diff --git a/graphx/src/main/scala/org/apache/spark/graphx/WikiPipelineBenchmark.scala b/graphx/src/main/scala/org/apache/spark/graphx/WikiPipelineBenchmark.scala
index 86e52ce20f5e4..4aa2e793152e0 100644
--- a/graphx/src/main/scala/org/apache/spark/graphx/WikiPipelineBenchmark.scala
+++ b/graphx/src/main/scala/org/apache/spark/graphx/WikiPipelineBenchmark.scala
@@ -77,6 +77,7 @@ object WikiPipelineBenchmark extends Logging {
       val startTime = System.currentTimeMillis
       logWarning("starting pagerank")
       // GRAPH VIEW
+      val ccStartTime = System.currentTimeMillis
       val ccGraph = ConnectedComponents.run(currentGraph).cache
       val zeroVal = new JTreeSet[VertexId]()
       val seqOp = (s: JTreeSet[VertexId], vtuple: (VertexId, VertexId)) => {
@@ -89,9 +90,14 @@ object WikiPipelineBenchmark extends Logging {
       }
       // TABLE VIEW
       val numCCs = ccGraph.vertices.aggregate(zeroVal)(seqOp, combOp).size()
+      val ccEndTime = System.currentTimeMillis
+      logWarning(s"Connected Components TIMEX: ${(ccEndTime - ccStartTime)/1000.0}")
       logWarning(s"Number of connected components for iteration $i: $numCCs")
+      val prStartTime = System.currentTimeMillis
       val pr = PageRank.run(currentGraph, 20).cache
       pr.vertices.count
+      val prEndTime = System.currentTimeMillis
+      logWarning(s"Pagerank TIMEX: ${(prEndTime - prStartTime)/1000.0}")
       logWarning("Pagerank completed")
       // TABLE VIEW
       val prAndTitle = currentGraph.outerJoinVertices(pr.vertices)({(id: VertexId, title: String, rank: Option[Double]) => (title, rank.getOrElse(0.0))}).cache
@@ -106,7 +112,11 @@ object WikiPipelineBenchmark extends Logging {
       }
       val newGraph = currentGraph.subgraph(x => true, filterTop20).cache
       newGraph.vertices.count
-      logWarning(s"TIMEX iter $i ${(System.currentTimeMillis - startTime)/1000.0}")
+      logWarning(s"TOTAL_TIMEX iter $i ${(System.currentTimeMillis - startTime)/1000.0}")
+      currentGraph.unpersistVertices(blocking = false)
+      ccGraph.unpersistVertices(blocking = false)
+      pr.unpersistVertices(blocking = false)
+      prAndTitle.unpersistVertices(blocking = false)
       currentGraph = newGraph
     }
     currentGraph
diff --git a/graphx/src/main/scala/org/apache/spark/graphx/impl/RoutingTable.scala b/graphx/src/main/scala/org/apache/spark/graphx/impl/RoutingTable.scala
index fe44e1ee0c391..35245971912d7 100644
--- a/graphx/src/main/scala/org/apache/spark/graphx/impl/RoutingTable.scala
+++ b/graphx/src/main/scala/org/apache/spark/graphx/impl/RoutingTable.scala
@@ -49,24 +49,28 @@ class RoutingTable(edges: EdgeRDD[_], vertices: VertexRDD[_]) {
       includeSrcAttr: Boolean, includeDstAttr: Boolean): RDD[Array[Array[VertexId]]] = {
     // Determine which vertices each edge partition needs by creating a mapping from vid to pid.
     val vid2pid: RDD[(VertexId, PartitionID)] = edges.partitionsRDD.mapPartitions { iter =>
-      val (pid: PartitionID, edgePartition: EdgePartition[_]) = iter.next()
-      val numEdges = edgePartition.size
-      val vSet = new VertexSet
-      if (includeSrcAttr) {  // Add src vertices to the set.
-        var i = 0
-        while (i < numEdges) {
-          vSet.add(edgePartition.srcIds(i))
-          i += 1
+      if (iter.hasNext) {
+        val (pid: PartitionID, edgePartition: EdgePartition[_]) = iter.next()
+        val numEdges = edgePartition.size
+        val vSet = new VertexSet
+        if (includeSrcAttr) {  // Add src vertices to the set.
+          var i = 0
+          while (i < numEdges) {
+            vSet.add(edgePartition.srcIds(i))
+            i += 1
+          }
         }
-      }
-      if (includeDstAttr) {  // Add dst vertices to the set.
-      var i = 0
-        while (i < numEdges) {
-          vSet.add(edgePartition.dstIds(i))
-          i += 1
+        if (includeDstAttr) {  // Add dst vertices to the set.
+        var i = 0
+          while (i < numEdges) {
+            vSet.add(edgePartition.dstIds(i))
+            i += 1
+          }
         }
+        vSet.iterator.map { vid => (vid, pid) }
+      } else {
+        Iterator.empty
       }
-      vSet.iterator.map { vid => (vid, pid) }
     }
 
     val numPartitions = vertices.partitions.size