citus_remove_node('localhost', :worker_6_port);

 (1 row)

-CREATE SCHEMA background_rebalance_parallel;
-SET search_path TO background_rebalance_parallel;
-- Create 8 tables in 4 colocation groups, and populate them
-CREATE TABLE table1_colg1 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg1', 'a', shard_count => 3, colocate_with => 'none');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-INSERT INTO table1_colg1 SELECT i FROM generate_series(0, 100)i;
-CREATE TABLE table2_colg1 (b int PRIMARY KEY);
-SELECT create_distributed_table('table2_colg1', 'b', colocate_with => 'table1_colg1');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-INSERT INTO table2_colg1 SELECT i FROM generate_series(0, 100)i;
-CREATE TABLE table1_colg2 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg2', 'a', shard_count => 3, colocate_with => 'none');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-INSERT INTO table1_colg2 SELECT i FROM generate_series(0, 100)i;
-CREATE TABLE table2_colg2 (b int PRIMARY KEY);
-SELECT create_distributed_table('table2_colg2', 'b', colocate_with => 'table1_colg2');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-INSERT INTO table2_colg2 SELECT i FROM generate_series(0, 100)i;
-CREATE TABLE table1_colg3 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg3', 'a', shard_count => 3, colocate_with => 'none');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-INSERT INTO table1_colg3 SELECT i FROM generate_series(0, 100)i;
-CREATE TABLE  table2_colg3 (b int primary key);
-SELECT create_distributed_table('table2_colg3', 'b', colocate_with => 'table1_colg3');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-INSERT INTO table2_colg3 SELECT i FROM generate_series(0, 100)i;
-CREATE TABLE table1_colg4 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg4', 'a', shard_count => 3, colocate_with => 'none');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-INSERT INTO table1_colg4 SELECT i FROM generate_series(0, 100)i;
-CREATE TABLE table2_colg4 (b int PRIMARY KEY);
-SELECT create_distributed_table('table2_colg4', 'b', colocate_with => 'table1_colg4');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-INSERT INTO table2_colg4 SELECT i FROM generate_series(0, 100)i;
-- Add nodes so that we can rebalance
-SELECT citus_add_node('localhost', :worker_2_port);
- citus_add_node
---------------------------------------------------------------------
-             56
-(1 row)
-
-SELECT citus_add_node('localhost', :worker_3_port);
- citus_add_node
---------------------------------------------------------------------
-             57
-(1 row)
-
-SELECT citus_rebalance_start AS job_id from citus_rebalance_start() \gset
-- see dependent tasks to understand which tasks remain runnable because of
-- citus.max_background_task_executors_per_node
-- and which tasks are actually blocked from colocation group dependencies
-SELECT D.task_id,
-       (SELECT T.command FROM pg_dist_background_task T WHERE T.task_id = D.task_id),
-       D.depends_on,
-       (SELECT T.command FROM pg_dist_background_task T WHERE T.task_id = D.depends_on)
-FROM pg_dist_background_task_depend D  WHERE job_id in (:job_id) ORDER BY D.task_id, D.depends_on ASC;
- task_id |                               command                               | depends_on |                               command
---------------------------------------------------------------------
-    1014 | SELECT pg_catalog.citus_move_shard_placement(85674026,50,57,'auto') |       1013 | SELECT pg_catalog.citus_move_shard_placement(85674025,50,56,'auto')
-    1016 | SELECT pg_catalog.citus_move_shard_placement(85674032,50,57,'auto') |       1015 | SELECT pg_catalog.citus_move_shard_placement(85674031,50,56,'auto')
-    1018 | SELECT pg_catalog.citus_move_shard_placement(85674038,50,57,'auto') |       1017 | SELECT pg_catalog.citus_move_shard_placement(85674037,50,56,'auto')
-    1020 | SELECT pg_catalog.citus_move_shard_placement(85674044,50,57,'auto') |       1019 | SELECT pg_catalog.citus_move_shard_placement(85674043,50,56,'auto')
-(4 rows)
-
-- default citus.max_background_task_executors_per_node is 1
-- show that first exactly one task per node is running
-- among the tasks that are not blocked
-SELECT citus_task_wait(1013, desired_status => 'running');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT job_id, task_id, status, nodes_involved
-FROM pg_dist_background_task WHERE job_id in (:job_id) ORDER BY task_id;
- job_id | task_id |  status  | nodes_involved
---------------------------------------------------------------------
-  17779 |    1013 | running  | {50,56}
-  17779 |    1014 | blocked  | {50,57}
-  17779 |    1015 | runnable | {50,56}
-  17779 |    1016 | blocked  | {50,57}
-  17779 |    1017 | runnable | {50,56}
-  17779 |    1018 | blocked  | {50,57}
-  17779 |    1019 | runnable | {50,56}
-  17779 |    1020 | blocked  | {50,57}
-(8 rows)
-
-- increase citus.max_background_task_executors_per_node
-ALTER SYSTEM SET citus.max_background_task_executors_per_node = 2;
-SELECT pg_reload_conf();
- pg_reload_conf
---------------------------------------------------------------------
- t
-(1 row)
-
-SELECT citus_task_wait(1015, desired_status => 'running');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_task_wait(1013, desired_status => 'done');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-- show that at most 2 tasks per node are running
-- among the tasks that are not blocked
-SELECT job_id, task_id, status, nodes_involved
-FROM pg_dist_background_task WHERE job_id in (:job_id) ORDER BY task_id;
- job_id | task_id |  status  | nodes_involved
---------------------------------------------------------------------
-  17779 |    1013 | done     | {50,56}
-  17779 |    1014 | running  | {50,57}
-  17779 |    1015 | running  | {50,56}
-  17779 |    1016 | blocked  | {50,57}
-  17779 |    1017 | runnable | {50,56}
-  17779 |    1018 | blocked  | {50,57}
-  17779 |    1019 | runnable | {50,56}
-  17779 |    1020 | blocked  | {50,57}
-(8 rows)
-
-- decrease to default (1)
-ALTER SYSTEM RESET citus.max_background_task_executors_per_node;
-SELECT pg_reload_conf();
- pg_reload_conf
---------------------------------------------------------------------
- t
-(1 row)
-
-SELECT citus_task_wait(1015, desired_status => 'done');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_task_wait(1014, desired_status => 'done');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_task_wait(1016, desired_status => 'running');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-- show that exactly one task per node is running
-- among the tasks that are not blocked
-SELECT job_id, task_id, status, nodes_involved
-FROM pg_dist_background_task WHERE job_id in (:job_id) ORDER BY task_id;
- job_id | task_id |  status  | nodes_involved
---------------------------------------------------------------------
-  17779 |    1013 | done     | {50,56}
-  17779 |    1014 | done     | {50,57}
-  17779 |    1015 | done     | {50,56}
-  17779 |    1016 | running  | {50,57}
-  17779 |    1017 | runnable | {50,56}
-  17779 |    1018 | blocked  | {50,57}
-  17779 |    1019 | runnable | {50,56}
-  17779 |    1020 | blocked  | {50,57}
-(8 rows)
-
-SELECT citus_rebalance_stop();
- citus_rebalance_stop
---------------------------------------------------------------------
-
-(1 row)
-
-- PART 3
-- Test to verify that there's a hard dependency when A specific node is first being used as a
-- source for a move, and then later as a target.
-- First let's restart the scenario
-DROP SCHEMA background_rebalance_parallel CASCADE;
-TRUNCATE pg_dist_background_job CASCADE;
-TRUNCATE pg_dist_background_task CASCADE;
-TRUNCATE pg_dist_background_task_depend;
-SELECT public.wait_for_resource_cleanup();
- wait_for_resource_cleanup
---------------------------------------------------------------------
-
-(1 row)
-
-select citus_remove_node('localhost', :worker_1_port);
- citus_remove_node
---------------------------------------------------------------------
-
-(1 row)
-
-select citus_remove_node('localhost', :worker_2_port);
- citus_remove_node
---------------------------------------------------------------------
-
-(1 row)
-
-select citus_remove_node('localhost', :worker_3_port);
- citus_remove_node
---------------------------------------------------------------------
-
-(1 row)
-
-CREATE SCHEMA background_rebalance_parallel;
-SET search_path TO background_rebalance_parallel;
-SET citus.next_shard_id TO 85674051;
-ALTER SEQUENCE pg_catalog.pg_dist_node_nodeid_seq RESTART 61;
-- add the first node
-- nodeid here is 61
-select citus_add_node('localhost', :worker_1_port);
- citus_add_node
---------------------------------------------------------------------
-             61
-(1 row)
-
-- create, populate and distribute 6 tables, each with 1 shard, none colocated with each other
-CREATE TABLE table1_colg1 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg1', 'a', shard_count => 1, colocate_with => 'none');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-INSERT INTO table1_colg1 SELECT i FROM generate_series(0, 100)i;
-CREATE TABLE table1_colg2 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg2', 'a', shard_count => 1, colocate_with => 'none');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-INSERT INTO table1_colg2 SELECT i FROM generate_series(0, 100)i;
-CREATE TABLE table1_colg3 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg3', 'a', shard_count => 1, colocate_with => 'none');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-INSERT INTO table1_colg3 SELECT i FROM generate_series(0, 100)i;
-CREATE TABLE table1_colg4 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg4', 'a', shard_count => 1, colocate_with => 'none');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-INSERT INTO table1_colg4 SELECT i FROM generate_series(0, 100)i;
-CREATE TABLE table1_colg5 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg5', 'a', shard_count => 1, colocate_with => 'none');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-INSERT INTO table1_colg5 SELECT i FROM generate_series(0, 100)i;
-CREATE TABLE table1_colg6 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg6', 'a', shard_count => 1, colocate_with => 'none');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-INSERT INTO table1_colg6 SELECT i FROM generate_series(0, 100)i;
-- add two other nodes
-- nodeid here is 62
-select citus_add_node('localhost', :worker_2_port);
- citus_add_node
---------------------------------------------------------------------
-             62
-(1 row)
-
-- nodeid here is 63
-select citus_add_node('localhost', :worker_3_port);
- citus_add_node
---------------------------------------------------------------------
-             63
-(1 row)
-
-CREATE OR REPLACE FUNCTION shard_placement_rebalance_array(
-    worker_node_list json[],
-    shard_placement_list json[],
-    threshold float4 DEFAULT 0,
-    max_shard_moves int DEFAULT 1000000,
-    drain_only bool DEFAULT false,
-    improvement_threshold float4 DEFAULT 0.5
-)
-RETURNS json[]
-AS 'citus'
-LANGUAGE C STRICT VOLATILE;
-- we are simulating the following from shard_rebalancer_unit.sql
-- the following steps are all according to this scenario
-- where the third move should be dependent of the first two
-- because the third move's target is the source of the first two
-SELECT unnest(shard_placement_rebalance_array(
-    ARRAY['{"node_name": "hostname1", "disallowed_shards": "1,2,3,5,6"}',
-          '{"node_name": "hostname2", "disallowed_shards": "4"}',
-          '{"node_name": "hostname3", "disallowed_shards": "4"}'
-        ]::json[],
-    ARRAY['{"shardid":1, "nodename":"hostname1"}',
-          '{"shardid":2, "nodename":"hostname1"}',
-          '{"shardid":3, "nodename":"hostname2"}',
-          '{"shardid":4, "nodename":"hostname2"}',
-          '{"shardid":5, "nodename":"hostname3"}',
-          '{"shardid":6, "nodename":"hostname3"}'
-        ]::json[]
-));
-                                                       unnest
---------------------------------------------------------------------
- {"updatetype":1,"shardid":1,"sourcename":"hostname1","sourceport":5432,"targetname":"hostname2","targetport":5432}
- {"updatetype":1,"shardid":2,"sourcename":"hostname1","sourceport":5432,"targetname":"hostname3","targetport":5432}
- {"updatetype":1,"shardid":4,"sourcename":"hostname2","sourceport":5432,"targetname":"hostname1","targetport":5432}
-(3 rows)
-
-- manually balance the cluster such that we have
-- a balanced cluster like above with 1,2,3,4,5,6 and hostname1/2/3
-- shardid 85674051 (1) nodeid 61 (hostname1)
-- shardid 85674052 (2) nodeid 61 (hostname1)
-- shardid 85674053 (3) nodeid 62 (hostname2)
-- shardid 85674054 (4) nodeid 62 (hostname2)
-- shardid 85674055 (5) nodeid 63 (hostname3)
-- shardid 85674056 (6) nodeid 63 (hostname3)
-SELECT pg_catalog.citus_move_shard_placement(85674053,61,62,'auto');
- citus_move_shard_placement
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT pg_catalog.citus_move_shard_placement(85674054,61,62,'auto');
- citus_move_shard_placement
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT pg_catalog.citus_move_shard_placement(85674055,61,63,'auto');
- citus_move_shard_placement
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT pg_catalog.citus_move_shard_placement(85674056,61,63,'auto');
- citus_move_shard_placement
---------------------------------------------------------------------
-
-(1 row)
-
-- now create another rebalance strategy in order to simulate moves
-- which use as target a node that has been previously used as source
-CREATE OR REPLACE FUNCTION test_shard_allowed_on_node(shardid bigint, nodeid int)
-    RETURNS boolean AS
-$$
-    -- analogous to '{"node_name": "hostname1", "disallowed_shards": "1,2,3,5,6"}'
-    select case when (shardid != 85674054 and nodeid = 61)
-        then false
-    -- analogous to '{"node_name": "hostname2", "disallowed_shards": "4"}'
-    --          AND '{"node_name": "hostname2", "disallowed_shards": "4"}'
-    when (shardid = 85674054 and nodeid != 61)
-        then false
-    else true
-    end;
-$$ LANGUAGE sql;
-- insert the new test rebalance strategy
-INSERT INTO
-    pg_catalog.pg_dist_rebalance_strategy(
-        name,
-        default_strategy,
-        shard_cost_function,
-        node_capacity_function,
-        shard_allowed_on_node_function,
-        default_threshold,
-        minimum_threshold,
-        improvement_threshold
-    ) VALUES (
-        'test_source_then_target',
-        false,
-        'citus_shard_cost_1',
-        'citus_node_capacity_1',
-        'background_rebalance_parallel.test_shard_allowed_on_node',
-        0,
-        0,
-        0
-    );
-SELECT * FROM get_rebalance_table_shards_plan(rebalance_strategy := 'test_source_then_target');
-  table_name  | shardid  | shard_size | sourcename | sourceport | targetname | targetport
---------------------------------------------------------------------
- table1_colg1 | 85674051 |          0 | localhost  |      57637 | localhost  |      57638
- table1_colg2 | 85674052 |          0 | localhost  |      57637 | localhost  |      57639
- table1_colg4 | 85674054 |          0 | localhost  |      57638 | localhost  |      57637
-(3 rows)
-
-SELECT citus_rebalance_start AS job_id from citus_rebalance_start(rebalance_strategy := 'test_source_then_target') \gset
-- check that the third move is blocked and depends on the first two
-SELECT job_id, task_id, status, nodes_involved
-FROM pg_dist_background_task WHERE job_id in (:job_id) ORDER BY task_id;
- job_id | task_id |  status  | nodes_involved
---------------------------------------------------------------------
-  17780 |    1021 | runnable | {61,62}
-  17780 |    1022 | runnable | {61,63}
-  17780 |    1023 | blocked  | {62,61}
-(3 rows)
-
-SELECT D.task_id,
-       (SELECT T.command FROM pg_dist_background_task T WHERE T.task_id = D.task_id),
-       D.depends_on,
-       (SELECT T.command FROM pg_dist_background_task T WHERE T.task_id = D.depends_on)
-FROM pg_dist_background_task_depend D  WHERE job_id in (:job_id) ORDER BY D.task_id, D.depends_on ASC;
- task_id |                               command                               | depends_on |                               command
---------------------------------------------------------------------
-    1023 | SELECT pg_catalog.citus_move_shard_placement(85674054,62,61,'auto') |       1021 | SELECT pg_catalog.citus_move_shard_placement(85674051,61,62,'auto')
-    1023 | SELECT pg_catalog.citus_move_shard_placement(85674054,62,61,'auto') |       1022 | SELECT pg_catalog.citus_move_shard_placement(85674052,61,63,'auto')
-(2 rows)
-
-SELECT citus_rebalance_stop();
- citus_rebalance_stop
---------------------------------------------------------------------
-
-(1 row)
-
-DELETE FROM pg_catalog.pg_dist_rebalance_strategy WHERE name='test_source_then_target';
-DROP SCHEMA background_rebalance_parallel CASCADE;
-TRUNCATE pg_dist_background_job CASCADE;
-TRUNCATE pg_dist_background_task CASCADE;
-TRUNCATE pg_dist_background_task_depend;
-SELECT public.wait_for_resource_cleanup();
- wait_for_resource_cleanup
---------------------------------------------------------------------
-
-(1 row)
-
-select citus_remove_node('localhost', :worker_3_port);
- citus_remove_node
---------------------------------------------------------------------
-
-(1 row)
-
 -- keep the rest of the tests inact that depends node/group ids
 ALTER SEQUENCE pg_catalog.pg_dist_groupid_seq RESTART :last_group_id_cls;
 ALTER SEQUENCE pg_catalog.pg_dist_node_nodeid_seq RESTART :last_node_id_cls;
--- a/src/test/regress/expected/background_task_queue_monitor.out
+++ b/src/test/regress/expected/background_task_queue_monitor.out
@ -3,7 +3,6 @@ SET search_path TO background_task_queue_monitor;
 SET citus.shard_count TO 4;
 SET citus.shard_replication_factor TO 1;
 SET citus.next_shard_id TO 3536400;
-SET client_min_messages TO ERROR;
 -- reset sequence values
 ALTER SEQUENCE pg_dist_background_job_job_id_seq RESTART 1450000;
 ALTER SEQUENCE pg_dist_background_task_task_id_seq RESTART 1450000;
@ -655,268 +654,11 @@ SELECT job_id, task_id, status FROM pg_dist_background_task
 1450016 | 1450024 | done
 (2 rows)

