[TEST] Ensure that all flushes happen on PeerRecovery tests

src/test/java/org/elasticsearch/gateway/local/SimpleRecoveryLocalGatewayTests.java

@@ -34,7 +34,6 @@ import org.elasticsearch.indices.recovery.RecoveryState;
 import org.elasticsearch.test.ElasticsearchIntegrationTest;
 import org.elasticsearch.test.ElasticsearchIntegrationTest.ClusterScope;
 import org.elasticsearch.test.InternalTestCluster.RestartCallback;
-import org.elasticsearch.test.junit.annotations.TestLogging;
 import org.elasticsearch.test.store.MockDirectoryHelper;
 import org.elasticsearch.test.store.MockFSDirectoryService;
 import org.junit.Test;
@@ -363,10 +362,13 @@ public class SimpleRecoveryLocalGatewayTests extends ElasticsearchIntegrationTes
                 client().admin().indices().prepareFlush().execute().actionGet();
             }
         }
-        client().admin().indices().prepareFlush().execute().actionGet();
-
+        if (randomBoolean()) {
+            client().admin().indices().prepareFlush().execute().actionGet();
+        }
         logger.info("Running Cluster Health");
         ensureGreen();
+        client().admin().indices().prepareOptimize("test").setWaitForMerge(true).setMaxNumSegments(100).get(); // just wait for merges
+        client().admin().indices().prepareFlush().setWaitIfOngoing(true).setForce(true).execute().actionGet();
 
         logger.info("--> shutting down the nodes");