YARN-1525. Web UI should redirect to active RM when HA is enabled. (Cindy Li via kasha)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1575167 13f79535-47bb-0310-9956-ffa450edef68

hadoop-yarn-project/CHANGES.txt

@@ -253,6 +253,9 @@ Release 2.4.0 - UNRELEASED
     YARN-1780. Improved logging in the Timeline client and server. (Zhijie Shen
     via vinodkv)
 
+    YARN-1525. Web UI should redirect to active RM when HA is enabled. (Cindy Li
+    via kasha)
+
   OPTIMIZATIONS
 
   BUG FIXES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/test/java/org/apache/hadoop/yarn/client/TestRMFailover.java

@@ -26,13 +26,14 @@ import static org.junit.Assert.fail;
 import java.io.IOException;
 import java.net.HttpURLConnection;
 import java.net.URL;
+import java.util.List;
+import java.util.Map;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.ha.ClientBaseWithFixes;
 import org.apache.hadoop.ha.HAServiceProtocol;
-import org.apache.hadoop.ha.proto.HAServiceProtocolProtos;
 import org.apache.hadoop.service.Service.STATE;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
 import org.apache.hadoop.yarn.client.api.YarnClient;
@@ -252,4 +253,37 @@ public class TestRMFailover extends ClientBaseWithFixes {
         .contains("Application with id '" + fakeAppId + "' " +
             "doesn't exist in RM."));
   }
+
+  @Test
+  public void testRMWebAppRedirect() throws YarnException,
+      InterruptedException, IOException {
+    cluster = new MiniYARNCluster(TestRMFailover.class.getName(), 2, 0, 1, 1);
+    conf.setBoolean(YarnConfiguration.AUTO_FAILOVER_ENABLED, false);
+
+    cluster.init(conf);
+    cluster.start();
+    getAdminService(0).transitionToActive(req);
+    String rm1Url = "http://0.0.0.0:18088";
+    String rm2Url = "http://0.0.0.0:28088";
+    String header = getHeader("Refresh", rm2Url);
+    assertTrue(header.contains("; url=" + rm1Url));
+
+    header = getHeader("Refresh", rm2Url + "/cluster/cluster");
+    assertEquals(null, header);
+
+    // Due to the limitation of MiniYARNCluster and dispatcher is a singleton,
+    // we couldn't add the test case after explicitFailover();
+  }
+
+  static String getHeader(String field, String url) {
+    String fieldHeader = null;
+    try {
+      Map<String, List<String>> map =
+          new URL(url).openConnection().getHeaderFields();
+      fieldHeader = map.get(field).get(0);
+    } catch (Exception e) {
+      // throw new RuntimeException(e);
+    }
+    return fieldHeader;
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/webapp/Dispatcher.java

@@ -57,11 +57,11 @@ public class Dispatcher extends HttpServlet {
 
   private transient final Injector injector;
   private transient final Router router;
-  private transient final WebApp webApp;
+  protected transient final WebApp webApp;
   private volatile boolean devMode = false;
 
   @Inject
-  Dispatcher(WebApp webApp, Injector injector, Router router) {
+  protected Dispatcher(WebApp webApp, Injector injector, Router router) {
     this.webApp = webApp;
     this.injector = injector;
     this.router = router;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/webapp/Router.java

@@ -44,7 +44,7 @@ import com.google.common.collect.Maps;
  * Manages path info to controller#action routing.
  */
 @InterfaceAudience.LimitedPrivate({"YARN", "MapReduce"})
-class Router {
+public class Router {
   static final Logger LOG = LoggerFactory.getLogger(Router.class);
   static final ImmutableList<String> EMPTY_LIST = ImmutableList.of();
   static final CharMatcher SLASH = CharMatcher.is('/');

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/webapp/WebApp.java

@@ -55,7 +55,7 @@ public abstract class WebApp extends ServletModule {
 
   private volatile String name;
   private volatile List<String> servePathSpecs = new ArrayList<String>();
-  // path to redirect to if user goes to "/"
+  // path to redirect to
   private volatile String redirectPath;
   private volatile String wsName;
   private volatile Configuration conf;
@@ -134,7 +134,9 @@ public abstract class WebApp extends ServletModule {
    * more easily differentiate the different webapps.
    * @param path  the path to redirect to
    */
-  void setRedirectPath(String path) { this.redirectPath = path; }
+  protected void setRedirectPath(String path) {
+    this.redirectPath = path;
+  }
 
   void setWebServices (String name) { this.wsName = name; }
 
@@ -158,6 +160,10 @@ public abstract class WebApp extends ServletModule {
       serve(path).with(Dispatcher.class);
     }
 