-- TEST11
-- verify that we do not allow parallel task executors involving a particular node
-- more than citus.max_background_task_executors_per_node
-- verify that we can change citus.max_background_task_executors_per_node on the fly
-- tests are done with dummy node ids
-- citus_task_wait calls are used to ensure consistent pg_dist_background_task query
-- output i.e. to avoid flakiness
-BEGIN;
-INSERT INTO pg_dist_background_job (job_type, description) VALUES ('test_job', 'simple test to verify changing max background task executors per node on the fly') RETURNING job_id AS job_id1 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(2); $job$, ARRAY [1, 2]) RETURNING task_id AS task_id1 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(2); $job$, ARRAY [3, 4]) RETURNING task_id AS task_id2 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(4); $job$, ARRAY [1, 2]) RETURNING task_id AS task_id3 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(4); $job$, ARRAY [1, 3]) RETURNING task_id AS task_id4 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(4); $job$, ARRAY [2, 4]) RETURNING task_id AS task_id5 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(7); $job$, ARRAY [1, 2]) RETURNING task_id AS task_id6 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(6); $job$, ARRAY [1, 3]) RETURNING task_id AS task_id7 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(6); $job$, ARRAY [1, 4]) RETURNING task_id AS task_id8 \gset
-COMMIT;
-SELECT citus_task_wait(:task_id1, desired_status => 'running');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_task_wait(:task_id2, desired_status => 'running');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT job_id, task_id, status, nodes_involved FROM pg_dist_background_task
-    WHERE task_id IN (:task_id1, :task_id2, :task_id3, :task_id4,
-                      :task_id5, :task_id6, :task_id7, :task_id8)
-    ORDER BY job_id, task_id; -- show that at most 1 task per node is running
- job_id  | task_id |  status  | nodes_involved
---------------------------------------------------------------------
- 1450017 | 1450025 | running  | {1,2}
- 1450017 | 1450026 | running  | {3,4}
- 1450017 | 1450027 | runnable | {1,2}
- 1450017 | 1450028 | runnable | {1,3}
- 1450017 | 1450029 | runnable | {2,4}
- 1450017 | 1450030 | runnable | {1,2}
- 1450017 | 1450031 | runnable | {1,3}
- 1450017 | 1450032 | runnable | {1,4}
-(8 rows)
-
-SELECT citus_task_wait(:task_id1, desired_status => 'done');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_task_wait(:task_id2, desired_status => 'done');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-- increase max_background_task_executors_per_node on the fly
-ALTER SYSTEM SET citus.max_background_task_executors_per_node = 2;
-SELECT pg_reload_conf();
- pg_reload_conf
---------------------------------------------------------------------
- t
-(1 row)
-
-SELECT citus_task_wait(:task_id3, desired_status => 'running');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_task_wait(:task_id4, desired_status => 'running');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_task_wait(:task_id5, desired_status => 'running');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT job_id, task_id, status, nodes_involved FROM pg_dist_background_task
-    WHERE task_id IN (:task_id1, :task_id2, :task_id3, :task_id4,
-                      :task_id5, :task_id6, :task_id7, :task_id8)
-    ORDER BY job_id, task_id; -- show that at most 2 tasks per node are running
- job_id  | task_id |  status  | nodes_involved
---------------------------------------------------------------------
- 1450017 | 1450025 | done     | {1,2}
- 1450017 | 1450026 | done     | {3,4}
- 1450017 | 1450027 | running  | {1,2}
- 1450017 | 1450028 | running  | {1,3}
- 1450017 | 1450029 | running  | {2,4}
- 1450017 | 1450030 | runnable | {1,2}
- 1450017 | 1450031 | runnable | {1,3}
- 1450017 | 1450032 | runnable | {1,4}
-(8 rows)
-
-- increase to 3 max_background_task_executors_per_node on the fly
-SELECT citus_task_wait(:task_id3, desired_status => 'done');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_task_wait(:task_id4, desired_status => 'done');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_task_wait(:task_id5, desired_status => 'done');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-ALTER SYSTEM SET citus.max_background_task_executors_per_node = 3;
-SELECT pg_reload_conf();
- pg_reload_conf
---------------------------------------------------------------------
- t
-(1 row)
-
-SELECT citus_task_wait(:task_id6, desired_status => 'running');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_task_wait(:task_id7, desired_status => 'running');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_task_wait(:task_id8, desired_status => 'running');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT job_id, task_id, status, nodes_involved FROM pg_dist_background_task
-    WHERE task_id IN (:task_id1, :task_id2, :task_id3, :task_id4,
-                      :task_id5, :task_id6, :task_id7, :task_id8)
-    ORDER BY job_id, task_id; -- show that at most 3 tasks per node are running
- job_id  | task_id | status  | nodes_involved
---------------------------------------------------------------------
- 1450017 | 1450025 | done    | {1,2}
- 1450017 | 1450026 | done    | {3,4}
- 1450017 | 1450027 | done    | {1,2}
- 1450017 | 1450028 | done    | {1,3}
- 1450017 | 1450029 | done    | {2,4}
- 1450017 | 1450030 | running | {1,2}
- 1450017 | 1450031 | running | {1,3}
- 1450017 | 1450032 | running | {1,4}
-(8 rows)
-
-ALTER SYSTEM RESET citus.max_background_task_executors_per_node;
-SELECT pg_reload_conf();
- pg_reload_conf
---------------------------------------------------------------------
- t
-(1 row)
-
-- if pg_cancel_backend is called on one of the running task PIDs
-- task doesn't restart because it's not allowed anymore by the limit.
-- node with id 1 can be used only once, unless there are previously running tasks
-SELECT pid AS task_id6_pid FROM pg_dist_background_task WHERE task_id IN (:task_id6) \gset
-SELECT pg_cancel_backend(:task_id6_pid); -- cancel task_id6 process
- pg_cancel_backend
---------------------------------------------------------------------
- t
-(1 row)
-
-- task goes to only runnable state, not running anymore.
-SELECT citus_task_wait(:task_id6, desired_status => 'runnable');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-- show that cancelled task hasn't restarted because limit doesn't allow it
-SELECT job_id, task_id, status, nodes_involved FROM pg_dist_background_task
-    WHERE task_id IN (:task_id1, :task_id2, :task_id3, :task_id4,
-                      :task_id5, :task_id6, :task_id7, :task_id8)
-    ORDER BY job_id, task_id;
- job_id  | task_id |  status  | nodes_involved
---------------------------------------------------------------------
- 1450017 | 1450025 | done     | {1,2}
- 1450017 | 1450026 | done     | {3,4}
- 1450017 | 1450027 | done     | {1,2}
- 1450017 | 1450028 | done     | {1,3}
- 1450017 | 1450029 | done     | {2,4}
- 1450017 | 1450030 | runnable | {1,2}
- 1450017 | 1450031 | running  | {1,3}
- 1450017 | 1450032 | running  | {1,4}
-(8 rows)
-
-SELECT citus_task_wait(:task_id7, desired_status => 'done');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_task_wait(:task_id8, desired_status => 'done');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_task_wait(:task_id6, desired_status => 'running');
- citus_task_wait
---------------------------------------------------------------------
-
-(1 row)
-
-- show that the 6th task has restarted only after both 6 and 7 are done
-- since we have a limit of 1 background task executor per node with id 1
-SELECT job_id, task_id, status, nodes_involved FROM pg_dist_background_task
-    WHERE task_id IN (:task_id1, :task_id2, :task_id3, :task_id4,
-                      :task_id5, :task_id6, :task_id7, :task_id8)
-    ORDER BY job_id, task_id;
- job_id  | task_id | status  | nodes_involved
---------------------------------------------------------------------
- 1450017 | 1450025 | done    | {1,2}
- 1450017 | 1450026 | done    | {3,4}
- 1450017 | 1450027 | done    | {1,2}
- 1450017 | 1450028 | done    | {1,3}
- 1450017 | 1450029 | done    | {2,4}
- 1450017 | 1450030 | running | {1,2}
- 1450017 | 1450031 | done    | {1,3}
- 1450017 | 1450032 | done    | {1,4}
-(8 rows)
-
-SELECT citus_job_cancel(:job_id1);
- citus_job_cancel
---------------------------------------------------------------------
-
-(1 row)
-
-SELECT citus_job_wait(:job_id1);
- citus_job_wait
---------------------------------------------------------------------
-
-(1 row)
-
-ALTER SYSTEM RESET citus.max_background_task_executors_per_node;
-SELECT pg_reload_conf();
- pg_reload_conf
---------------------------------------------------------------------
- t
-(1 row)
-
 SET client_min_messages TO WARNING;
 TRUNCATE pg_dist_background_job CASCADE;
 TRUNCATE pg_dist_background_task CASCADE;
 TRUNCATE pg_dist_background_task_depend;
 DROP SCHEMA background_task_queue_monitor CASCADE;
-RESET client_min_messages;
 ALTER SYSTEM RESET citus.background_task_queue_interval;
 ALTER SYSTEM RESET citus.max_background_task_executors;
 SELECT pg_reload_conf();
--- a/src/test/regress/expected/multi_extension.out
+++ b/src/test/regress/expected/multi_extension.out
@ -1197,7 +1197,44 @@ SELECT * FROM multi_extension.print_extension_changes();

