Print a handy message (Open H2O Flow in your web browser) when the cl…

…uster

comes up like Sparkling Water does.

To prevent lots of messages crossing each other, don't print this until all
the nodes have checked in with the full cluster size.  The code used to
"finish" after the first node checked in with the full cluster size.
This should not make any difference to the user, both behaviors are correct.

h2o-hadoop/h2o-mapreduce-generic/src/main/java/water/hadoop/h2odriver.java

@@ -81,6 +81,9 @@ public class h2odriver extends Configured implements Tool {
   volatile boolean clusterHasNodeWithLocalhostIp = false;
   volatile boolean shutdownRequested = false;
   volatile AtomicInteger numNodesStarted = new AtomicInteger();
+  volatile AtomicInteger numNodesReportingFullCloudSize = new AtomicInteger();
+  volatile String clusterIp = null;
+  volatile int clusterPort = -1;
 
   public void setShutdownRequested() {
     shutdownRequested = true;
@@ -90,6 +93,16 @@ public boolean getShutdownRequested() {
     return shutdownRequested;
   }
 
+  public void setClusterIpPort(String ip, int port) {
+    clusterIp = ip;
+    clusterPort = port;
+  }
+
+  public String getClusterUrl() {
+    String scheme = (jksFileName == null) ? "http" : "https";
+    return scheme + "://" + clusterIp + ":" + clusterPort;
+  }
+
   public boolean usingYarn() {
     Class clazz = null;
     try {
@@ -263,11 +276,15 @@ else if (type == MapperToDriverMessage.TYPE_CLOUD_SIZE) {
             // Do this under a synchronized block to avoid getting multiple cluster ready notification files.
             synchronized (h2odriver.class) {
               if (! clusterIsUp) {
-                if (clusterReadyFileName != null) {
-                  createClusterReadyFile(msg.getEmbeddedWebServerIp(), msg.getEmbeddedWebServerPort());
-                  System.out.println("Cluster notification file (" + clusterReadyFileName + ") created.");
+                int n = numNodesReportingFullCloudSize.incrementAndGet();
+                if (n == numNodes) {
+                  if (clusterReadyFileName != null) {
+                    createClusterReadyFile(msg.getEmbeddedWebServerIp(), msg.getEmbeddedWebServerPort());
+                    System.out.println("Cluster notification file (" + clusterReadyFileName + ") created.");
+                  }
+                  setClusterIpPort(msg.getEmbeddedWebServerIp(), msg.getEmbeddedWebServerPort());
+                  clusterIsUp = true;
                 }
-                clusterIsUp = true;
               }
             }
           }
@@ -1138,12 +1155,16 @@ else if (rv != 0) {
       // status stuff in H2O has settled down.
       Thread.sleep(CLOUD_FORMATION_SETTLE_DOWN_SECONDS);
 
+      System.out.println("Open H2O Flow in your web browser: " + getClusterUrl());
       System.out.println("Disowning cluster and exiting.");
       Runtime.getRuntime().removeShutdownHook(ctrlc);
       return 0;
     }
 
     System.out.println("(Note: Use the -disown option to exit the driver after cluster formation)");
+    System.out.println("");
+    System.out.println("Open H2O Flow in your web browser: " + getClusterUrl());
+    System.out.println("");
     System.out.println("(Press Ctrl-C to kill the cluster)");
     System.out.println("Blocking until the H2O cluster shuts down...");
     waitForClusterToShutdown();