From f1f54e0f6137e55c403da2bb25e27b98c38f2ade Mon Sep 17 00:00:00 2001
From: Tanguy Leroux <tlrx.dev@gmail.com>
Date: Fri, 25 Jan 2019 16:31:26 +0100
Subject: [PATCH] TransportUnfollowAction should increase settings version
 (#37859)

The TransportUnfollowAction updates the index settings but does not
increase the settings version to reflect that change.

This issue has been caught while working on the replication of closed
indices (#33888). The IndexFollowingIT.testUnfollowIndex() started to
fail and this specific assertion tripped. It does not happen on master
branch today because index metadata for closed indices are never
updated in IndexService instances, but this is something that is going
to change with the replication of closed indices.
---
 .../xpack/ccr/action/TransportUnfollowAction.java        | 9 +++++----
 .../xpack/ccr/action/TransportUnfollowActionTests.java   | 3 +++
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/action/TransportUnfollowAction.java b/x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/action/TransportUnfollowAction.java
index a42ff658dc9..3a158aceddb 100644
--- a/x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/action/TransportUnfollowAction.java
+++ b/x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/action/TransportUnfollowAction.java
@@ -105,18 +105,19 @@ public class TransportUnfollowAction extends TransportMasterNodeAction<UnfollowA
             }
         }
 
-        IndexMetaData.Builder newIMD = IndexMetaData.builder(followerIMD);
         // Remove index.xpack.ccr.following_index setting
         Settings.Builder builder = Settings.builder();
         builder.put(followerIMD.getSettings());
         builder.remove(CcrSettings.CCR_FOLLOWING_INDEX_SETTING.getKey());
 
-        newIMD.settings(builder);
+        final IndexMetaData.Builder newIndexMetaData = IndexMetaData.builder(followerIMD);
+        newIndexMetaData.settings(builder);
+        newIndexMetaData.settingsVersion(followerIMD.getSettingsVersion() + 1);
         // Remove ccr custom metadata
-        newIMD.removeCustom(Ccr.CCR_CUSTOM_METADATA_KEY);
+        newIndexMetaData.removeCustom(Ccr.CCR_CUSTOM_METADATA_KEY);
 
         MetaData newMetaData = MetaData.builder(current.metaData())
-            .put(newIMD)
+            .put(newIndexMetaData)
             .build();
         return ClusterState.builder(current)
             .metaData(newMetaData)
diff --git a/x-pack/plugin/ccr/src/test/java/org/elasticsearch/xpack/ccr/action/TransportUnfollowActionTests.java b/x-pack/plugin/ccr/src/test/java/org/elasticsearch/xpack/ccr/action/TransportUnfollowActionTests.java
index 9b9d088eea3..93987a7306f 100644
--- a/x-pack/plugin/ccr/src/test/java/org/elasticsearch/xpack/ccr/action/TransportUnfollowActionTests.java
+++ b/x-pack/plugin/ccr/src/test/java/org/elasticsearch/xpack/ccr/action/TransportUnfollowActionTests.java
@@ -30,8 +30,10 @@ import static org.hamcrest.Matchers.nullValue;
 public class TransportUnfollowActionTests extends ESTestCase {
 
     public void testUnfollow() {
+        final long settingsVersion = randomNonNegativeLong();
         IndexMetaData.Builder followerIndex = IndexMetaData.builder("follow_index")
             .settings(settings(Version.CURRENT).put(CcrSettings.CCR_FOLLOWING_INDEX_SETTING.getKey(), true))
+            .settingsVersion(settingsVersion)
             .numberOfShards(1)
             .numberOfReplicas(0)
             .state(IndexMetaData.State.CLOSE)
@@ -47,6 +49,7 @@ public class TransportUnfollowActionTests extends ESTestCase {
         IndexMetaData resultIMD = result.metaData().index("follow_index");
         assertThat(resultIMD.getSettings().get(CcrSettings.CCR_FOLLOWING_INDEX_SETTING.getKey()), nullValue());
         assertThat(resultIMD.getCustomData(Ccr.CCR_CUSTOM_METADATA_KEY), nullValue());
+        assertThat(resultIMD.getSettingsVersion(), equalTo(settingsVersion + 1));
     }
 
     public void testUnfollowIndexOpen() {