 -- Test downgrade to 11.1-1 from 11.2-1
 ALTER EXTENSION citus UPDATE TO '11.2-1';
+-- create a table with orphaned shards to see if orphaned shards will be dropped
+-- and cleanup records will be created for them
+SET citus.shard_replication_factor to 1;
+CREATE TABLE table_with_orphaned_shards (a int);
+SELECT create_distributed_table('table_with_orphaned_shards', 'a');
+ create_distributed_table
+---------------------------------------------------------------------
+
+(1 row)
+
+-- show there are 4 placements
+SELECT * FROM pg_dist_placement ORDER BY shardid;
+ placementid | shardid | shardstate | shardlength | groupid
+---------------------------------------------------------------------
+           1 |  102008 |          1 |           0 |       0
+           2 |  102009 |          1 |           0 |       0
+           3 |  102010 |          1 |           0 |       0
+           4 |  102011 |          1 |           0 |       0
+(4 rows)
+
+-- mark two of them as orphaned
+UPDATE pg_dist_placement SET shardstate = 4 WHERE shardid % 2 = 1;
 ALTER EXTENSION citus UPDATE TO '11.1-1';
+-- show placements and cleanup records
+SELECT * FROM pg_dist_placement ORDER BY shardid;
+ placementid | shardid | shardstate | shardlength | groupid
+---------------------------------------------------------------------
+           1 |  102008 |          1 |           0 |       0
+           2 |  102009 |          4 |           0 |       0
+           3 |  102010 |          1 |           0 |       0
+           4 |  102011 |          4 |           0 |       0
+(4 rows)
+
+SELECT * FROM pg_dist_cleanup;
+ record_id | operation_id | object_type | object_name | node_group_id | policy_type
+---------------------------------------------------------------------
+(0 rows)
+
 -- Should be empty result since upgrade+downgrade should be a no-op
 SELECT * FROM multi_extension.print_extension_changes();
 previous_object | current_object
@ -1206,6 +1243,21 @@ SELECT * FROM multi_extension.print_extension_changes();

 -- Snapshot of state at 11.2-1
 ALTER EXTENSION citus UPDATE TO '11.2-1';
+-- verify that the placements are deleted and cleanup records are created
+SELECT * FROM pg_dist_placement ORDER BY shardid;
+ placementid | shardid | shardstate | shardlength | groupid
+---------------------------------------------------------------------
+           1 |  102008 |          1 |           0 |       0
+           3 |  102010 |          1 |           0 |       0
+(2 rows)
+
+SELECT * FROM pg_dist_cleanup;
+ record_id | operation_id | object_type |            object_name            | node_group_id | policy_type
+---------------------------------------------------------------------
+         1 |            0 |           1 | table_with_orphaned_shards_102009 |             0 |           0
+         2 |            0 |           1 | table_with_orphaned_shards_102011 |             0 |           0
+(2 rows)
+
 ALTER EXTENSION citus_columnar UPDATE TO '11.2-1';
 -- Make sure that we defined dependencies from all rel objects (tables,
 -- indexes, sequences ..) to columnar table access method ...
@ -1243,6 +1295,16 @@ SELECT COUNT(*)=5 FROM columnar_schema_members_pg_depend;
 (1 row)

 DROP TABLE columnar_schema_members, columnar_schema_members_pg_depend;
+-- error out as cleanup records remain
+ALTER EXTENSION citus UPDATE TO '11.0-4';
+ERROR:  pg_dist_cleanup is introduced in Citus 11.1
+HINT:  To downgrade Citus to an older version, you should first cleanup all the orphaned resources and make sure pg_dist_cleanup is empty, by executing CALL citus_cleanup_orphaned_resources();
+CONTEXT:  PL/pgSQL function inline_code_block line XX at RAISE
+-- cleanup
+SET client_min_messages TO ERROR;
+CALL citus_cleanup_orphaned_resources();
+DROP TABLE table_with_orphaned_shards;
+RESET client_min_messages;
 SELECT * FROM multi_extension.print_extension_changes();
                                                                                                                                    previous_object                                                                                                                                     |                                                                                                                                                              current_object
 ---------------------------------------------------------------------
@ -1286,26 +1348,9 @@ SELECT * FROM multi_extension.print_extension_changes();
                                                                                                                                                                                                                                                                                        | type cluster_clock
 (38 rows)

-- Test downgrade to 11.2-1 from 11.2-2
-ALTER EXTENSION citus UPDATE TO '11.2-2';
-ALTER EXTENSION citus UPDATE TO '11.2-1';
-- Should be empty result since upgrade+downgrade should be a no-op
-SELECT * FROM multi_extension.print_extension_changes();
- previous_object | current_object
---------------------------------------------------------------------
-(0 rows)
-
-- Snapshot of state at 11.2-2
-ALTER EXTENSION citus UPDATE TO '11.2-2';
-SELECT * FROM multi_extension.print_extension_changes();
- previous_object |                          current_object
---------------------------------------------------------------------
-                 | function worker_adjust_identity_column_seq_ranges(regclass) void
-(1 row)
-
-- Test downgrade to 11.2-2 from 11.3-1
+-- Test downgrade to 11.2-1 from 11.3-1
 ALTER EXTENSION citus UPDATE TO '11.3-1';
-ALTER EXTENSION citus UPDATE TO '11.2-2';
+ALTER EXTENSION citus UPDATE TO '11.2-1';
 -- Should be empty result since upgrade+downgrade should be a no-op
 SELECT * FROM multi_extension.print_extension_changes();
 previous_object | current_object
@ -1325,10 +1370,11 @@ SELECT * FROM multi_extension.print_extension_changes();
                 | function citus_stat_tenants_local(boolean) SETOF record
                 | function citus_stat_tenants_local_reset() void
                 | function citus_stat_tenants_reset() void
+                 | function worker_adjust_identity_column_seq_ranges(regclass) void
                 | function worker_drop_all_shell_tables(boolean)
                 | view citus_stat_tenants
                 | view citus_stat_tenants_local
-(11 rows)
+(12 rows)

 DROP TABLE multi_extension.prev_objects, multi_extension.extension_diff;
 -- show running version
--- a/src/test/regress/expected/multi_metadata_attributes.out
+++ b/src/test/regress/expected/multi_metadata_attributes.out
@ -9,8 +9,7 @@ FROM pg_attribute
 WHERE atthasmissing AND attrelid NOT IN ('pg_dist_node'::regclass,
                                         'pg_dist_rebalance_strategy'::regclass,
                                         'pg_dist_partition'::regclass,
-                                         'pg_dist_object'::regclass,
-                                         'pg_dist_background_task'::regclass)
+                                         'pg_dist_object'::regclass)
 ORDER BY attrelid, attname;
 attrelid | attname | atthasmissing | attmissingval
 ---------------------------------------------------------------------
--- a/src/test/regress/expected/multi_metadata_sync.out
+++ b/src/test/regress/expected/multi_metadata_sync.out
@ -497,7 +497,7 @@ SELECT * FROM pg_dist_node ORDER BY nodeid;
      5 |       1 | localhost |     8889 | default  | f           | t        | secondary | second-cluster | f              | t
 (4 rows)

