Logging: shard store shouldn't log the entire cluster state under trace, but just its version.

If we want the entire CS, we can put the cluster.service on trace

core/src/main/java/org/elasticsearch/action/admin/indices/shards/TransportIndicesShardStoresAction.java

@@ -83,7 +83,7 @@ public class TransportIndicesShardStoresAction extends TransportMasterNodeReadAc
         final String[] concreteIndices = indexNameExpressionResolver.concreteIndices(state, request);
         final Set<ShardId> shardIdsToFetch = new HashSet<>();
 
-        logger.trace("cluster state used to determine shards [{}]", state.prettyPrint());
+        logger.trace("using cluster state version [{}] to determine shards", state.version());
         // collect relevant shard ids of the requested indices for fetching store infos
         for (String index : concreteIndices) {
             IndexRoutingTable indexShardRoutingTables = routingTables.index(index);

core/src/test/java/org/elasticsearch/action/admin/indices/segments/IndicesShardStoreRequestTests.java

@@ -58,7 +58,7 @@ public class IndicesShardStoreRequestTests extends ElasticsearchIntegrationTest
     }
 
     @Test
-    @TestLogging("action.admin.indices.shards:TRACE")
+    @TestLogging("action.admin.indices.shards:TRACE,cluster.service:TRACE")
     public void testBasic() throws Exception {
         String index = "test";
         internalCluster().ensureAtLeastNumDataNodes(2);