rename node/worker utilities

The names were not explicit about what they do, and we have many
misusages in the codebase, so they are renamed to be more explicit.

(cherry picked from commit 09962a7e2ff340705b6b193bbfececa2d48e0855)

src/backend/distributed/commands/dependencies.c

@@ -85,7 +85,7 @@ EnsureDependenciesExistOnAllNodes(const ObjectAddress *target)
 	 * either get it now, or get it in master_add_node after this transaction finishes and
 	 * the pg_dist_object record becomes visible.
 	 */
-	List *workerNodeList = ActivePrimaryWorkerNodeList(RowShareLock);
+	List *workerNodeList = ActivePrimaryNonCoordinatorNodeList(RowShareLock);
 
 	/*
 	 * right after we acquired the lock we mark our objects as distributed, these changes

src/backend/distributed/commands/function.c

@@ -1022,7 +1022,7 @@ EnsureSequentialModeForFunctionDDL(void)
 static void
 TriggerSyncMetadataToPrimaryNodes(void)
 {
-	List *workerList = ActivePrimaryWorkerNodeList(ShareLock);
+	List *workerList = ActivePrimaryNonCoordinatorNodeList(ShareLock);
 	bool triggerMetadataSync = false;
 
 	WorkerNode *workerNode = NULL;

src/backend/distributed/executor/intermediate_results.c

@@ -136,7 +136,7 @@ broadcast_intermediate_result(PG_FUNCTION_ARGS)
 	 */
 	UseCoordinatedTransaction();
 
-	List *nodeList = ActivePrimaryWorkerNodeList(NoLock);
+	List *nodeList = ActivePrimaryNonCoordinatorNodeList(NoLock);
 	EState *estate = CreateExecutorState();
 	RemoteFileDestReceiver *resultDest =
 		(RemoteFileDestReceiver *) CreateRemoteFileDestReceiver(resultIdString,

src/backend/distributed/executor/multi_server_executor.c

@@ -118,7 +118,7 @@ JobExecutorType(DistributedPlan *distributedPlan)
 	}
 	else
 	{
-		List *workerNodeList = ActiveReadableWorkerNodeList();
+		List *workerNodeList = ActiveReadableNonCoordinatorNodeList();
 		int workerNodeCount = list_length(workerNodeList);
 		int taskCount = list_length(job->taskList);
 		double tasksPerNode = taskCount / ((double) workerNodeCount);

src/backend/distributed/executor/multi_task_tracker_executor.c

@@ -209,7 +209,7 @@ MultiTaskTrackerExecute(Job *job)
 	 * assigning and checking the status of tasks. The second (temporary) hash
 	 * helps us in fetching results data from worker nodes to the master node.
 	 */
-	List *workerNodeList = ActivePrimaryWorkerNodeList(NoLock);
+	List *workerNodeList = ActivePrimaryNonCoordinatorNodeList(NoLock);
 	uint32 taskTrackerCount = (uint32) list_length(workerNodeList);
 
 	/* connect as the current user for running queries */

src/backend/distributed/metadata/metadata_sync.c

@@ -1254,7 +1254,7 @@ SchemaOwnerName(Oid objectId)
 static bool
 HasMetadataWorkers(void)
 {
-	List *workerNodeList = ActivePrimaryWorkerNodeList(NoLock);
+	List *workerNodeList = ActivePrimaryNonCoordinatorNodeList(NoLock);
 
 	WorkerNode *workerNode = NULL;
 	foreach_ptr(workerNode, workerNodeList)
@@ -1373,7 +1373,7 @@ SyncMetadataToNodes(void)
 		return METADATA_SYNC_FAILED_LOCK;
 	}
 
-	List *workerList = ActivePrimaryWorkerNodeList(NoLock);
+	List *workerList = ActivePrimaryNonCoordinatorNodeList(NoLock);
 	WorkerNode *workerNode = NULL;
 	foreach_ptr(workerNode, workerList)
 	{

src/backend/distributed/operations/citus_create_restore_point.c

@@ -117,7 +117,7 @@ OpenConnectionsToAllWorkerNodes(LOCKMODE lockMode)
 	List *connectionList = NIL;
 	int connectionFlags = FORCE_NEW_CONNECTION;
 
-	List *workerNodeList = ActivePrimaryWorkerNodeList(lockMode);
+	List *workerNodeList = ActivePrimaryNonCoordinatorNodeList(lockMode);
 
