HDFS-15613. RBF: Router FSCK fails after HDFS-14442. (#2360)

* Support getHAServiceState in DFSRouter

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

@@ -1799,10 +1799,11 @@ public class RouterClientProtocol implements ClientProtocol {
   }
 
   @Override
-  public HAServiceProtocol.HAServiceState getHAServiceState()
-      throws IOException {
-    rpcServer.checkOperation(NameNode.OperationCategory.READ, false);
-    return null;
+  public HAServiceProtocol.HAServiceState getHAServiceState() {
+    if (rpcServer.isSafeMode()) {
+      return HAServiceProtocol.HAServiceState.STANDBY;
+    }
+    return HAServiceProtocol.HAServiceState.ACTIVE;
   }
 
   /**

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

@@ -562,8 +562,7 @@ public class RouterRpcServer extends AbstractService implements ClientProtocol,
    *                          client requests.
    */
   private void checkSafeMode() throws StandbyException {
-    RouterSafemodeService safemodeService = router.getSafemodeService();
-    if (safemodeService != null && safemodeService.isInSafeMode()) {
+    if (isSafeMode()) {
       // Throw standby exception, router is not available
       if (rpcMonitor != null) {
         rpcMonitor.routerFailureSafemode();
@@ -574,6 +573,16 @@ public class RouterRpcServer extends AbstractService implements ClientProtocol,
     }
   }
 
+  /**
+   * Return true if the Router is in safe mode.
+   *
+   * @return true if the Router is in safe mode.
+   */
+  boolean isSafeMode() {
+    RouterSafemodeService safemodeService = router.getSafemodeService();
+    return (safemodeService != null && safemodeService.isInSafeMode());
+  }
+
   /**
    * Get the name of the method that is calling this function.
    *

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

@@ -1113,6 +1113,10 @@ public class TestRouterAdminCLI {
     // ensure the Router become RUNNING state
     waitState(RouterServiceState.RUNNING);
     assertFalse(routerContext.getRouter().getSafemodeService().isInSafeMode());
+    final RouterClientProtocol clientProtocol =
+        routerContext.getRouter().getRpcServer().getClientProtocolModule();
+    assertEquals(HAServiceState.ACTIVE, clientProtocol.getHAServiceState());
+
     assertEquals(0,
         ToolRunner.run(admin, new String[] {"-safemode", "enter" }));
 
@@ -1125,6 +1129,7 @@ public class TestRouterAdminCLI {
     // verify state using RBFMetrics
     assertEquals(RouterServiceState.SAFEMODE.toString(), jsonString);
     assertTrue(routerContext.getRouter().getSafemodeService().isInSafeMode());
+    assertEquals(HAServiceState.STANDBY, clientProtocol.getHAServiceState());
 
     System.setOut(new PrintStream(out));
     assertEquals(0,
@@ -1136,6 +1141,7 @@ public class TestRouterAdminCLI {
     // verify state
     assertEquals(RouterServiceState.RUNNING.toString(), jsonString);
     assertFalse(routerContext.getRouter().getSafemodeService().isInSafeMode());
+    assertEquals(HAServiceState.ACTIVE, clientProtocol.getHAServiceState());
 
     out.reset();
     assertEquals(0, ToolRunner.run(admin, new String[] {"-safemode", "get" }));