From 56ab64b747c415b6942b9a1de6e103af5f817a0a Mon Sep 17 00:00:00 2001
From: Gledis Zeneli <43916939+gledis69@users.noreply.github.com>
Date: Tue, 15 Mar 2022 15:02:47 +0300
Subject: [PATCH] Patches #5758 with some more error checks (#5804)

Add error checks to detect failed connection and don't ping secondary nodes to detect self reference.
---
 src/backend/distributed/metadata/node_metadata.c         | 1 +
 src/backend/distributed/transaction/worker_transaction.c | 9 ++++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/distributed/metadata/node_metadata.c b/src/backend/distributed/metadata/node_metadata.c
index 6f80558e8..214fb2dec 100644
--- a/src/backend/distributed/metadata/node_metadata.c
+++ b/src/backend/distributed/metadata/node_metadata.c
@@ -283,6 +283,7 @@ citus_add_node(PG_FUNCTION_ARGS)
 		 */
 		if (workerNode != NULL &&
 			workerNode->groupId != COORDINATOR_GROUP_ID &&
+			workerNode->nodeRole != SecondaryNodeRoleId() &&
 			IsWorkerTheCurrentNode(workerNode))
 		{
 			ereport(ERROR, (errmsg("Node cannot add itself as a worker."),
diff --git a/src/backend/distributed/transaction/worker_transaction.c b/src/backend/distributed/transaction/worker_transaction.c
index 44e4a1ead..69a318023 100644
--- a/src/backend/distributed/transaction/worker_transaction.c
+++ b/src/backend/distributed/transaction/worker_transaction.c
@@ -658,10 +658,17 @@ IsWorkerTheCurrentNode(WorkerNode *workerNode)
 									  workerNode->workerPort,
 									  CurrentUserName(),
 									  NULL);
+
 	const char *command =
 		"SELECT metadata ->> 'server_id' AS server_id FROM pg_dist_node_metadata";
 
-	SendRemoteCommand(workerConnection, command);
+	int resultCode = SendRemoteCommand(workerConnection, command);
+
+	if (resultCode == 0)
+	{
+		CloseConnection(workerConnection);
+		return false;
+	}
 
 	PGresult *result = GetRemoteCommandResult(workerConnection, true);