 	WorkerNode *workerNode = NULL;
 	foreach_ptr(workerNode, workerNodeList)

src/backend/distributed/operations/node_protocol.c

@@ -457,7 +457,7 @@ master_get_active_worker_nodes(PG_FUNCTION_ARGS)
 		MemoryContext oldContext = MemoryContextSwitchTo(
 			functionContext->multi_call_memory_ctx);
 
-		List *workerNodeList = ActiveReadableWorkerNodeList();
+		List *workerNodeList = ActiveReadableNonCoordinatorNodeList();
 		workerNodeCount = (uint32) list_length(workerNodeList);
 
 		functionContext->user_fctx = workerNodeList;

src/backend/distributed/operations/worker_node_manager.c

@@ -293,12 +293,13 @@ WorkerGetNodeWithName(const char *hostname)
 
 
 /*
- * ActivePrimaryWorkerNodeCount returns the number of groups with a primary in the cluster.
+ * ActivePrimaryNonCoordinatorNodeCount returns the number of groups with a primary in the cluster.
+ * This method excludes coordinator even if it is added as a worker to cluster.
  */
 uint32
-ActivePrimaryWorkerNodeCount(void)
+ActivePrimaryNonCoordinatorNodeCount(void)
 {
-	List *workerNodeList = ActivePrimaryWorkerNodeList(NoLock);
+	List *workerNodeList = ActivePrimaryNonCoordinatorNodeList(NoLock);
 	uint32 liveWorkerCount = list_length(workerNodeList);
 
 	return liveWorkerCount;
@@ -306,12 +307,13 @@ ActivePrimaryWorkerNodeCount(void)
 
 
 /*
- * ActiveReadableWorkerNodeCount returns the number of groups with a node we can read from.
+ * ActiveReadableNonCoordinatorNodeCount returns the number of groups with a node we can read from.
+ * This method excludes coordinator even if it is added as a worker.
  */
 uint32
-ActiveReadableWorkerNodeCount(void)
+ActiveReadableNonCoordinatorNodeCount(void)
 {
-	List *workerNodeList = ActiveReadableWorkerNodeList();
+	List *workerNodeList = ActiveReadableNonCoordinatorNodeList();
 	uint32 liveWorkerCount = list_length(workerNodeList);
 
 	return liveWorkerCount;
@@ -366,13 +368,14 @@ FilterActiveNodeListFunc(LOCKMODE lockMode, bool (*checkFunction)(WorkerNode *))
 
 
 /*
- * ActivePrimaryWorkerNodeList returns a list of all active primary worker nodes
+ * ActivePrimaryNonCoordinatorNodeList returns a list of all active primary worker nodes
  * in workerNodeHash. lockMode specifies which lock to use on pg_dist_node,
  * this is necessary when the caller wouldn't want nodes to be added concurrent
  * to their use of this list.
+ * This method excludes coordinator even if it is added as a worker to cluster.
  */
 List *
-ActivePrimaryWorkerNodeList(LOCKMODE lockMode)
+ActivePrimaryNonCoordinatorNodeList(LOCKMODE lockMode)
 {
 	EnsureModificationsCanRun();
 	return FilterActiveNodeListFunc(lockMode, NodeIsPrimaryWorker);
@@ -443,11 +446,11 @@ NodeCanHaveDistTablePlacements(WorkerNode *node)
 
 
 /*
- * ActiveReadableWorkerNodeList returns a list of all nodes in workerNodeHash
- * that are readable workers.
+ * ActiveReadableNonCoordinatorNodeList returns a list of all nodes in workerNodeHash
+ * that are readable nodes This method excludes coordinator.
  */
 List *
-ActiveReadableWorkerNodeList(void)
+ActiveReadableNonCoordinatorNodeList(void)
 {
 	return FilterActiveNodeListFunc(NoLock, NodeIsReadableWorker);
 }
@@ -456,6 +459,7 @@ ActiveReadableWorkerNodeList(void)
 /*
  * ActiveReadableNodeList returns a list of all nodes in workerNodeHash
  * that are readable workers.
+ * This method includes coordinator if it is added as a worker to the cluster.
  */
 List *
 ActiveReadableNodeList(void)
@@ -602,7 +606,7 @@ WorkerNodeCompare(const void *lhsKey, const void *rhsKey, Size keySize)
 WorkerNode *
 GetFirstPrimaryWorkerNode(void)
 {
-	List *workerNodeList = ActivePrimaryWorkerNodeList(NoLock);
+	List *workerNodeList = ActivePrimaryNonCoordinatorNodeList(NoLock);
 	WorkerNode *firstWorkerNode = NULL;
 	WorkerNode *workerNode = NULL;
 	foreach_ptr(workerNode, workerNodeList)

