HBASE-18789 Displays the reporting interval of each RS on the Master page

Signed-off-by: tedyu <yuzhihong@gmail.com>

hbase-client/src/main/java/org/apache/hadoop/hbase/ServerLoad.java

@@ -54,10 +54,12 @@ public class ServerLoad {
   private int totalStaticBloomSizeKB = 0;
   private long totalCompactingKVs = 0;
   private long currentCompactedKVs = 0;
+  private long reportTime = 0;
 
   @InterfaceAudience.Private
   public ServerLoad(ClusterStatusProtos.ServerLoad serverLoad) {
     this.serverLoad = serverLoad;
+    this.reportTime = System.currentTimeMillis();
     for (ClusterStatusProtos.RegionLoad rl: serverLoad.getRegionLoadsList()) {
       stores += rl.getStores();
       storefiles += rl.getStorefiles();
@@ -74,7 +76,6 @@ public class ServerLoad {
       totalCompactingKVs += rl.getTotalCompactingKVs();
       currentCompactedKVs += rl.getCurrentCompactedKVs();
     }
-
   }
 
   // NOTE: Function name cannot start with "get" because then an OpenDataException is thrown because
@@ -359,4 +360,8 @@ public class ServerLoad {
 
   public static final ServerLoad EMPTY_SERVERLOAD =
     new ServerLoad(ClusterStatusProtos.ServerLoad.newBuilder().build());
+
+  public long getReportTime() {
+    return reportTime;
+  }
 }

hbase-server/src/main/jamon/org/apache/hadoop/hbase/tmpl/master/RegionServerListTmpl.jamon

@@ -77,6 +77,7 @@ Arrays.sort(serverNames);
 <tr>
     <th>ServerName</th>
     <th>Start time</th>
+    <th>Last contact</th>
     <th>Version</th>
     <th>Requests Per Second</th>
     <th>Num. Regions</th>
@@ -96,6 +97,7 @@ Arrays.sort(serverNames);
     
     double requestsPerSecond = 0.0;
     int numRegionsOnline = 0;
+    long lastContact = 0;
 
     if (sl != null) {
         requestsPerSecond = sl.getRequestsPerSecond();
@@ -103,12 +105,14 @@ Arrays.sort(serverNames);
         totalRegions += sl.getNumberOfRegions();
         // Is this correct?  Adding a rate to a measure.
         totalRequests += sl.getNumberOfRequests();
+        lastContact = (System.currentTimeMillis() - sl.getReportTime())/1000;
     }
     long startcode = serverName.getStartcode();
 </%java>
 <tr>
     <td><& serverNameLink; serverName=serverName; serverLoad = sl; &></td>
     <td><% new Date(startcode) %></td>
+    <td><% TraditionalBinaryPrefix.long2String(lastContact, "s", 1) %></td>
     <td><% version %></td>
     <td><% String.format("%.0f", requestsPerSecond) %></td>
     <td><% numRegionsOnline %></td>
@@ -118,6 +122,7 @@ Arrays.sort(serverNames);
 </%java>
 <tr><td>Total:<% servers.size() %></td>
 <td></td>
+<td></td>
 <%if inconsistentNodeNum > 0%>
   <td style="color:red;"><% inconsistentNodeNum %> nodes with inconsistent version</td>
 <%else>