HDFS-13750. RBF: Router ID in RouterRpcClient is always null. Contributed by Takanobu Asanuma.

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterRpcClient.java

@@ -92,8 +92,8 @@ public class RouterRpcClient {
       LoggerFactory.getLogger(RouterRpcClient.class);
 
 
-  /** Router identifier. */
-  private final String routerId;
+  /** Router using this RPC client. */
+  private final Router router;
 
   /** Interface to identify the active NN for a nameservice or blockpool ID. */
   private final ActiveNamenodeResolver namenodeResolver;
@@ -116,12 +116,13 @@ public class RouterRpcClient {
    * Create a router RPC client to manage remote procedure calls to NNs.
    *
    * @param conf Hdfs Configuation.
+   * @param router A router using this RPC client.
    * @param resolver A NN resolver to determine the currently active NN in HA.
    * @param monitor Optional performance monitor.
    */
-  public RouterRpcClient(Configuration conf, String identifier,
+  public RouterRpcClient(Configuration conf, Router router,
       ActiveNamenodeResolver resolver, RouterRpcMonitor monitor) {
-    this.routerId = identifier;
+    this.router = router;
 
     this.namenodeResolver = resolver;
 
@@ -343,7 +344,8 @@ private Object invokeMethod(
 
     if (namenodes == null || namenodes.isEmpty()) {
       throw new IOException("No namenodes to invoke " + method.getName() +
-          " with params " + Arrays.toString(params) + " from " + this.routerId);
+          " with params " + Arrays.toString(params) + " from "
+          + router.getRouterId());
     }
 
     Object ret = null;
@@ -1126,7 +1128,7 @@ public Object call() throws Exception {
       String msg = "Not enough client threads " + active + "/" + total;
       LOG.error(msg);
       throw new StandbyException(
-          "Router " + routerId + " is overloaded: " + msg);
+          "Router " + router.getRouterId() + " is overloaded: " + msg);
     } catch (InterruptedException ex) {
       LOG.error("Unexpected error while invoking API: {}", ex.getMessage());
       throw new IOException(
@@ -1150,7 +1152,7 @@ private List<? extends FederationNamenodeContext> getNamenodesForNameservice(
 
     if (namenodes == null || namenodes.isEmpty()) {
       throw new IOException("Cannot locate a registered namenode for " + nsId +
-          " from " + this.routerId);
+          " from " + router.getRouterId());
     }
     return namenodes;
   }
@@ -1171,7 +1173,7 @@ private List<? extends FederationNamenodeContext> getNamenodesForBlockPoolId(
 
     if (namenodes == null || namenodes.isEmpty()) {
       throw new IOException("Cannot locate a registered namenode for " + bpId +
-          " from " + this.routerId);
+          " from " + router.getRouterId());
     }
     return namenodes;
   }

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterRpcServer.java

@@ -196,6 +196,7 @@ public class RouterRpcServer extends AbstractService
    * Construct a router RPC server.
    *
    * @param configuration HDFS Configuration.
+   * @param router A router using this RPC server.
    * @param nnResolver The NN resolver instance to determine active NNs in HA.
    * @param fileResolver File resolver to resolve file paths to subclusters.
    * @throws IOException If the RPC server could not be created.
@@ -291,7 +292,7 @@ public RouterRpcServer(Configuration configuration, Router router,
     this.rpcMonitor = ReflectionUtils.newInstance(rpcMonitorClass, conf);
 
     // Create the client
-    this.rpcClient = new RouterRpcClient(this.conf, this.router.getRouterId(),
+    this.rpcClient = new RouterRpcClient(this.conf, this.router,
         this.namenodeResolver, this.rpcMonitor);
 
     // Initialize modules

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

@@ -129,6 +129,9 @@ public void updateActiveNamenode(
     // Return a copy of the list because it is updated periodically
     List<? extends FederationNamenodeContext> namenodes =
         this.resolver.get(nameserviceId);
+    if (namenodes == null) {
+      namenodes = new ArrayList<>();
+    }
     return Collections.unmodifiableList(new ArrayList<>(namenodes));
   }
 

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

@@ -18,9 +18,11 @@
 package org.apache.hadoop.hdfs.server.federation.router;
 
 import static org.apache.hadoop.test.GenericTestUtils.assertExceptionContains;
+import static org.apache.hadoop.test.LambdaTestUtils.intercept;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.fail;
+import static org.mockito.Mockito.mock;
 
 import java.io.IOException;
 import java.net.InetSocketAddress;
@@ -185,4 +187,20 @@ public void testRouterRpcWithNoSubclusters() throws IOException {
     router.stop();
     router.close();
   }
+
+  @Test
+  public void testRouterIDInRouterRpcClient() throws Exception {
+
+    Router router = new Router();
+    router.init(new RouterConfigBuilder(conf).rpc().build());
+    router.setRouterId("Router-0");
+    RemoteMethod remoteMethod = mock(RemoteMethod.class);
+
+    intercept(IOException.class, "Router-0",
+        () -> router.getRpcServer().getRPCClient()
+            .invokeSingle("ns0", remoteMethod));
+
+    router.stop();
+    router.close();
+  }
 }