src/backend/distributed/planner/intermediate_result_pruning.c

@@ -151,7 +151,7 @@ RecordSubplanExecutionsOnNodes(HTAB *intermediateResultsHash,
 	List *usedSubPlanNodeList = distributedPlan->usedSubPlanNodeList;
 	List *subPlanList = distributedPlan->subPlanList;
 	ListCell *subPlanCell = NULL;
-	int workerNodeCount = ActiveReadableWorkerNodeCount();
+	int workerNodeCount = ActiveReadableNonCoordinatorNodeCount();
 
 	foreach(subPlanCell, usedSubPlanNodeList)
 	{
@@ -269,7 +269,7 @@ AppendAllAccessedWorkerNodes(IntermediateResultsHashEntry *entry,
 static void
 AppendAllWorkerNodes(IntermediateResultsHashEntry *entry)
 {
-	List *workerNodeList = ActiveReadableWorkerNodeList();
+	List *workerNodeList = ActiveReadableNonCoordinatorNodeList();
 
 	WorkerNode *workerNode = NULL;
 	foreach_ptr(workerNode, workerNodeList)

src/backend/distributed/planner/multi_physical_planner.c

@@ -2107,7 +2107,7 @@ BuildMapMergeJob(Query *jobQuery, List *dependentJobList, Var *partitionKey,
 static uint32
 HashPartitionCount(void)
 {
-	uint32 groupCount = ActiveReadableWorkerNodeCount();
+	uint32 groupCount = ActiveReadableNonCoordinatorNodeCount();
 	double maxReduceTasksPerNode = MaxRunningTasksPerNode / 2.0;
 
 	uint32 partitionCount = (uint32) rint(groupCount * maxReduceTasksPerNode);
@@ -5717,7 +5717,7 @@ AssignDualHashTaskList(List *taskList)
 	 * if subsequent jobs have a small number of tasks, we won't allocate the
 	 * tasks to the same worker repeatedly.
 	 */
-	List *workerNodeList = ActiveReadableWorkerNodeList();
+	List *workerNodeList = ActiveReadableNonCoordinatorNodeList();
 	uint32 workerNodeCount = (uint32) list_length(workerNodeList);
 	uint32 beginningNodeIndex = jobId % workerNodeCount;
 

src/backend/distributed/planner/multi_router_planner.c

@@ -2299,7 +2299,7 @@ CreateDummyPlacement(bool hasLocalRelation)
 		return CreateLocalDummyPlacement();
 	}
 
-	List *workerNodeList = ActiveReadableWorkerNodeList();
+	List *workerNodeList = ActiveReadableNonCoordinatorNodeList();
 	if (workerNodeList == NIL)
 	{
 		/*

src/backend/distributed/test/metadata_sync.c

@@ -75,7 +75,7 @@ wait_until_metadata_sync(PG_FUNCTION_ARGS)
 {
 	uint32 timeout = PG_GETARG_UINT32(0);
 
-	List *workerList = ActivePrimaryWorkerNodeList(NoLock);
+	List *workerList = ActivePrimaryNonCoordinatorNodeList(NoLock);
 	bool waitNotifications = false;
 
 	WorkerNode *workerNode = NULL;

src/backend/distributed/transaction/backend_data.c

@@ -217,7 +217,7 @@ Datum
 get_global_active_transactions(PG_FUNCTION_ARGS)
 {
 	TupleDesc tupleDescriptor = NULL;
-	List *workerNodeList = ActivePrimaryWorkerNodeList(NoLock);
+	List *workerNodeList = ActivePrimaryNonCoordinatorNodeList(NoLock);
 	List *connectionList = NIL;
 	StringInfo queryToSend = makeStringInfo();
 

src/backend/distributed/transaction/citus_dist_stat_activity.c

@@ -311,7 +311,7 @@ citus_worker_stat_activity(PG_FUNCTION_ARGS)
 static List *
 CitusStatActivity(const char *statQuery)
 {
-	List *workerNodeList = ActivePrimaryWorkerNodeList(NoLock);
+	List *workerNodeList = ActivePrimaryNonCoordinatorNodeList(NoLock);
 	List *connectionList = NIL;
 
