adding spark.streaming.blockInterval property

docs/configuration.md

@@ -253,6 +253,13 @@ Apart from these, the following properties are also available, and may be useful
     applications). Note that any RDD that persists in memory for more than this duration will be cleared as well.
   </td>
 </tr>
+<tr>
+  <td>spark.streaming.blockInterval</td>
+  <td>200</td>
+  <td>
+    Duration (milliseconds) of how long to batch new objects coming from network receivers.
+  </td>
+</tr>
 
 </table>
 

streaming/src/main/scala/spark/streaming/dstream/NetworkInputDStream.scala

@@ -198,7 +198,7 @@ abstract class NetworkReceiver[T: ClassManifest]() extends Serializable with Log
     case class Block(id: String, iterator: Iterator[T], metadata: Any = null)
 
     val clock = new SystemClock()
-    val blockInterval = 200L
+    val blockInterval = System.getProperty("spark.streaming.blockInterval", "200").toLong
     val blockIntervalTimer = new RecurringTimer(clock, blockInterval, updateCurrentBuffer)
     val blockStorageLevel = storageLevel
     val blocksForPushing = new ArrayBlockingQueue[Block](1000)