+    configureRSServlets();
+  }
+
+  protected void configureRSServlets() {
     // Add in the web services filters/serves if app has them.
     // Using Jersey/guice integration module. If user has web services
     // they must have also bound a default one in their webapp code.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/RMHAUtils.java

@@ -0,0 +1,70 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.yarn.server.resourcemanager;
+
+import java.util.Collection;
+
+import org.apache.hadoop.classification.InterfaceAudience.Private;
+import org.apache.hadoop.classification.InterfaceStability.Unstable;
+import org.apache.hadoop.fs.CommonConfigurationKeys;
+import org.apache.hadoop.ha.HAServiceProtocol;
+import org.apache.hadoop.ha.HAServiceProtocol.HAServiceState;
+import org.apache.hadoop.ha.HAServiceTarget;
+import org.apache.hadoop.yarn.client.RMHAServiceTarget;
+import org.apache.hadoop.yarn.conf.YarnConfiguration;
+
+@Private
+@Unstable
+public class RMHAUtils {
+
+  public static String findActiveRMHAId(YarnConfiguration conf) {
+    YarnConfiguration yarnConf = new YarnConfiguration(conf);
+    Collection<String> rmIds =
+        yarnConf.getStringCollection(YarnConfiguration.RM_HA_IDS);
+    for (String currentId : rmIds) {
+      yarnConf.set(YarnConfiguration.RM_HA_ID, currentId);
+      try {
+        HAServiceState haState = getHAState(yarnConf);
+        if (haState.equals(HAServiceState.ACTIVE)) {
+          return currentId;
+        }
+      } catch (Exception e) {
+        // Couldn't check if this RM is active. Do nothing. Worst case,
+        // we wouldn't find an Active RM and return null.
+      }
+    }
+    return null; // Couldn't find an Active RM
+  }
+
+  private static HAServiceState getHAState(YarnConfiguration yarnConf)
+      throws Exception {
+    HAServiceTarget haServiceTarget;
+    int rpcTimeoutForChecks =
+        yarnConf.getInt(CommonConfigurationKeys.HA_FC_CLI_CHECK_TIMEOUT_KEY,
+            CommonConfigurationKeys.HA_FC_CLI_CHECK_TIMEOUT_DEFAULT);
+
+    yarnConf.set(CommonConfigurationKeys.HADOOP_SECURITY_SERVICE_USER_NAME_KEY,
+        yarnConf.get(YarnConfiguration.RM_PRINCIPAL, ""));
+    haServiceTarget = new RMHAServiceTarget(yarnConf);
+    HAServiceProtocol proto =
+        haServiceTarget.getProxy(yarnConf, rpcTimeoutForChecks);
+    HAServiceState haState = proto.getServiceStatus().getState();
+    return haState;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMDispatcher.java

@@ -0,0 +1,79 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.yarn.server.resourcemanager.webapp;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.http.HtmlQuoting;
+import org.apache.hadoop.yarn.webapp.Dispatcher;
+import org.apache.hadoop.yarn.webapp.Router;
+import org.apache.hadoop.yarn.webapp.WebApp;
+
+import com.google.inject.Inject;
+import com.google.inject.Injector;
+import com.google.inject.Singleton;
+
+@InterfaceAudience.LimitedPrivate({ "YARN", "MapReduce" })
+@Singleton
+public class RMDispatcher extends Dispatcher {
+
+  /**
+   *
+   */
+  private static final long serialVersionUID = 1L;
+
+  @Inject
+  RMDispatcher(WebApp webApp, Injector injector, Router router) {
+    super(webApp, injector, router);
+  }
+
+  @Override
+  public void service(HttpServletRequest req, HttpServletResponse res)
+      throws ServletException, IOException {
+    res.setCharacterEncoding("UTF-8");
+    String uri = HtmlQuoting.quoteHtmlChars(req.getRequestURI());
+
+    if (uri == null) {
+      uri = "/";
+    }
+
+    RMWebApp rmWebApp = (RMWebApp) webApp;
+    rmWebApp.checkIfStandbyRM();
+    if (rmWebApp.isStandby()
+        && !uri.equals("/" + rmWebApp.name() + "/cluster")) {
+      String redirectPath = rmWebApp.getRedirectPath() + uri;
+      if (redirectPath != null && !redirectPath.isEmpty()) {
+        String redirectMsg =
+            "This is standby RM. Redirecting to the current active RM: "
+                + redirectPath;
+        res.addHeader("Refresh", "3; url=" + redirectPath);
+        PrintWriter out = res.getWriter();
+        out.println(redirectMsg);
+        return;
+      }
+    }
+    super.service(req, res);
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebApp.java

