From da115151a54c7e5568267813464fbbf7395287bc Mon Sep 17 00:00:00 2001
From: Jason Tedor <jason@tedor.me>
Date: Fri, 17 Nov 2017 13:33:58 -0500
Subject: [PATCH] Log primary-replica resync failures

Today we do not fail a replica shard if the primary-replica resync to
that replica fails. Yet, we should at least log the failure
messages. This commit causes this to be the case.

Relates #27421
---
 .../resync/TransportResyncReplicationAction.java      | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/core/src/main/java/org/elasticsearch/action/resync/TransportResyncReplicationAction.java b/core/src/main/java/org/elasticsearch/action/resync/TransportResyncReplicationAction.java
index d217717faeb..32614c636f1 100644
--- a/core/src/main/java/org/elasticsearch/action/resync/TransportResyncReplicationAction.java
+++ b/core/src/main/java/org/elasticsearch/action/resync/TransportResyncReplicationAction.java
@@ -18,11 +18,13 @@
  */
 package org.elasticsearch.action.resync;
 
+import org.apache.logging.log4j.message.ParameterizedMessage;
 import org.elasticsearch.Version;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.support.ActionFilters;
 import org.elasticsearch.action.support.TransportActions;
 import org.elasticsearch.action.support.replication.ReplicationOperation;
+import org.elasticsearch.action.support.replication.ReplicationResponse;
 import org.elasticsearch.action.support.replication.TransportReplicationAction;
 import org.elasticsearch.action.support.replication.TransportWriteAction;
 import org.elasticsearch.cluster.action.shard.ShardStateAction;
@@ -158,6 +160,15 @@ public class TransportResyncReplicationAction extends TransportWriteAction<Resyn
 
                 @Override
                 public void handleResponse(ResyncReplicationResponse response) {
+                    final ReplicationResponse.ShardInfo.Failure[] failures = response.getShardInfo().getFailures();
+                    // noinspection ForLoopReplaceableByForEach
+                    for (int i = 0; i < failures.length; i++) {
+                        final ReplicationResponse.ShardInfo.Failure f = failures[i];
+                        logger.info(
+                                new ParameterizedMessage(
+                                        "{} primary-replica resync to replica on node [{}] failed", f.fullShardId(), f.nodeId()),
+                                f.getCause());
+                    }
                     listener.onResponse(response);
                 }