YARN-236. RM should point tracking URL to RM web page when app fails to start (Jason Lowe via jeagles)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1448406 13f79535-47bb-0310-9956-ffa450edef68

hadoop-yarn-project/CHANGES.txt

@@ -316,6 +316,9 @@ Release 0.23.7 - UNRELEASED
     YARN-249. Capacity Scheduler web page should show list of active users per 
     queue like it used to (in 1.x) (Ravi Prakash via tgraves)
 
+    YARN-236. RM should point tracking URL to RM web page when app fails to
+    start (Jason Lowe via jeagles)
+
   OPTIMIZATIONS
 
     YARN-357. App submission should not be synchronized (daryn)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-web-proxy/src/main/java/org/apache/hadoop/yarn/server/webproxy/WebAppProxyServlet.java

@@ -66,6 +66,7 @@ public class WebAppProxyServlet extends HttpServlet {
   public static final String PROXY_USER_COOKIE_NAME = "proxy-user";
 
   private final List<TrackingUriPlugin> trackingUriPlugins;
+  private final String rmAppPageUrlBase;
 
   private static class _ implements Hamlet._ {
     //Empty
@@ -91,6 +92,8 @@ public class WebAppProxyServlet extends HttpServlet {
     this.trackingUriPlugins =
         conf.getInstances(YarnConfiguration.YARN_TRACKING_URL_GENERATOR,
             TrackingUriPlugin.class);
+    this.rmAppPageUrlBase = StringHelper.pjoin(
+        YarnConfiguration.getRMWebAppURL(conf), "cluster", "app");
   }
 
   /**
@@ -291,25 +294,10 @@ public class WebAppProxyServlet extends HttpServlet {
       if (original != null) {
         trackingUri = ProxyUriUtils.getUriFromAMUrl(original);
       }
+      // fallback to ResourceManager's app page if no tracking URI provided
       if(original == null || original.equals("N/A")) {
-        String message;
-        switch(applicationReport.getFinalApplicationStatus()) {
-          case FAILED:
-          case KILLED:
-          case SUCCEEDED:
-            message =
-              "The requested application exited before setting a tracking URL.";
-            break;
-          case UNDEFINED:
-            message = "The requested application does not appear to be running "
-              +"yet, and has not set a tracking URL.";
-            break;
-          default:
-            //This should never happen, but just to be safe
-            message = "The requested application has not set a tracking URL.";
-            break;
-        }
-        notFound(resp, message);
+        resp.sendRedirect(resp.encodeRedirectURL(
+            StringHelper.pjoin(rmAppPageUrlBase, id.toString())));
         return;
       }