From 59117125b4312f2534656d2510742227249366a5 Mon Sep 17 00:00:00 2001
From: Boaz Leskes <b.leskes@gmail.com>
Date: Sun, 9 Nov 2014 21:57:25 +0100
Subject: [PATCH] Internal: extend refresh-mapping logic to the _default_ type

When data nodes receive mapping updates from the master, the parse it and merge it into their own in memory representation (if there). If this results in different bytes then the master sent, the nodes will send a refresh-mapping command to indicate to the master that it's byte level storage of the mapping should be refreshed via the document mappers. This comes handy when the mapping format has changed, in a backwards compatible manner, and we want to make sure we can still rely on the bytes to identify changes.  An example of such a change can be seen at #4760.

This commit extends the logic to include the `_default_` type, which was never refreshed before. In some unlucky scenarios, this caused the _default_ mapping to be parsed with every cluster state update.

Closes #8413
---
 .../cluster/IndicesClusterStateService.java   | 27 ++++++++++---------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/src/main/java/org/elasticsearch/indices/cluster/IndicesClusterStateService.java b/src/main/java/org/elasticsearch/indices/cluster/IndicesClusterStateService.java
index c7acfd96e04..48e6c620d34 100644
--- a/src/main/java/org/elasticsearch/indices/cluster/IndicesClusterStateService.java
+++ b/src/main/java/org/elasticsearch/indices/cluster/IndicesClusterStateService.java
@@ -67,7 +67,10 @@ import org.elasticsearch.indices.recovery.RecoveryState;
 import org.elasticsearch.indices.recovery.RecoveryTarget;
 import org.elasticsearch.threadpool.ThreadPool;
 
-import java.util.*;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.atomic.AtomicLong;
 
@@ -340,7 +343,7 @@ public class IndicesClusterStateService extends AbstractLifecycleComponent<Indic
                 // we only create / update here
                 continue;
             }
-            List<String> typesToRefresh = null;
+            List<String> typesToRefresh = Lists.newArrayList();
             String index = indexMetaData.index();
             IndexService indexService = indicesService.indexService(index);
             if (indexService == null) {
@@ -350,7 +353,10 @@ public class IndicesClusterStateService extends AbstractLifecycleComponent<Indic
             MapperService mapperService = indexService.mapperService();
             // first, go over and update the _default_ mapping (if exists)
             if (indexMetaData.mappings().containsKey(MapperService.DEFAULT_MAPPING)) {
-                processMapping(index, mapperService, MapperService.DEFAULT_MAPPING, indexMetaData.mapping(MapperService.DEFAULT_MAPPING).source());
+                boolean requireRefresh = processMapping(index, mapperService, MapperService.DEFAULT_MAPPING, indexMetaData.mapping(MapperService.DEFAULT_MAPPING).source());
+                if (requireRefresh) {
+                    typesToRefresh.add(MapperService.DEFAULT_MAPPING);
+                }
             }
 
             // go over and add the relevant mappings (or update them)
@@ -363,19 +369,14 @@ public class IndicesClusterStateService extends AbstractLifecycleComponent<Indic
                 }
                 boolean requireRefresh = processMapping(index, mapperService, mappingType, mappingSource);
                 if (requireRefresh) {
-                    if (typesToRefresh == null) {
-                        typesToRefresh = Lists.newArrayList();
-                    }
                     typesToRefresh.add(mappingType);
                 }
             }
-            if (typesToRefresh != null) {
-                if (sendRefreshMapping) {
-                    nodeMappingRefreshAction.nodeMappingRefresh(event.state(),
-                            new NodeMappingRefreshAction.NodeMappingRefreshRequest(index, indexMetaData.uuid(),
-                                    typesToRefresh.toArray(new String[typesToRefresh.size()]), event.state().nodes().localNodeId())
-                    );
-                }
+            if (!typesToRefresh.isEmpty() && sendRefreshMapping) {
+                nodeMappingRefreshAction.nodeMappingRefresh(event.state(),
+                        new NodeMappingRefreshAction.NodeMappingRefreshRequest(index, indexMetaData.uuid(),
+                                typesToRefresh.toArray(new String[typesToRefresh.size()]), event.state().nodes().localNodeId())
+                );
             }
             // go over and remove mappings
             for (DocumentMapper documentMapper : mapperService.docMappers(true)) {