HDFS-17634. Add unit test

Author: Felix Nguyen

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/metrics/NamenodeBeanMetrics.java

@@ -25,6 +25,7 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Optional;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Function;
@@ -476,6 +477,7 @@ private String getNodesImpl(final DatanodeReportType type) {
         innerinfo.put("infoSecureAddr", node.getInfoSecureAddr());
         innerinfo.put("xferaddr", node.getXferAddr());
         innerinfo.put("location", node.getNetworkLocation());
+        innerinfo.put("uuid", Optional.ofNullable(node.getDatanodeUuid()).orElse(""));
         innerinfo.put("lastContact", getLastContact(node));
         innerinfo.put("usedSpace", node.getDfsUsed());
         innerinfo.put("adminState", node.getAdminState().toString());

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterRpc.java

@@ -135,6 +135,8 @@
 import org.apache.hadoop.service.Service.STATE;
 import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.test.LambdaTestUtils;
+
+import org.codehaus.jettison.json.JSONArray;
 import org.codehaus.jettison.json.JSONException;
 import org.codehaus.jettison.json.JSONObject;
 import org.junit.After;
@@ -1880,6 +1882,22 @@ public void testNamenodeMetrics() throws Exception {
     JSONObject jsonObject = new JSONObject(jsonString0);
     assertEquals(NUM_SUBCLUSTERS * NUM_DNS, jsonObject.names().length());
 
+    JSONObject jsonObjectNn =
+        new JSONObject(cluster.getRandomNamenode().getNamenode().getNamesystem().getLiveNodes());
+    // DN report by NN and router should be the same
+    String randomDn = (String) jsonObjectNn.names().get(0);
+    JSONObject randomReportNn = jsonObjectNn.getJSONObject(randomDn);
+    JSONObject randomReportRouter = jsonObject.getJSONObject(randomDn);
+    JSONArray keys = randomReportNn.names();
+    for (int i = 0; i < keys.length(); i++) {
+      String key = keys.getString(i);
+      // Skip the 2 keys that always return -1
+      if (key.equals("blockScheduled") || key.equals("volfails")) {
+        continue;
+      }
+      assertEquals(randomReportRouter.get(key), randomReportNn.get(key));
+    }
+
     // We should be caching this information
     String jsonString1 = metrics.getLiveNodes();
     assertEquals(jsonString0, jsonString1);