 	/*
@@ -437,7 +437,7 @@ GetLocalNodeCitusDistStat(const char *statQuery)
 	int32 localGroupId = GetLocalGroupId();
 
 	/* get the current worker's node stats */
-	List *workerNodeList = ActivePrimaryWorkerNodeList(NoLock);
+	List *workerNodeList = ActivePrimaryNonCoordinatorNodeList(NoLock);
 	WorkerNode *workerNode = NULL;
 	foreach_ptr(workerNode, workerNodeList)
 	{

src/backend/distributed/transaction/worker_transaction.c

@@ -156,7 +156,7 @@ static void
 SendCommandListToAllWorkersInternal(List *commandList, bool failOnError, const
 									char *superuser)
 {
-	List *workerNodeList = ActivePrimaryWorkerNodeList(NoLock);
+	List *workerNodeList = ActivePrimaryNonCoordinatorNodeList(NoLock);
 
 	WorkerNode *workerNode = NULL;
 	foreach_ptr(workerNode, workerNodeList)
@@ -198,7 +198,7 @@ SendOptionalCommandListToAllWorkers(List *commandList, const char *superuser)
 List *
 TargetWorkerSetNodeList(TargetWorkerSet targetWorkerSet, LOCKMODE lockMode)
 {
-	List *workerNodeList = ActivePrimaryWorkerNodeList(lockMode);
+	List *workerNodeList = ActivePrimaryNonCoordinatorNodeList(lockMode);
 	List *result = NIL;
 
 	WorkerNode *workerNode = NULL;

src/backend/distributed/utils/resource_lock.c

@@ -230,7 +230,7 @@ LockShardListResourcesOnFirstWorker(LOCKMODE lockmode, List *shardIntervalList)
 static bool
 IsFirstWorkerNode()
 {
-	List *workerNodeList = ActivePrimaryWorkerNodeList(NoLock);
+	List *workerNodeList = ActivePrimaryNonCoordinatorNodeList(NoLock);
 
 	workerNodeList = SortList(workerNodeList, CompareWorkerNodes);
 

src/backend/distributed/utils/statistics_collection.c

@@ -96,7 +96,7 @@ CollectBasicUsageStatistics(void)
 		distTableOids = DistTableOidList();
 		roundedDistTableCount = NextPow2(list_length(distTableOids));
 		roundedClusterSize = NextPow2(DistributedTablesSize(distTableOids));
-		workerNodeCount = ActivePrimaryWorkerNodeCount();
+		workerNodeCount = ActivePrimaryNonCoordinatorNodeCount();
 		metadataJsonbDatum = DistNodeMetadata();
 		metadataJsonbStr = DatumGetCString(DirectFunctionCall1(jsonb_out,
 															   metadataJsonbDatum));

src/include/distributed/worker_manager.h

@@ -70,14 +70,14 @@ extern WorkerNode * WorkerGetRoundRobinCandidateNode(List *workerNodeList,
 													 uint64 shardId,
 													 uint32 placementIndex);
 extern WorkerNode * WorkerGetLocalFirstCandidateNode(List *currentNodeList);
-extern uint32 ActivePrimaryWorkerNodeCount(void);
-extern List * ActivePrimaryWorkerNodeList(LOCKMODE lockMode);
+extern uint32 ActivePrimaryNonCoordinatorNodeCount(void);
+extern List * ActivePrimaryNonCoordinatorNodeList(LOCKMODE lockMode);
 extern List * ActivePrimaryNodeList(LOCKMODE lockMode);
 extern List * ReferenceTablePlacementNodeList(LOCKMODE lockMode);
 extern List * DistributedTablePlacementNodeList(LOCKMODE lockMode);
 extern bool NodeCanHaveDistTablePlacements(WorkerNode *node);
-extern uint32 ActiveReadableWorkerNodeCount(void);
-extern List * ActiveReadableWorkerNodeList(void);
+extern uint32 ActiveReadableNonCoordinatorNodeCount(void);
+extern List * ActiveReadableNonCoordinatorNodeList(void);
 extern List * ActiveReadableNodeList(void);
 extern WorkerNode * FindWorkerNode(const char *nodeName, int32 nodePort);
 extern WorkerNode * ForceFindWorkerNode(const char *nodeName, int32 nodePort);