-SELECT * FROM pg_dist_partition WHERE logicalrelid::text LIKE 'mx_testing_schema%' ORDER BY logicalrelid::text;
+SELECT * FROM pg_dist_partition WHERE logicalrelid::text LIKE 'mx_testing_schema%' ORDER BY logicalrelid;
          logicalrelid           | partmethod |                                                         partkey                                                          | colocationid | repmodel | autoconverted
 ---------------------------------------------------------------------
 mx_testing_schema.mx_test_table | h          | {VAR :varno 1 :varattno 1 :vartype 23 :vartypmod -1 :varcollid 0 :varlevelsup 0 :varnosyn 1 :varattnosyn 1 :location -1} |            2 | s        | f
@ -635,7 +635,7 @@ SELECT * FROM pg_dist_node ORDER BY nodeid;
      5 |       1 | localhost |     8889 | default  | f           | t        | secondary | second-cluster | f              | t
 (4 rows)

-SELECT * FROM pg_dist_partition WHERE logicalrelid::text LIKE 'mx_testing_schema%' ORDER BY logicalrelid::text;
+SELECT * FROM pg_dist_partition WHERE logicalrelid::text LIKE 'mx_testing_schema%' ORDER BY logicalrelid;
          logicalrelid           | partmethod |                                                         partkey                                                          | colocationid | repmodel | autoconverted
 ---------------------------------------------------------------------
 mx_testing_schema.mx_test_table | h          | {VAR :varno 1 :varattno 1 :vartype 23 :vartypmod -1 :varcollid 0 :varlevelsup 0 :varnosyn 1 :varattnosyn 1 :location -1} |            2 | s        | f
@ -872,7 +872,7 @@ WHERE
 	logicalrelid = 'mx_test_schema_1.mx_table_1'::regclass
 	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass
 ORDER BY
-	logicalrelid::text;
+	logicalrelid;
        logicalrelid         | repmodel
 ---------------------------------------------------------------------
 mx_test_schema_1.mx_table_1 | s
@ -888,7 +888,7 @@ WHERE
 	logicalrelid = 'mx_test_schema_1.mx_table_1'::regclass
 	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass
 ORDER BY
-	logicalrelid::text, shardid;
+	logicalrelid, shardid;
        logicalrelid         | shardid | nodename  | nodeport
 ---------------------------------------------------------------------
 mx_test_schema_1.mx_table_1 | 1310020 | localhost |    57637
@ -921,9 +921,7 @@ FROM
 	pg_dist_partition
 WHERE
 	logicalrelid = 'mx_test_schema_1.mx_table_1'::regclass
-	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass
-ORDER BY
-	logicalrelid::text;
+	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass;
        logicalrelid         | repmodel
 ---------------------------------------------------------------------
 mx_test_schema_1.mx_table_1 | s
@ -939,7 +937,7 @@ WHERE
 	logicalrelid = 'mx_test_schema_1.mx_table_1'::regclass
 	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass
 ORDER BY
-	logicalrelid::text, shardid;
+	logicalrelid, shardid;
        logicalrelid         | shardid | nodename  | nodeport
 ---------------------------------------------------------------------
 mx_test_schema_1.mx_table_1 | 1310020 | localhost |    57637
@ -1083,7 +1081,7 @@ FROM
 WHERE
 	logicalrelid = 'mx_colocation_test_1'::regclass
 	OR logicalrelid = 'mx_colocation_test_2'::regclass
-ORDER BY logicalrelid::text;
+ORDER BY logicalrelid;
     logicalrelid     | colocationid
 ---------------------------------------------------------------------
 mx_colocation_test_1 |        10000
@ -1103,13 +1101,11 @@ FROM
 	pg_dist_partition
 WHERE
 	logicalrelid = 'mx_colocation_test_1'::regclass
-	OR logicalrelid = 'mx_colocation_test_2'::regclass
-ORDER BY
-	logicalrelid::text;
+	OR logicalrelid = 'mx_colocation_test_2'::regclass;
     logicalrelid     | colocationid
 ---------------------------------------------------------------------
- mx_colocation_test_1 |        10001
 mx_colocation_test_2 |        10001
+ mx_colocation_test_1 |        10001
 (2 rows)

 \c - - - :worker_1_port
@ -1119,13 +1115,11 @@ FROM
 	pg_dist_partition
 WHERE
 	logicalrelid = 'mx_colocation_test_1'::regclass
-	OR logicalrelid = 'mx_colocation_test_2'::regclass
-ORDER BY
-	logicalrelid::text;
+	OR logicalrelid = 'mx_colocation_test_2'::regclass;
     logicalrelid     | colocationid
 ---------------------------------------------------------------------
- mx_colocation_test_1 |        10001
 mx_colocation_test_2 |        10001
+ mx_colocation_test_1 |        10001
 (2 rows)

 \c - - - :master_port
--- a/src/test/regress/expected/multi_metadata_sync_0.out
+++ b/src/test/regress/expected/multi_metadata_sync_0.out
@ -497,7 +497,7 @@ SELECT * FROM pg_dist_node ORDER BY nodeid;
      5 |       1 | localhost |     8889 | default  | f           | t        | secondary | second-cluster | f              | t
 (4 rows)

-SELECT * FROM pg_dist_partition WHERE logicalrelid::text LIKE 'mx_testing_schema%' ORDER BY logicalrelid::text;
+SELECT * FROM pg_dist_partition WHERE logicalrelid::text LIKE 'mx_testing_schema%' ORDER BY logicalrelid;
          logicalrelid           | partmethod |                                                         partkey                                                          | colocationid | repmodel | autoconverted
 ---------------------------------------------------------------------
 mx_testing_schema.mx_test_table | h          | {VAR :varno 1 :varattno 1 :vartype 23 :vartypmod -1 :varcollid 0 :varlevelsup 0 :varnosyn 1 :varattnosyn 1 :location -1} |            2 | s        | f
@ -635,7 +635,7 @@ SELECT * FROM pg_dist_node ORDER BY nodeid;
      5 |       1 | localhost |     8889 | default  | f           | t        | secondary | second-cluster | f              | t
 (4 rows)

-SELECT * FROM pg_dist_partition WHERE logicalrelid::text LIKE 'mx_testing_schema%' ORDER BY logicalrelid::text;
+SELECT * FROM pg_dist_partition WHERE logicalrelid::text LIKE 'mx_testing_schema%' ORDER BY logicalrelid;
          logicalrelid           | partmethod |                                                         partkey                                                          | colocationid | repmodel | autoconverted
 ---------------------------------------------------------------------
 mx_testing_schema.mx_test_table | h          | {VAR :varno 1 :varattno 1 :vartype 23 :vartypmod -1 :varcollid 0 :varlevelsup 0 :varnosyn 1 :varattnosyn 1 :location -1} |            2 | s        | f
@ -872,7 +872,7 @@ WHERE
 	logicalrelid = 'mx_test_schema_1.mx_table_1'::regclass
 	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass
 ORDER BY
-	logicalrelid::text;
+	logicalrelid;
        logicalrelid         | repmodel
 ---------------------------------------------------------------------
 mx_test_schema_1.mx_table_1 | s
@ -888,7 +888,7 @@ WHERE
 	logicalrelid = 'mx_test_schema_1.mx_table_1'::regclass
 	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass
 ORDER BY
-	logicalrelid::text, shardid;
+	logicalrelid, shardid;
        logicalrelid         | shardid | nodename  | nodeport
 ---------------------------------------------------------------------
 mx_test_schema_1.mx_table_1 | 1310020 | localhost |    57637
@ -921,9 +921,7 @@ FROM
 	pg_dist_partition
 WHERE
 	logicalrelid = 'mx_test_schema_1.mx_table_1'::regclass
-	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass
-ORDER BY
-	logicalrelid::text;
+	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass;
        logicalrelid         | repmodel
 ---------------------------------------------------------------------
 mx_test_schema_1.mx_table_1 | s
@ -939,7 +937,7 @@ WHERE
 	logicalrelid = 'mx_test_schema_1.mx_table_1'::regclass
 	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass
 ORDER BY
-	logicalrelid::text, shardid;
+	logicalrelid, shardid;
        logicalrelid         | shardid | nodename  | nodeport
 ---------------------------------------------------------------------
 mx_test_schema_1.mx_table_1 | 1310020 | localhost |    57637
@ -1083,7 +1081,7 @@ FROM
 WHERE
 	logicalrelid = 'mx_colocation_test_1'::regclass
 	OR logicalrelid = 'mx_colocation_test_2'::regclass
-ORDER BY logicalrelid::text;
+ORDER BY logicalrelid;
     logicalrelid     | colocationid
 ---------------------------------------------------------------------
 mx_colocation_test_1 |        10000
@ -1103,13 +1101,11 @@ FROM
 	pg_dist_partition
 WHERE
 	logicalrelid = 'mx_colocation_test_1'::regclass
-	OR logicalrelid = 'mx_colocation_test_2'::regclass
-ORDER BY
-	logicalrelid::text;
+	OR logicalrelid = 'mx_colocation_test_2'::regclass;
     logicalrelid     | colocationid
 ---------------------------------------------------------------------
- mx_colocation_test_1 |        10001
 mx_colocation_test_2 |        10001
+ mx_colocation_test_1 |        10001
 (2 rows)

 \c - - - :worker_1_port
@ -1119,13 +1115,11 @@ FROM
 	pg_dist_partition
 WHERE
 	logicalrelid = 'mx_colocation_test_1'::regclass
-	OR logicalrelid = 'mx_colocation_test_2'::regclass
-ORDER BY
-	logicalrelid::text;
+	OR logicalrelid = 'mx_colocation_test_2'::regclass;
     logicalrelid     | colocationid
 ---------------------------------------------------------------------
- mx_colocation_test_1 |        10001
 mx_colocation_test_2 |        10001
+ mx_colocation_test_1 |        10001
 (2 rows)

 \c - - - :master_port
--- a/src/test/regress/expected/upgrade_basic_after.out
+++ b/src/test/regress/expected/upgrade_basic_after.out
@ -39,29 +39,16 @@ SELECT nextval('pg_dist_colocationid_seq') = MAX(colocationid)+1 FROM pg_dist_co
 t
 (1 row)

-- while testing sequences on pg_dist_cleanup, they return null in pg upgrade schedule
-- but return a valid value in citus upgrade schedule
-- that's why we accept both NULL and MAX()+1 here
-SELECT
-    CASE WHEN MAX(operation_id) IS NULL
-    THEN true
-    ELSE nextval('pg_dist_operationid_seq') = MAX(operation_id)+1
-    END AS check_operationid
-    FROM pg_dist_cleanup;
- check_operationid
+SELECT nextval('pg_dist_operationid_seq') = MAX(operation_id)+1 FROM pg_dist_cleanup;
+ ?column?
 ---------------------------------------------------------------------
- t
+
 (1 row)

