HDFS-15458. TestNameNodeRetryCacheMetrics fails intermittently (#2356). Contributed by Hui Fei.

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNameNodeRetryCacheMetrics.java

@@ -19,7 +19,6 @@ package org.apache.hadoop.hdfs.server.namenode;
 
 import java.io.IOException;
 
-import org.apache.hadoop.hdfs.DFSClient;
 import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.server.namenode.ha.HATestUtil;
@@ -53,13 +52,12 @@ public class TestNameNodeRetryCacheMetrics {
   private Configuration conf;
   private RetryCacheMetrics metrics;
 
-  private DFSClient client;
-
   /** Start a cluster */
   @Before
   public void setup() throws Exception {
     conf = new HdfsConfiguration();
     conf.setBoolean(DFS_NAMENODE_ENABLE_RETRY_CACHE_KEY, true);
+    conf.setBoolean(HdfsClientConfigKeys.Failover.RANDOM_ORDER, false);
     conf.setInt(HdfsClientConfigKeys.DFS_CLIENT_TEST_DROP_NAMENODE_RESPONSE_NUM_KEY, 2);
     cluster = new MiniDFSCluster.Builder(conf)
         .nnTopology(MiniDFSNNTopology.simpleHATopology()).numDataNodes(3)