diff --git a/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/PageRankVertex.java b/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/PageRankVertex.java
index 02e1625..b6d4da7 100644
--- a/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/PageRankVertex.java
+++ b/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/PageRankVertex.java
@@ -54,6 +54,7 @@
     public static final String ITERATIONS = "HyracksPageRankVertex.iteration";
     private DoubleWritable outputValue = new DoubleWritable();
     private DoubleWritable tmpVertexValue = new DoubleWritable();
+    private int maxIteration = -1;
 
     /**
      * Test whether combiner is called by summing up the messages.
@@ -97,7 +98,9 @@
 
     @Override
     public void compute(Iterator<DoubleWritable> msgIterator) {
-        int maxIteration = getContext().getConfiguration().getInt(ITERATIONS, 10);
+        if (maxIteration < 0) {
+            maxIteration = getContext().getConfiguration().getInt(ITERATIONS, 10);
+        }
         if (getSuperstep() == 1) {
             tmpVertexValue.set(1.0 / getNumVertices());
             setVertexValue(tmpVertexValue);
diff --git a/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ReachabilityVertex.java b/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ReachabilityVertex.java
index daafc82..2792d88 100644
--- a/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ReachabilityVertex.java
+++ b/pregelix-example/src/main/java/edu/uci/ics/pregelix/example/ReachabilityVertex.java
@@ -85,6 +85,7 @@
     }
 
     private ByteWritable tmpVertexValue = new ByteWritable();
+    private long sourceId = -1;
 
     /** The source vertex id */
     public static final String SOURCE_ID = "ReachibilityVertex.sourceId";
@@ -101,7 +102,7 @@
      * @return True if the source id
      */
     private boolean isSource(VLongWritable v) {
-        return (v.get() == getContext().getConfiguration().getLong(SOURCE_ID, SOURCE_ID_DEFAULT));
+        return (v.get() == sourceId);
     }
 
     /**
@@ -116,6 +117,9 @@
     @Override
     public void compute(Iterator<ByteWritable> msgIterator) {
         if (getSuperstep() == 1) {
+            if (sourceId < 0) {
+                sourceId = getContext().getConfiguration().getLong(SOURCE_ID, SOURCE_ID_DEFAULT);
+            }
             boolean isSource = isSource(getVertexId());
             if (isSource) {
                 tmpVertexValue.set((byte) 1);
@@ -160,7 +164,7 @@
         }
         voteToHalt();
     }
-    
+
     @Override
     public String toString() {
         return getVertexId() + " " + getVertexValue();