From b6e6a8c090590aaa77fa5816014a62ee8565af63 Mon Sep 17 00:00:00 2001
From: Tim Brooks <tim@uncontended.net>
Date: Wed, 17 Jun 2020 08:01:35 -0600
Subject: [PATCH] Fix replication operation transient retry test (#58205)

After the work to retry transient replication failures, the local and
global checkpoint test metadata can be incremented on a different thread
than the test thread. This appears to introduce an extremely rare
scenario where this data is not visible for later test assertions. This
commit fixes the issue by using synchronized maps.
---
 .../action/support/replication/ReplicationOperationTests.java | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/server/src/test/java/org/elasticsearch/action/support/replication/ReplicationOperationTests.java b/server/src/test/java/org/elasticsearch/action/support/replication/ReplicationOperationTests.java
index 45778056337..1c072fa0784 100644
--- a/server/src/test/java/org/elasticsearch/action/support/replication/ReplicationOperationTests.java
+++ b/server/src/test/java/org/elasticsearch/action/support/replication/ReplicationOperationTests.java
@@ -561,8 +561,8 @@ public class ReplicationOperationTests extends ESTestCase {
         final long maxSeqNoOfUpdatesOrDeletes;
         final Supplier<ReplicationGroup> replicationGroupSupplier;
         final PendingReplicationActions pendingReplicationActions;
-        final Map<String, Long> knownLocalCheckpoints = new HashMap<>();
-        final Map<String, Long> knownGlobalCheckpoints = new HashMap<>();
+        final Map<String, Long> knownLocalCheckpoints = Collections.synchronizedMap(new HashMap<>());
+        final Map<String, Long> knownGlobalCheckpoints = Collections.synchronizedMap(new HashMap<>());
 
         TestPrimary(ShardRouting routing, Supplier<ReplicationGroup> replicationGroupSupplier, ThreadPool threadPool) {
             this.routing = routing;