@@ -20,10 +20,16 @@ package org.apache.hadoop.yarn.server.resourcemanager.webapp;
 
 import static org.apache.hadoop.yarn.util.StringHelper.pajoin;
 
+import java.net.InetSocketAddress;
+
+import org.apache.hadoop.ha.HAServiceProtocol.HAServiceState;
+import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.server.resourcemanager.RMContext;
+import org.apache.hadoop.yarn.server.resourcemanager.RMHAUtils;
 import org.apache.hadoop.yarn.server.resourcemanager.ResourceManager;
 import org.apache.hadoop.yarn.server.resourcemanager.security.QueueACLsManager;
 import org.apache.hadoop.yarn.server.security.ApplicationACLsManager;
+import org.apache.hadoop.yarn.webapp.Dispatcher;
 import org.apache.hadoop.yarn.webapp.GenericExceptionHandler;
 import org.apache.hadoop.yarn.webapp.WebApp;
 import org.apache.hadoop.yarn.webapp.YarnWebParams;
@@ -34,6 +40,7 @@ import org.apache.hadoop.yarn.webapp.YarnWebParams;
 public class RMWebApp extends WebApp implements YarnWebParams {
 
   private final ResourceManager rm;
+  private boolean standby = false;
 
   public RMWebApp(ResourceManager rm) {
     this.rm = rm;
@@ -59,4 +66,59 @@ public class RMWebApp extends WebApp implements YarnWebParams {
     route("/scheduler", RmController.class, "scheduler");
     route(pajoin("/queue", QUEUE_NAME), RmController.class, "queue");
   }
+
+  @Override
+  public void configureServlets() {
+    setup();
+
+    serve("/").with(RMDispatcher.class);
+    serve("/__stop").with(Dispatcher.class);
+
+    for (String path : super.getServePathSpecs()) {
+      serve(path).with(RMDispatcher.class);
+    }
+
+    configureRSServlets();
+  }
+
+  public void checkIfStandbyRM() {
+    standby = (rm.getRMContext().getHAServiceState() == HAServiceState.STANDBY);
+  }
+
+  public boolean isStandby() {
+    return standby;
+  }
+
+  @Override
+  public String getRedirectPath() {
+    if (standby) {
+      return buildRedirectPath();
+    } else
+      return super.getRedirectPath();
+  }
+
+  private String buildRedirectPath() {
+    // make a copy of the original configuration so not to mutate it. Also use
+    // an YarnConfiguration to force loading of yarn-site.xml.
+    YarnConfiguration yarnConf = new YarnConfiguration(rm.getConfig());
+    String activeRMHAId = RMHAUtils.findActiveRMHAId(yarnConf);
+    String path = "";
+    if (activeRMHAId != null) {
+      yarnConf.set(YarnConfiguration.RM_HA_ID, activeRMHAId);
+
+      InetSocketAddress sock = YarnConfiguration.useHttps(yarnConf)
+          ? yarnConf.getSocketAddr(YarnConfiguration.RM_WEBAPP_HTTPS_ADDRESS,
+              YarnConfiguration.DEFAULT_RM_WEBAPP_HTTPS_ADDRESS,
+              YarnConfiguration.DEFAULT_RM_WEBAPP_HTTPS_PORT)
+          : yarnConf.getSocketAddr(YarnConfiguration.RM_WEBAPP_ADDRESS,
+              YarnConfiguration.DEFAULT_RM_WEBAPP_ADDRESS,
+              YarnConfiguration.DEFAULT_RM_WEBAPP_PORT);
+
+      path = sock.getHostName() + ":" + Integer.toString(sock.getPort());
+      path = YarnConfiguration.useHttps(yarnConf)
+          ? "https://" + path
+          : "http://" + path;
+    }
+    return path;
+  }
 }