-SELECT
-    CASE WHEN MAX(record_id) IS NULL
-    THEN true
-    ELSE nextval('pg_dist_cleanup_recordid_seq') = MAX(record_id)+1
-    END AS check_recordid
-    FROM pg_dist_cleanup;
- check_recordid
+SELECT nextval('pg_dist_cleanup_recordid_seq') = MAX(record_id)+1 FROM pg_dist_cleanup;
+ ?column?
 ---------------------------------------------------------------------
- t
+
 (1 row)

 SELECT nextval('pg_dist_background_job_job_id_seq') > COALESCE(MAX(job_id), 0) FROM pg_dist_background_job;
--- a/src/test/regress/expected/upgrade_pg_dist_cleanup_after.out
+++ b/src/test/regress/expected/upgrade_pg_dist_cleanup_after.out
@ -1,13 +0,0 @@
-\set upgrade_test_old_citus_version `echo "$CITUS_OLD_VERSION"`
-SELECT substring(:'upgrade_test_old_citus_version', 'v(\d+)\.\d+\.\d+')::int > 11 OR
-       (substring(:'upgrade_test_old_citus_version', 'v(\d+)\.\d+\.\d+')::int = 11 AND
-        substring(:'upgrade_test_old_citus_version', 'v\d+\.(\d+)\.\d+')::int >= 2)
-AS upgrade_test_old_citus_version_gte_11_2;
- upgrade_test_old_citus_version_gte_11_2
---------------------------------------------------------------------
- t
-(1 row)
-
-\gset
-\if :upgrade_test_old_citus_version_gte_11_2
-\q
--- a/src/test/regress/expected/upgrade_pg_dist_cleanup_after_0.out
+++ b/src/test/regress/expected/upgrade_pg_dist_cleanup_after_0.out
@ -1,30 +0,0 @@
-\set upgrade_test_old_citus_version `echo "$CITUS_OLD_VERSION"`
-SELECT substring(:'upgrade_test_old_citus_version', 'v(\d+)\.\d+\.\d+')::int > 11 OR
-       (substring(:'upgrade_test_old_citus_version', 'v(\d+)\.\d+\.\d+')::int = 11 AND
-        substring(:'upgrade_test_old_citus_version', 'v\d+\.(\d+)\.\d+')::int >= 2)
-AS upgrade_test_old_citus_version_gte_11_2;
- upgrade_test_old_citus_version_gte_11_2
---------------------------------------------------------------------
- f
-(1 row)
-
-\gset
-\if :upgrade_test_old_citus_version_gte_11_2
-\q
-\endif
-- verify that the orphaned placement is deleted and cleanup record is created
-SELECT COUNT(*) FROM pg_dist_placement WHERE shardid IN (SELECT shardid FROM pg_dist_shard WHERE logicalrelid='table_with_orphaned_shards'::regclass);
- count
---------------------------------------------------------------------
-    32
-(1 row)
-
-SELECT * FROM pg_dist_cleanup;
- record_id | operation_id | object_type |            object_name            | node_group_id | policy_type
---------------------------------------------------------------------
-         1 |            0 |           1 | table_with_orphaned_shards_980001 |             1 |           0
-(1 row)
-
-CALL citus_cleanup_orphaned_resources();
-NOTICE:  cleaned up 1 orphaned resources
-DROP TABLE table_with_orphaned_shards;
--- a/src/test/regress/expected/upgrade_pg_dist_cleanup_before.out
+++ b/src/test/regress/expected/upgrade_pg_dist_cleanup_before.out
@ -1,13 +0,0 @@
-\set upgrade_test_old_citus_version `echo "$CITUS_OLD_VERSION"`
-SELECT substring(:'upgrade_test_old_citus_version', 'v(\d+)\.\d+\.\d+')::int > 11 OR
-       (substring(:'upgrade_test_old_citus_version', 'v(\d+)\.\d+\.\d+')::int = 11 AND
-        substring(:'upgrade_test_old_citus_version', 'v\d+\.(\d+)\.\d+')::int >= 2)
-AS upgrade_test_old_citus_version_gte_11_2;
- upgrade_test_old_citus_version_gte_11_2
---------------------------------------------------------------------
- t
-(1 row)
-
-\gset
-\if :upgrade_test_old_citus_version_gte_11_2
-\q
--- a/src/test/regress/expected/upgrade_pg_dist_cleanup_before_0.out
+++ b/src/test/regress/expected/upgrade_pg_dist_cleanup_before_0.out
@ -1,36 +0,0 @@
-\set upgrade_test_old_citus_version `echo "$CITUS_OLD_VERSION"`
-SELECT substring(:'upgrade_test_old_citus_version', 'v(\d+)\.\d+\.\d+')::int > 11 OR
-       (substring(:'upgrade_test_old_citus_version', 'v(\d+)\.\d+\.\d+')::int = 11 AND
-        substring(:'upgrade_test_old_citus_version', 'v\d+\.(\d+)\.\d+')::int >= 2)
-AS upgrade_test_old_citus_version_gte_11_2;
- upgrade_test_old_citus_version_gte_11_2
---------------------------------------------------------------------
- f
-(1 row)
-
-\gset
-\if :upgrade_test_old_citus_version_gte_11_2
-\q
-\endif
-- create a table with orphaned shards to see if orphaned shards will be dropped
-- and cleanup records will be created for them
-SET citus.next_shard_id TO 980000;
-CREATE TABLE table_with_orphaned_shards (a int);
-SELECT create_distributed_table('table_with_orphaned_shards', 'a');
- create_distributed_table
---------------------------------------------------------------------
-
-(1 row)
-
-- show all 32 placements are active
-SELECT COUNT(*) FROM pg_dist_placement WHERE shardstate = 1 AND shardid IN (SELECT shardid FROM pg_dist_shard WHERE logicalrelid='table_with_orphaned_shards'::regclass);
- count
---------------------------------------------------------------------
-    32
-(1 row)
-
-- create an orphaned placement based on an existing one
-INSERT INTO pg_dist_placement(placementid, shardid, shardstate, shardlength, groupid)
-    SELECT nextval('pg_dist_placement_placementid_seq'::regclass), shardid, 4, shardlength, 3-groupid
-    FROM pg_dist_placement
-    WHERE shardid = 980001;
--- a/src/test/regress/sql/background_rebalance_parallel.sql
+++ b/src/test/regress/sql/background_rebalance_parallel.sql
@ -1,22 +1,12 @@
--
-- BACKGROUND_REBALANCE_PARALLEL
--
-- Test to check if the background tasks scheduled by the background rebalancer
-- have the correct dependencies
--
-- Test to verify that we do not allow parallel rebalancer moves involving a
-- particular node (either as source or target) more than
-- citus.max_background_task_executors_per_node, and that we can change the GUC on
-- the fly, and that will affect the ongoing balance as it should
--
-- Test to verify that there's a hard dependency when a specific node is first being
-- used as a source for a move, and then later as a target.
--
+/*
+  Test to check if the background tasks scheduled by the background rebalancer
+  has the correct dependencies.
+*/
 CREATE SCHEMA background_rebalance_parallel;
 SET search_path TO background_rebalance_parallel;
 SET citus.next_shard_id TO 85674000;
 SET citus.shard_replication_factor TO 1;
-SET client_min_messages TO ERROR;
+SET client_min_messages TO WARNING;

 ALTER SEQUENCE pg_dist_background_job_job_id_seq RESTART 17777;
 ALTER SEQUENCE pg_dist_background_task_task_id_seq RESTART 1000;
@ -36,7 +26,7 @@ SELECT 1 FROM master_add_node('localhost', :worker_2_port);
 ALTER SYSTEM SET citus.background_task_queue_interval TO '1s';
 SELECT pg_reload_conf();

-- Colocation group 1: create two tables table1_colg1, table2_colg1 and in a colocation group
+/* Colocation group 1: create two tables table1_colg1, table2_colg1 and in a colocation group  */
 CREATE TABLE table1_colg1 (a int PRIMARY KEY);
 SELECT create_distributed_table('table1_colg1', 'a', shard_count => 4 , colocate_with => 'none');

@ -44,7 +34,7 @@ CREATE TABLE table2_colg1 (b int PRIMARY KEY);

 SELECT create_distributed_table('table2_colg1', 'b' , colocate_with => 'table1_colg1');

-- Colocation group 2: create two tables table1_colg2, table2_colg2 and in a colocation group
+/* Colocation group 2: create two tables table1_colg2, table2_colg2 and in a colocation group  */
 CREATE TABLE table1_colg2 (a int PRIMARY KEY);

 SELECT create_distributed_table('table1_colg2 ', 'a', shard_count => 4, colocate_with => 'none');
@ -53,7 +43,7 @@ CREATE TABLE  table2_colg2 (b int primary key);

 SELECT create_distributed_table('table2_colg2', 'b' , colocate_with => 'table1_colg2');

-- Colocation group 3: create two tables table1_colg3, table2_colg3 and in a colocation group
+/* Colocation group 3: create two tables table1_colg3, table2_colg3 and in a colocation group  */
 CREATE TABLE table1_colg3 (a int PRIMARY KEY);

 SELECT create_distributed_table('table1_colg3 ', 'a', shard_count => 4, colocate_with => 'none');
@ -63,7 +53,7 @@ CREATE TABLE  table2_colg3 (b int primary key);
 SELECT create_distributed_table('table2_colg3', 'b' , colocate_with => 'table1_colg3');


-- Add two new nodes so that we can rebalance
+/* Add two new node so that we can rebalance */
 SELECT 1 FROM citus_add_node('localhost', :worker_3_port);
 SELECT 1 FROM citus_add_node('localhost', :worker_4_port);

@ -73,12 +63,10 @@ SELECT * FROM citus_rebalance_start();

 SELECT citus_rebalance_wait();

-- PART 1
-- Test to check if the background tasks scheduled by the background rebalancer
-- have the correct dependencies
-
-- Check that a move is dependent on
-- any other move scheduled earlier in its colocation group.
+/*Check that a move is dependent on
+	1. any other move scheduled earlier in its colocation group.
+	2. any other move scheduled earlier whose source node or target
+	   node overlaps with the current moves nodes. */
 SELECT S.shardid, P.colocationid
 FROM pg_dist_shard S, pg_dist_partition P
 WHERE S.logicalrelid = P.logicalrelid ORDER BY S.shardid ASC;
@ -90,14 +78,14 @@ SELECT D.task_id,
 FROM pg_dist_background_task_depend D  WHERE job_id = 17777 ORDER BY D.task_id, D.depends_on ASC;


-- Check that if there is a reference table that needs to be synched to a node,
-- any move without a dependency must depend on the move task for reference table.
+/* Check that if there is a reference table that needs to be synched to a node,
+   any move without a dependency must depend on the move task for reference table. */
 SELECT 1 FROM citus_drain_node('localhost',:worker_4_port);
 SELECT public.wait_for_resource_cleanup();
 SELECT 1 FROM citus_disable_node('localhost', :worker_4_port, synchronous:=true);

-- Drain worker_3 so that we can move only one colocation group to worker_3
-- to create an unbalance that would cause parallel rebalancing.
+/* Drain worker_3 so that we can move only one colocation group to worker_3
+   to create an unbalance that would cause parallel rebalancing. */
 SELECT 1 FROM citus_drain_node('localhost',:worker_3_port);
 SELECT citus_set_node_property('localhost', :worker_3_port, 'shouldhaveshards', true);

@ -107,7 +95,7 @@ CREATE TABLE ref_table(a int PRIMARY KEY);

 SELECT create_reference_table('ref_table');

