[SPARK-10148] [STREAMING] Display active and inactive receiver numbers in Streaming page

Added the active and inactive receiver numbers in the summary section of Streaming page.

<img width="1074" alt="screen shot 2015-08-21 at 2 08 54 pm" src="https://cloud.githubusercontent.com/assets/1000778/9402437/ff2806a2-480f-11e5-8f8e-efdf8e5d514d.png">

Author: zsxwing <zsxwing@gmail.com>

Closes #8351 from zsxwing/receiver-number.

(cherry picked from commit c6df5f66d9a8b9760f2cd46fcd930f977650c9c5)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>

2 files changed, 14 insertions, 0 deletions

diff --git a/streaming/src/main/scala/org/apache/spark/streaming/ui/StreamingJobProgressListener.scala b/streaming/src/main/scala/org/apache/spark/streaming/ui/StreamingJobProgressListener.scala
index b77c555c68..78aeb004e1 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/ui/StreamingJobProgressListener.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/ui/StreamingJobProgressListener.scala
@@ -148,6 +148,14 @@ private[streaming] class StreamingJobProgressListener(ssc: StreamingContext)
     receiverInfos.size
   }
 
+  def numActiveReceivers: Int = synchronized {
+    receiverInfos.count(_._2.active)
+  }
+
+  def numInactiveReceivers: Int = {
+    ssc.graph.getReceiverInputStreams().size - numActiveReceivers
+  }
+
   def numTotalCompletedBatches: Long = synchronized {
     totalCompletedBatches
   }
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/ui/StreamingPage.scala b/streaming/src/main/scala/org/apache/spark/streaming/ui/StreamingPage.scala
index 87af902428..96d943e75d 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/ui/StreamingPage.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/ui/StreamingPage.scala
@@ -303,6 +303,7 @@ private[ui] class StreamingPage(parent: StreamingTab)
 
     val numCompletedBatches = listener.retainedCompletedBatches.size
     val numActiveBatches = batchTimes.length - numCompletedBatches
+    val numReceivers = listener.numInactiveReceivers + listener.numActiveReceivers
     val table =
       // scalastyle:off
       <table id="stat-table" class="table table-bordered" style="width: auto">
@@ -330,6 +331,11 @@ private[ui] class StreamingPage(parent: StreamingTab)
                 }
               }
               </div>
+              {
+                if (numReceivers > 0) {
+                  <div>Receivers: {listener.numActiveReceivers} / {numReceivers} active</div>
+                }
+              }
               <div>Avg: {eventRateForAllStreams.formattedAvg} events/sec</div>
             </div>
           </td>