From 205501532a59c0bf746e6518b6842882e26a3c71 Mon Sep 17 00:00:00 2001
From: Onder Kalaci <onder@citusdata.com>
Date: Mon, 14 Aug 2017 15:46:18 +0300
Subject: [PATCH] Add version check to the maintenance daemon

We should prevent running the deadlock detection if
there is a major version change. Otherwise, the daemon
may access to obsolete metadata catalog tables.
---
 src/backend/distributed/utils/maintenanced.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/backend/distributed/utils/maintenanced.c b/src/backend/distributed/utils/maintenanced.c
index 2bf847455..fe33c7a26 100644
--- a/src/backend/distributed/utils/maintenanced.c
+++ b/src/backend/distributed/utils/maintenanced.c
@@ -266,7 +266,16 @@ CitusMaintenanceDaemonMain(Datum main_arg)
 		if (DistributedDeadlockDetectionTimeoutFactor != -1.0)
 		{
 			StartTransactionCommand();
-			foundDeadlock = CheckForDistributedDeadlocks();
+
+			/*
+			 * We don't want to run the deadlock checks if there exists
+			 * any version mistmatch.
+			 */
+			if (CheckCitusVersion(DEBUG1))
+			{
+				foundDeadlock = CheckForDistributedDeadlocks();
+			}
+
 			CommitTransactionCommand();
 
 			/*