-- Move all the shards of Colocation group 3 to worker_3.
+/* Move all the shards of Colocation group 3 to worker_3.*/
 SELECT
 master_move_shard_placement(shardid, 'localhost', nodeport, 'localhost', :worker_3_port, 'block_writes')
 FROM
@ -119,7 +107,7 @@ ORDER BY

 CALL citus_cleanup_orphaned_resources();

-- Activate and new  nodes so that we can rebalance.
+/* Activate and new  nodes so that we can rebalance. */
 SELECT 1 FROM citus_activate_node('localhost', :worker_4_port);
 SELECT citus_set_node_property('localhost', :worker_4_port, 'shouldhaveshards', true);

@ -140,265 +128,13 @@ SELECT D.task_id,
       (SELECT T.command FROM pg_dist_background_task T WHERE T.task_id = D.depends_on)
 FROM pg_dist_background_task_depend D  WHERE job_id = 17778 ORDER BY D.task_id, D.depends_on ASC;

-- PART 2
-- Test to verify that we do not allow parallel rebalancer moves involving a
-- particular node (either as source or target)
-- more than citus.max_background_task_executors_per_node
-- and that we can change the GUC on the fly
-- citus_task_wait calls are used to ensure consistent pg_dist_background_task query
-- output i.e. to avoid flakiness
-
-- First let's restart the scenario
 DROP SCHEMA background_rebalance_parallel CASCADE;
 TRUNCATE pg_dist_background_job CASCADE;
-TRUNCATE pg_dist_background_task CASCADE;
-TRUNCATE pg_dist_background_task_depend;
 SELECT public.wait_for_resource_cleanup();
-select citus_remove_node('localhost', :worker_2_port);
 select citus_remove_node('localhost', :worker_3_port);
 select citus_remove_node('localhost', :worker_4_port);
 select citus_remove_node('localhost', :worker_5_port);
 select citus_remove_node('localhost', :worker_6_port);
-CREATE SCHEMA background_rebalance_parallel;
-SET search_path TO background_rebalance_parallel;
-
-- Create 8 tables in 4 colocation groups, and populate them
-CREATE TABLE table1_colg1 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg1', 'a', shard_count => 3, colocate_with => 'none');
-INSERT INTO table1_colg1 SELECT i FROM generate_series(0, 100)i;
-
-CREATE TABLE table2_colg1 (b int PRIMARY KEY);
-SELECT create_distributed_table('table2_colg1', 'b', colocate_with => 'table1_colg1');
-INSERT INTO table2_colg1 SELECT i FROM generate_series(0, 100)i;
-
-CREATE TABLE table1_colg2 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg2', 'a', shard_count => 3, colocate_with => 'none');
-INSERT INTO table1_colg2 SELECT i FROM generate_series(0, 100)i;
-
-CREATE TABLE table2_colg2 (b int PRIMARY KEY);
-SELECT create_distributed_table('table2_colg2', 'b', colocate_with => 'table1_colg2');
-INSERT INTO table2_colg2 SELECT i FROM generate_series(0, 100)i;
-
-CREATE TABLE table1_colg3 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg3', 'a', shard_count => 3, colocate_with => 'none');
-INSERT INTO table1_colg3 SELECT i FROM generate_series(0, 100)i;
-
-CREATE TABLE  table2_colg3 (b int primary key);
-SELECT create_distributed_table('table2_colg3', 'b', colocate_with => 'table1_colg3');
-INSERT INTO table2_colg3 SELECT i FROM generate_series(0, 100)i;
-
-CREATE TABLE table1_colg4 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg4', 'a', shard_count => 3, colocate_with => 'none');
-INSERT INTO table1_colg4 SELECT i FROM generate_series(0, 100)i;
-
-CREATE TABLE table2_colg4 (b int PRIMARY KEY);
-SELECT create_distributed_table('table2_colg4', 'b', colocate_with => 'table1_colg4');
-INSERT INTO table2_colg4 SELECT i FROM generate_series(0, 100)i;
-
-- Add nodes so that we can rebalance
-SELECT citus_add_node('localhost', :worker_2_port);
-SELECT citus_add_node('localhost', :worker_3_port);
-
-SELECT citus_rebalance_start AS job_id from citus_rebalance_start() \gset
-
-- see dependent tasks to understand which tasks remain runnable because of
-- citus.max_background_task_executors_per_node
-- and which tasks are actually blocked from colocation group dependencies
-SELECT D.task_id,
-       (SELECT T.command FROM pg_dist_background_task T WHERE T.task_id = D.task_id),
-       D.depends_on,
-       (SELECT T.command FROM pg_dist_background_task T WHERE T.task_id = D.depends_on)
-FROM pg_dist_background_task_depend D  WHERE job_id in (:job_id) ORDER BY D.task_id, D.depends_on ASC;
-
-- default citus.max_background_task_executors_per_node is 1
-- show that first exactly one task per node is running
-- among the tasks that are not blocked
-SELECT citus_task_wait(1013, desired_status => 'running');
-SELECT job_id, task_id, status, nodes_involved
-FROM pg_dist_background_task WHERE job_id in (:job_id) ORDER BY task_id;
-
-- increase citus.max_background_task_executors_per_node
-ALTER SYSTEM SET citus.max_background_task_executors_per_node = 2;
-SELECT pg_reload_conf();
-SELECT citus_task_wait(1015, desired_status => 'running');
-SELECT citus_task_wait(1013, desired_status => 'done');
-
-- show that at most 2 tasks per node are running
-- among the tasks that are not blocked
-SELECT job_id, task_id, status, nodes_involved
-FROM pg_dist_background_task WHERE job_id in (:job_id) ORDER BY task_id;
-
-- decrease to default (1)
-ALTER SYSTEM RESET citus.max_background_task_executors_per_node;
-SELECT pg_reload_conf();
-SELECT citus_task_wait(1015, desired_status => 'done');
-SELECT citus_task_wait(1014, desired_status => 'done');
-SELECT citus_task_wait(1016, desired_status => 'running');
-
-- show that exactly one task per node is running
-- among the tasks that are not blocked
-SELECT job_id, task_id, status, nodes_involved
-FROM pg_dist_background_task WHERE job_id in (:job_id) ORDER BY task_id;
-
-SELECT citus_rebalance_stop();
-
-- PART 3
-- Test to verify that there's a hard dependency when A specific node is first being used as a
-- source for a move, and then later as a target.
-
-- First let's restart the scenario
-DROP SCHEMA background_rebalance_parallel CASCADE;
-TRUNCATE pg_dist_background_job CASCADE;
-TRUNCATE pg_dist_background_task CASCADE;
-TRUNCATE pg_dist_background_task_depend;
-SELECT public.wait_for_resource_cleanup();
-select citus_remove_node('localhost', :worker_1_port);
-select citus_remove_node('localhost', :worker_2_port);
-select citus_remove_node('localhost', :worker_3_port);
-CREATE SCHEMA background_rebalance_parallel;
-SET search_path TO background_rebalance_parallel;
-SET citus.next_shard_id TO 85674051;
-ALTER SEQUENCE pg_catalog.pg_dist_node_nodeid_seq RESTART 61;
-
-- add the first node
-- nodeid here is 61
-select citus_add_node('localhost', :worker_1_port);
-
-- create, populate and distribute 6 tables, each with 1 shard, none colocated with each other
-CREATE TABLE table1_colg1 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg1', 'a', shard_count => 1, colocate_with => 'none');
-INSERT INTO table1_colg1 SELECT i FROM generate_series(0, 100)i;
-
-CREATE TABLE table1_colg2 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg2', 'a', shard_count => 1, colocate_with => 'none');
-INSERT INTO table1_colg2 SELECT i FROM generate_series(0, 100)i;
-
-CREATE TABLE table1_colg3 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg3', 'a', shard_count => 1, colocate_with => 'none');
-INSERT INTO table1_colg3 SELECT i FROM generate_series(0, 100)i;
-
-CREATE TABLE table1_colg4 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg4', 'a', shard_count => 1, colocate_with => 'none');
-INSERT INTO table1_colg4 SELECT i FROM generate_series(0, 100)i;
-
-CREATE TABLE table1_colg5 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg5', 'a', shard_count => 1, colocate_with => 'none');
-INSERT INTO table1_colg5 SELECT i FROM generate_series(0, 100)i;
-
-CREATE TABLE table1_colg6 (a int PRIMARY KEY);
-SELECT create_distributed_table('table1_colg6', 'a', shard_count => 1, colocate_with => 'none');
-INSERT INTO table1_colg6 SELECT i FROM generate_series(0, 100)i;
-
-- add two other nodes
-- nodeid here is 62
-select citus_add_node('localhost', :worker_2_port);
-- nodeid here is 63
-select citus_add_node('localhost', :worker_3_port);
-
-CREATE OR REPLACE FUNCTION shard_placement_rebalance_array(
-    worker_node_list json[],
-    shard_placement_list json[],
-    threshold float4 DEFAULT 0,
-    max_shard_moves int DEFAULT 1000000,
-    drain_only bool DEFAULT false,
-    improvement_threshold float4 DEFAULT 0.5
-)
-RETURNS json[]
-AS 'citus'
-LANGUAGE C STRICT VOLATILE;
-
-- we are simulating the following from shard_rebalancer_unit.sql
-- the following steps are all according to this scenario
-- where the third move should be dependent of the first two
-- because the third move's target is the source of the first two
-SELECT unnest(shard_placement_rebalance_array(
-    ARRAY['{"node_name": "hostname1", "disallowed_shards": "1,2,3,5,6"}',
-          '{"node_name": "hostname2", "disallowed_shards": "4"}',
-          '{"node_name": "hostname3", "disallowed_shards": "4"}'
-        ]::json[],
-    ARRAY['{"shardid":1, "nodename":"hostname1"}',
-          '{"shardid":2, "nodename":"hostname1"}',
-          '{"shardid":3, "nodename":"hostname2"}',
-          '{"shardid":4, "nodename":"hostname2"}',
-          '{"shardid":5, "nodename":"hostname3"}',
-          '{"shardid":6, "nodename":"hostname3"}'
-        ]::json[]
-));
-
-- manually balance the cluster such that we have
-- a balanced cluster like above with 1,2,3,4,5,6 and hostname1/2/3
-- shardid 85674051 (1) nodeid 61 (hostname1)
-- shardid 85674052 (2) nodeid 61 (hostname1)
-- shardid 85674053 (3) nodeid 62 (hostname2)
-- shardid 85674054 (4) nodeid 62 (hostname2)
-- shardid 85674055 (5) nodeid 63 (hostname3)
-- shardid 85674056 (6) nodeid 63 (hostname3)
-SELECT pg_catalog.citus_move_shard_placement(85674053,61,62,'auto');
-SELECT pg_catalog.citus_move_shard_placement(85674054,61,62,'auto');
-SELECT pg_catalog.citus_move_shard_placement(85674055,61,63,'auto');
-SELECT pg_catalog.citus_move_shard_placement(85674056,61,63,'auto');
-
-- now create another rebalance strategy in order to simulate moves
-- which use as target a node that has been previously used as source
-CREATE OR REPLACE FUNCTION test_shard_allowed_on_node(shardid bigint, nodeid int)
-    RETURNS boolean AS
-$$
-    -- analogous to '{"node_name": "hostname1", "disallowed_shards": "1,2,3,5,6"}'
-    select case when (shardid != 85674054 and nodeid = 61)
-        then false
-    -- analogous to '{"node_name": "hostname2", "disallowed_shards": "4"}'
-    --          AND '{"node_name": "hostname2", "disallowed_shards": "4"}'
-    when (shardid = 85674054 and nodeid != 61)
-        then false
-    else true
-    end;
-$$ LANGUAGE sql;
-
-- insert the new test rebalance strategy
-INSERT INTO
-    pg_catalog.pg_dist_rebalance_strategy(
-        name,
-        default_strategy,
-        shard_cost_function,
-        node_capacity_function,
-        shard_allowed_on_node_function,
-        default_threshold,
-        minimum_threshold,
-        improvement_threshold
-    ) VALUES (
-        'test_source_then_target',
-        false,
-        'citus_shard_cost_1',
-        'citus_node_capacity_1',
-        'background_rebalance_parallel.test_shard_allowed_on_node',
-        0,
-        0,
-        0
-    );
-
-SELECT * FROM get_rebalance_table_shards_plan(rebalance_strategy := 'test_source_then_target');
-
-SELECT citus_rebalance_start AS job_id from citus_rebalance_start(rebalance_strategy := 'test_source_then_target') \gset
-
-- check that the third move is blocked and depends on the first two
-SELECT job_id, task_id, status, nodes_involved
-FROM pg_dist_background_task WHERE job_id in (:job_id) ORDER BY task_id;
-
-SELECT D.task_id,
-       (SELECT T.command FROM pg_dist_background_task T WHERE T.task_id = D.task_id),
-       D.depends_on,
-       (SELECT T.command FROM pg_dist_background_task T WHERE T.task_id = D.depends_on)
-FROM pg_dist_background_task_depend D  WHERE job_id in (:job_id) ORDER BY D.task_id, D.depends_on ASC;
-
-SELECT citus_rebalance_stop();
-DELETE FROM pg_catalog.pg_dist_rebalance_strategy WHERE name='test_source_then_target';
-
-DROP SCHEMA background_rebalance_parallel CASCADE;
-TRUNCATE pg_dist_background_job CASCADE;
-TRUNCATE pg_dist_background_task CASCADE;
-TRUNCATE pg_dist_background_task_depend;
-SELECT public.wait_for_resource_cleanup();
-select citus_remove_node('localhost', :worker_3_port);
 -- keep the rest of the tests inact that depends node/group ids
 ALTER SEQUENCE pg_catalog.pg_dist_groupid_seq RESTART :last_group_id_cls;
 ALTER SEQUENCE pg_catalog.pg_dist_node_nodeid_seq RESTART :last_node_id_cls;
--- a/src/test/regress/sql/background_task_queue_monitor.sql
+++ b/src/test/regress/sql/background_task_queue_monitor.sql
@ -3,7 +3,6 @@ SET search_path TO background_task_queue_monitor;
 SET citus.shard_count TO 4;
 SET citus.shard_replication_factor TO 1;
 SET citus.next_shard_id TO 3536400;
-SET client_min_messages TO ERROR;

