testCreateShrinkIndex should make sure to use the right source stats when testing shrunk target

core/src/test/java/org/elasticsearch/action/admin/indices/create/ShrinkIndexIT.java

@@ -35,12 +35,15 @@ import org.elasticsearch.action.index.IndexRequest;
 import org.elasticsearch.action.support.ActiveShardCount;
 import org.elasticsearch.client.Client;
 import org.elasticsearch.cluster.ClusterInfoService;
+import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.InternalClusterInfoService;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.cluster.routing.Murmur3HashFunction;
 import org.elasticsearch.cluster.routing.RoutingTable;
+import org.elasticsearch.cluster.routing.ShardRouting;
 import org.elasticsearch.cluster.routing.UnassignedInfo;
+import org.elasticsearch.cluster.routing.allocation.decider.EnableAllocationDecider;
 import org.elasticsearch.common.Priority;
 import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.common.settings.Settings;
@@ -60,6 +63,7 @@ import org.elasticsearch.test.VersionUtils;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
+import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
@@ -239,7 +243,6 @@ public class ShrinkIndexIT extends ESIntegTestCase {
                 client().admin().cluster().prepareState().get().getState().nodes().getDataNodes();
         assertTrue("at least 2 nodes but was: " + dataNodes.size(), dataNodes.size() >= 2);
         DiscoveryNode[] discoveryNodes = dataNodes.values().toArray(DiscoveryNode.class);
-        String mergeNode = discoveryNodes[0].getName();
         // ensure all shards are allocated otherwise the ensure green below might not succeed since we require the merge node
         // if we change the setting too quickly we will end up with one replica unassigned which can't be assigned anymore due
         // to the require._name below.
@@ -247,33 +250,53 @@ public class ShrinkIndexIT extends ESIntegTestCase {
         // relocate all shards to one node such that we can merge it.
         client().admin().indices().prepareUpdateSettings("source")
             .setSettings(Settings.builder()
-                .put("index.routing.allocation.require._name", mergeNode)
+                .put("index.routing.allocation.require._name", discoveryNodes[0].getName())
                 .put("index.blocks.write", true)).get();
         ensureGreen();
 
         final IndicesStatsResponse sourceStats = client().admin().indices().prepareStats("source").setSegments(true).get();
-        final long maxSeqNo =
-                Arrays.stream(sourceStats.getShards()).map(ShardStats::getSeqNoStats).mapToLong(SeqNoStats::getMaxSeqNo).max().getAsLong();
-        final long maxUnsafeAutoIdTimestamp =
-                Arrays.stream(sourceStats.getShards())
-                        .map(ShardStats::getStats)
-                        .map(CommonStats::getSegments)
-                        .mapToLong(SegmentsStats::getMaxUnsafeAutoIdTimestamp)
-                        .max()
-                        .getAsLong();
-        // now merge source into a single shard index
 
+        // disable rebalancing to be able to capture the right stats. balancing can move the target primary
+        // making it hard to pin point the source shards.
+        client().admin().cluster().prepareUpdateSettings().setTransientSettings(Settings.builder().put(
+            EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), "none"
+        )).get();
+
+
+        // now merge source into a single shard index
         final boolean createWithReplicas = randomBoolean();
         assertAcked(client().admin().indices().prepareShrinkIndex("source", "target")
             .setSettings(Settings.builder().put("index.number_of_replicas", createWithReplicas ? 1 : 0).build()).get());
         ensureGreen();
 
+        // resolve true merge node - this is not always the node we required as all shards may be on another node
+        final ClusterState state = client().admin().cluster().prepareState().get().getState();
+        DiscoveryNode mergeNode = state.nodes().get(state.getRoutingTable().index("target").shard(0).primaryShard().currentNodeId());
+        logger.info("merge node {}", mergeNode);
+
+        final long maxSeqNo = Arrays.stream(sourceStats.getShards())
+            .filter(shard -> shard.getShardRouting().currentNodeId().equals(mergeNode.getId()))
+            .map(ShardStats::getSeqNoStats).mapToLong(SeqNoStats::getMaxSeqNo).max().getAsLong();
+        final long maxUnsafeAutoIdTimestamp = Arrays.stream(sourceStats.getShards())
+            .filter(shard -> shard.getShardRouting().currentNodeId().equals(mergeNode.getId()))
+            .map(ShardStats::getStats)
+            .map(CommonStats::getSegments)
+            .mapToLong(SegmentsStats::getMaxUnsafeAutoIdTimestamp)
+            .max()
+            .getAsLong();
+
+        for (ShardStats shard: Arrays.stream(sourceStats.getShards()).filter(shard -> shard.getShardRouting().currentNodeId().equals(mergeNode.getId())).collect(Collectors.toList())) {
+            logger.info("used {}, timestamp: {}", shard.getShardRouting(), shard.getStats().getSegments().getMaxUnsafeAutoIdTimestamp());
+        }
+
         final IndicesStatsResponse targetStats = client().admin().indices().prepareStats("target").get();
         for (final ShardStats shardStats : targetStats.getShards()) {
             final SeqNoStats seqNoStats = shardStats.getSeqNoStats();
-            assertThat(seqNoStats.getMaxSeqNo(), equalTo(maxSeqNo));
+            final ShardRouting shardRouting = shardStats.getShardRouting();
-            assertThat(seqNoStats.getLocalCheckpoint(), equalTo(maxSeqNo));
+            assertThat("failed on " + shardRouting, seqNoStats.getMaxSeqNo(), equalTo(maxSeqNo));
-            assertThat(shardStats.getStats().getSegments().getMaxUnsafeAutoIdTimestamp(), equalTo(maxUnsafeAutoIdTimestamp));
+            assertThat("failed on " + shardRouting, seqNoStats.getLocalCheckpoint(), equalTo(maxSeqNo));
+            assertThat("failed on " + shardRouting,
+                shardStats.getStats().getSegments().getMaxUnsafeAutoIdTimestamp(), equalTo(maxUnsafeAutoIdTimestamp));
         }
 
         final int size = docs > 0 ? 2 * docs : 1;
@@ -297,6 +320,11 @@ public class ShrinkIndexIT extends ESIntegTestCase {
         assertHitCount(client().prepareSearch("source").setSize(size).setQuery(new TermsQueryBuilder("foo", "bar")).get(), docs);
         GetSettingsResponse target = client().admin().indices().prepareGetSettings("target").get();
         assertEquals(version, target.getIndexToSettings().get("target").getAsVersion("index.version.created", null));
+
+        // clean up
+        client().admin().cluster().prepareUpdateSettings().setTransientSettings(Settings.builder().put(
+            EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), (String)null
+        )).get();
     }
     /**
      * Tests that we can manually recover from a failed allocation due to shards being moved away etc.