 -- reset sequence values
 ALTER SEQUENCE pg_dist_background_job_job_id_seq RESTART 1450000;
@ -280,106 +279,11 @@ SELECT job_id, task_id, status FROM pg_dist_background_task
    WHERE task_id IN (:task_id1, :task_id2)
    ORDER BY job_id, task_id;  -- show that task is cancelled

-- TEST11
-- verify that we do not allow parallel task executors involving a particular node
-- more than citus.max_background_task_executors_per_node
-- verify that we can change citus.max_background_task_executors_per_node on the fly
-- tests are done with dummy node ids
-- citus_task_wait calls are used to ensure consistent pg_dist_background_task query
-- output i.e. to avoid flakiness
-
-BEGIN;
-INSERT INTO pg_dist_background_job (job_type, description) VALUES ('test_job', 'simple test to verify changing max background task executors per node on the fly') RETURNING job_id AS job_id1 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(2); $job$, ARRAY [1, 2]) RETURNING task_id AS task_id1 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(2); $job$, ARRAY [3, 4]) RETURNING task_id AS task_id2 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(4); $job$, ARRAY [1, 2]) RETURNING task_id AS task_id3 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(4); $job$, ARRAY [1, 3]) RETURNING task_id AS task_id4 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(4); $job$, ARRAY [2, 4]) RETURNING task_id AS task_id5 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(7); $job$, ARRAY [1, 2]) RETURNING task_id AS task_id6 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(6); $job$, ARRAY [1, 3]) RETURNING task_id AS task_id7 \gset
-INSERT INTO pg_dist_background_task (job_id, command, nodes_involved) VALUES (:job_id1, $job$ SELECT pg_sleep(6); $job$, ARRAY [1, 4]) RETURNING task_id AS task_id8 \gset
-COMMIT;
-
-SELECT citus_task_wait(:task_id1, desired_status => 'running');
-SELECT citus_task_wait(:task_id2, desired_status => 'running');
-
-SELECT job_id, task_id, status, nodes_involved FROM pg_dist_background_task
-    WHERE task_id IN (:task_id1, :task_id2, :task_id3, :task_id4,
-                      :task_id5, :task_id6, :task_id7, :task_id8)
-    ORDER BY job_id, task_id; -- show that at most 1 task per node is running
-
-SELECT citus_task_wait(:task_id1, desired_status => 'done');
-SELECT citus_task_wait(:task_id2, desired_status => 'done');
-- increase max_background_task_executors_per_node on the fly
-ALTER SYSTEM SET citus.max_background_task_executors_per_node = 2;
-SELECT pg_reload_conf();
-
-SELECT citus_task_wait(:task_id3, desired_status => 'running');
-SELECT citus_task_wait(:task_id4, desired_status => 'running');
-SELECT citus_task_wait(:task_id5, desired_status => 'running');
-
-SELECT job_id, task_id, status, nodes_involved FROM pg_dist_background_task
-    WHERE task_id IN (:task_id1, :task_id2, :task_id3, :task_id4,
-                      :task_id5, :task_id6, :task_id7, :task_id8)
-    ORDER BY job_id, task_id; -- show that at most 2 tasks per node are running
-
-- increase to 3 max_background_task_executors_per_node on the fly
-SELECT citus_task_wait(:task_id3, desired_status => 'done');
-SELECT citus_task_wait(:task_id4, desired_status => 'done');
-SELECT citus_task_wait(:task_id5, desired_status => 'done');
-ALTER SYSTEM SET citus.max_background_task_executors_per_node = 3;
-SELECT pg_reload_conf();
-
-SELECT citus_task_wait(:task_id6, desired_status => 'running');
-SELECT citus_task_wait(:task_id7, desired_status => 'running');
-SELECT citus_task_wait(:task_id8, desired_status => 'running');
-
-SELECT job_id, task_id, status, nodes_involved FROM pg_dist_background_task
-    WHERE task_id IN (:task_id1, :task_id2, :task_id3, :task_id4,
-                      :task_id5, :task_id6, :task_id7, :task_id8)
-    ORDER BY job_id, task_id; -- show that at most 3 tasks per node are running
-
-ALTER SYSTEM RESET citus.max_background_task_executors_per_node;
-SELECT pg_reload_conf();
-
-- if pg_cancel_backend is called on one of the running task PIDs
-- task doesn't restart because it's not allowed anymore by the limit.
-- node with id 1 can be used only once, unless there are previously running tasks
-SELECT pid AS task_id6_pid FROM pg_dist_background_task WHERE task_id IN (:task_id6) \gset
-SELECT pg_cancel_backend(:task_id6_pid); -- cancel task_id6 process
-
-- task goes to only runnable state, not running anymore.
-SELECT citus_task_wait(:task_id6, desired_status => 'runnable');
-
-- show that cancelled task hasn't restarted because limit doesn't allow it
-SELECT job_id, task_id, status, nodes_involved FROM pg_dist_background_task
-    WHERE task_id IN (:task_id1, :task_id2, :task_id3, :task_id4,
-                      :task_id5, :task_id6, :task_id7, :task_id8)
-    ORDER BY job_id, task_id;
-
-SELECT citus_task_wait(:task_id7, desired_status => 'done');
-SELECT citus_task_wait(:task_id8, desired_status => 'done');
-SELECT citus_task_wait(:task_id6, desired_status => 'running');
-
-- show that the 6th task has restarted only after both 6 and 7 are done
-- since we have a limit of 1 background task executor per node with id 1
-SELECT job_id, task_id, status, nodes_involved FROM pg_dist_background_task
-    WHERE task_id IN (:task_id1, :task_id2, :task_id3, :task_id4,
-                      :task_id5, :task_id6, :task_id7, :task_id8)
-    ORDER BY job_id, task_id;
-
-SELECT citus_job_cancel(:job_id1);
-SELECT citus_job_wait(:job_id1);
-
-ALTER SYSTEM RESET citus.max_background_task_executors_per_node;
-SELECT pg_reload_conf();
-
 SET client_min_messages TO WARNING;
 TRUNCATE pg_dist_background_job CASCADE;
 TRUNCATE pg_dist_background_task CASCADE;
 TRUNCATE pg_dist_background_task_depend;
 DROP SCHEMA background_task_queue_monitor CASCADE;
-RESET client_min_messages;

 ALTER SYSTEM RESET citus.background_task_queue_interval;
 ALTER SYSTEM RESET citus.max_background_task_executors;
--- a/src/test/regress/sql/multi_extension.sql
+++ b/src/test/regress/sql/multi_extension.sql
@ -529,13 +529,33 @@ SELECT * FROM multi_extension.print_extension_changes();

 -- Test downgrade to 11.1-1 from 11.2-1
 ALTER EXTENSION citus UPDATE TO '11.2-1';
+
+-- create a table with orphaned shards to see if orphaned shards will be dropped
+-- and cleanup records will be created for them
+SET citus.shard_replication_factor to 1;
+CREATE TABLE table_with_orphaned_shards (a int);
+SELECT create_distributed_table('table_with_orphaned_shards', 'a');
+-- show there are 4 placements
+SELECT * FROM pg_dist_placement ORDER BY shardid;
+-- mark two of them as orphaned
+UPDATE pg_dist_placement SET shardstate = 4 WHERE shardid % 2 = 1;
+
 ALTER EXTENSION citus UPDATE TO '11.1-1';
+
+-- show placements and cleanup records
+SELECT * FROM pg_dist_placement ORDER BY shardid;
+SELECT * FROM pg_dist_cleanup;
+
 -- Should be empty result since upgrade+downgrade should be a no-op
 SELECT * FROM multi_extension.print_extension_changes();

 -- Snapshot of state at 11.2-1
 ALTER EXTENSION citus UPDATE TO '11.2-1';

+-- verify that the placements are deleted and cleanup records are created
+SELECT * FROM pg_dist_placement ORDER BY shardid;
+SELECT * FROM pg_dist_cleanup;
+
 ALTER EXTENSION citus_columnar UPDATE TO '11.2-1';

 -- Make sure that we defined dependencies from all rel objects (tables,
@ -569,21 +589,20 @@ SELECT COUNT(*)=5 FROM columnar_schema_members_pg_depend;

 DROP TABLE columnar_schema_members, columnar_schema_members_pg_depend;

+-- error out as cleanup records remain
+ALTER EXTENSION citus UPDATE TO '11.0-4';
+
+-- cleanup
+SET client_min_messages TO ERROR;
+CALL citus_cleanup_orphaned_resources();
+DROP TABLE table_with_orphaned_shards;
+RESET client_min_messages;
+
 SELECT * FROM multi_extension.print_extension_changes();

-- Test downgrade to 11.2-1 from 11.2-2
-ALTER EXTENSION citus UPDATE TO '11.2-2';
-ALTER EXTENSION citus UPDATE TO '11.2-1';
-- Should be empty result since upgrade+downgrade should be a no-op
-SELECT * FROM multi_extension.print_extension_changes();
-
-- Snapshot of state at 11.2-2
-ALTER EXTENSION citus UPDATE TO '11.2-2';
-SELECT * FROM multi_extension.print_extension_changes();
-
-- Test downgrade to 11.2-2 from 11.3-1
+-- Test downgrade to 11.2-1 from 11.3-1
 ALTER EXTENSION citus UPDATE TO '11.3-1';
-ALTER EXTENSION citus UPDATE TO '11.2-2';
+ALTER EXTENSION citus UPDATE TO '11.2-1';
 -- Should be empty result since upgrade+downgrade should be a no-op
 SELECT * FROM multi_extension.print_extension_changes();

--- a/src/test/regress/sql/multi_metadata_attributes.sql
+++ b/src/test/regress/sql/multi_metadata_attributes.sql
@ -10,6 +10,5 @@ FROM pg_attribute
 WHERE atthasmissing AND attrelid NOT IN ('pg_dist_node'::regclass,
                                         'pg_dist_rebalance_strategy'::regclass,
                                         'pg_dist_partition'::regclass,
-                                         'pg_dist_object'::regclass,
-                                         'pg_dist_background_task'::regclass)
+                                         'pg_dist_object'::regclass)
 ORDER BY attrelid, attname;
--- a/src/test/regress/sql/multi_metadata_sync.sql
+++ b/src/test/regress/sql/multi_metadata_sync.sql
@ -111,7 +111,7 @@ SELECT nodeid, hasmetadata FROM pg_dist_node WHERE nodename='localhost' AND node
 \c - - - :worker_1_port
 SELECT * FROM pg_dist_local_group;
 SELECT * FROM pg_dist_node ORDER BY nodeid;
-SELECT * FROM pg_dist_partition WHERE logicalrelid::text LIKE 'mx_testing_schema%' ORDER BY logicalrelid::text;
+SELECT * FROM pg_dist_partition WHERE logicalrelid::text LIKE 'mx_testing_schema%' ORDER BY logicalrelid;
 SELECT * FROM pg_dist_shard  WHERE logicalrelid::text LIKE 'mx_testing_schema%' ORDER BY shardid;
 SELECT * FROM pg_dist_shard_placement WHERE shardid IN (SELECT shardid FROM pg_dist_shard WHERE logicalrelid::text LIKE 'mx_testing_schema%') ORDER BY shardid, nodename, nodeport;
 SELECT "Column", "Type", "Modifiers" FROM table_desc WHERE relid='mx_testing_schema.mx_test_table'::regclass;
@ -161,7 +161,7 @@ SELECT 1 FROM citus_activate_node('localhost', :worker_1_port);
 \c - - - :worker_1_port
 SELECT * FROM pg_dist_local_group;
 SELECT * FROM pg_dist_node ORDER BY nodeid;
-SELECT * FROM pg_dist_partition WHERE logicalrelid::text LIKE 'mx_testing_schema%' ORDER BY logicalrelid::text;
+SELECT * FROM pg_dist_partition WHERE logicalrelid::text LIKE 'mx_testing_schema%' ORDER BY logicalrelid;
 SELECT * FROM pg_dist_shard WHERE logicalrelid::text LIKE 'mx_testing_schema%' ORDER BY shardid;
 SELECT * FROM pg_dist_shard_placement WHERE shardid IN (SELECT shardid FROM pg_dist_shard WHERE logicalrelid::text LIKE 'mx_testing_schema%') ORDER BY shardid, nodename, nodeport;
 SELECT "Column", "Type", "Modifiers" FROM table_desc WHERE relid='mx_testing_schema.mx_test_table'::regclass;
@ -252,7 +252,7 @@ WHERE
 	logicalrelid = 'mx_test_schema_1.mx_table_1'::regclass
 	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass
 ORDER BY
-	logicalrelid::text;
+	logicalrelid;

 -- See the shards and placements of the mx tables
 SELECT
@ -263,7 +263,7 @@ WHERE
 	logicalrelid = 'mx_test_schema_1.mx_table_1'::regclass
 	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass
 ORDER BY
-	logicalrelid::text, shardid;
+	logicalrelid, shardid;

 -- Check that metadata of MX tables exist on the metadata worker
 \c - - - :worker_1_port
@ -278,9 +278,7 @@ FROM
 	pg_dist_partition
 WHERE
 	logicalrelid = 'mx_test_schema_1.mx_table_1'::regclass
-	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass
-ORDER BY
-	logicalrelid::text;
+	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass;

 -- Check that shard and placement data are created
 SELECT
@ -291,7 +289,7 @@ WHERE
 	logicalrelid = 'mx_test_schema_1.mx_table_1'::regclass
 	OR logicalrelid = 'mx_test_schema_2.mx_table_2'::regclass
 ORDER BY
-	logicalrelid::text, shardid;
+	logicalrelid, shardid;

 -- Check that metadata of MX tables don't exist on the non-metadata worker
 \c - - - :worker_2_port
@ -383,7 +381,7 @@ FROM
 WHERE
 	logicalrelid = 'mx_colocation_test_1'::regclass
 	OR logicalrelid = 'mx_colocation_test_2'::regclass
-ORDER BY logicalrelid::text;
+ORDER BY logicalrelid;

 -- Update colocation and see the changes on the master and the worker
 SELECT update_distributed_table_colocation('mx_colocation_test_1', colocate_with => 'mx_colocation_test_2');
@ -393,9 +391,7 @@ FROM
 	pg_dist_partition
 WHERE
 	logicalrelid = 'mx_colocation_test_1'::regclass
-	OR logicalrelid = 'mx_colocation_test_2'::regclass
-ORDER BY
-	logicalrelid::text;
+	OR logicalrelid = 'mx_colocation_test_2'::regclass;
 \c - - - :worker_1_port
 SELECT
 	logicalrelid, colocationid
@ -403,9 +399,7 @@ FROM
 	pg_dist_partition
 WHERE
 	logicalrelid = 'mx_colocation_test_1'::regclass
-	OR logicalrelid = 'mx_colocation_test_2'::regclass
-ORDER BY
-	logicalrelid::text;
+	OR logicalrelid = 'mx_colocation_test_2'::regclass;

 \c - - - :master_port

--- a/src/test/regress/sql/upgrade_basic_after.sql
+++ b/src/test/regress/sql/upgrade_basic_after.sql
@ -8,21 +8,8 @@ SELECT nextval('pg_dist_placement_placementid_seq') = MAX(placementid)+1 FROM pg
 SELECT nextval('pg_dist_groupid_seq') = MAX(groupid)+1 FROM pg_dist_node;
 SELECT nextval('pg_dist_node_nodeid_seq') = MAX(nodeid)+1 FROM pg_dist_node;
 SELECT nextval('pg_dist_colocationid_seq') = MAX(colocationid)+1 FROM pg_dist_colocation;
-- while testing sequences on pg_dist_cleanup, they return null in pg upgrade schedule
-- but return a valid value in citus upgrade schedule
-- that's why we accept both NULL and MAX()+1 here
-SELECT
-    CASE WHEN MAX(operation_id) IS NULL
-    THEN true
-    ELSE nextval('pg_dist_operationid_seq') = MAX(operation_id)+1
-    END AS check_operationid
-    FROM pg_dist_cleanup;
-SELECT
-    CASE WHEN MAX(record_id) IS NULL
-    THEN true
-    ELSE nextval('pg_dist_cleanup_recordid_seq') = MAX(record_id)+1
-    END AS check_recordid
-    FROM pg_dist_cleanup;
+SELECT nextval('pg_dist_operationid_seq') = MAX(operation_id)+1 FROM pg_dist_cleanup;
+SELECT nextval('pg_dist_cleanup_recordid_seq') = MAX(record_id)+1 FROM pg_dist_cleanup;
 SELECT nextval('pg_dist_background_job_job_id_seq') > COALESCE(MAX(job_id), 0) FROM pg_dist_background_job;
 SELECT nextval('pg_dist_background_task_task_id_seq') > COALESCE(MAX(task_id), 0) FROM pg_dist_background_task;
 SELECT last_value > 0 FROM pg_dist_clock_logical_seq;
--- a/src/test/regress/sql/upgrade_pg_dist_cleanup_after.sql
+++ b/src/test/regress/sql/upgrade_pg_dist_cleanup_after.sql
@ -1,15 +0,0 @@
-\set upgrade_test_old_citus_version `echo "$CITUS_OLD_VERSION"`
-SELECT substring(:'upgrade_test_old_citus_version', 'v(\d+)\.\d+\.\d+')::int > 11 OR
-       (substring(:'upgrade_test_old_citus_version', 'v(\d+)\.\d+\.\d+')::int = 11 AND
-        substring(:'upgrade_test_old_citus_version', 'v\d+\.(\d+)\.\d+')::int >= 2)
-AS upgrade_test_old_citus_version_gte_11_2;
-\gset
-\if :upgrade_test_old_citus_version_gte_11_2
-\q
-\endif
-
-- verify that the orphaned placement is deleted and cleanup record is created
-SELECT COUNT(*) FROM pg_dist_placement WHERE shardid IN (SELECT shardid FROM pg_dist_shard WHERE logicalrelid='table_with_orphaned_shards'::regclass);
-SELECT * FROM pg_dist_cleanup;
-CALL citus_cleanup_orphaned_resources();
-DROP TABLE table_with_orphaned_shards;
--- a/src/test/regress/sql/upgrade_pg_dist_cleanup_before.sql
+++ b/src/test/regress/sql/upgrade_pg_dist_cleanup_before.sql
@ -1,22 +0,0 @@
-\set upgrade_test_old_citus_version `echo "$CITUS_OLD_VERSION"`
-SELECT substring(:'upgrade_test_old_citus_version', 'v(\d+)\.\d+\.\d+')::int > 11 OR
-       (substring(:'upgrade_test_old_citus_version', 'v(\d+)\.\d+\.\d+')::int = 11 AND
-        substring(:'upgrade_test_old_citus_version', 'v\d+\.(\d+)\.\d+')::int >= 2)
-AS upgrade_test_old_citus_version_gte_11_2;
-\gset
-\if :upgrade_test_old_citus_version_gte_11_2
-\q
-\endif
-
-- create a table with orphaned shards to see if orphaned shards will be dropped
-- and cleanup records will be created for them
-SET citus.next_shard_id TO 980000;
-CREATE TABLE table_with_orphaned_shards (a int);
-SELECT create_distributed_table('table_with_orphaned_shards', 'a');
-- show all 32 placements are active
-SELECT COUNT(*) FROM pg_dist_placement WHERE shardstate = 1 AND shardid IN (SELECT shardid FROM pg_dist_shard WHERE logicalrelid='table_with_orphaned_shards'::regclass);
-- create an orphaned placement based on an existing one
-INSERT INTO pg_dist_placement(placementid, shardid, shardstate, shardlength, groupid)
-    SELECT nextval('pg_dist_placement_placementid_seq'::regclass), shardid, 4, shardlength, 3-groupid
-    FROM pg_dist_placement
-    WHERE shardid = 980001;