diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ResetableByteArrayInputStream.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ResetableByteArrayInputStream.java
index 7d5f627..f9cad9f 100755
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ResetableByteArrayInputStream.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/util/ResetableByteArrayInputStream.java
@@ -36,19 +36,12 @@
     public int read() {
         int remaining = data.length - position;
         int value = remaining > 0 ? (data[position++] & 0xff) : -1;
-        if (LOGGER.isLoggable(Level.FINEST)) {
-            LOGGER.finest("read(): value: " + value + " remaining: " + remaining + " position: " + position);
-        }
         return value;
     }
 
     @Override
     public int read(byte[] bytes, int offset, int length) {
         int remaining = data.length - position;
-        if (LOGGER.isLoggable(Level.FINEST)) {
-            LOGGER.finest("read(bytes[], int, int): remaining: " + remaining + " offset: " + offset + " length: "
-                    + length + " position: " + position);
-        }
         if (remaining == 0) {
             return -1;
         }
@@ -57,4 +50,9 @@
         position += l;
         return l;
     }
-}
\ No newline at end of file
+
+    @Override
+    public int available() {
+        return data.length - position;
+    }
+}
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/CopyUpdateUtil.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/CopyUpdateUtil.java
index 8709301..8e731ba 100644
--- a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/CopyUpdateUtil.java
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/CopyUpdateUtil.java
@@ -33,8 +33,8 @@
             int srcStart = fieldEndOffsets[0];
             int srcLen = fieldEndOffsets[1] - fieldEndOffsets[0]; // the updated vertex size
             int frSize = frameTuple.getFieldLength(1); // the vertex binary size in the leaf page
-            if (srcLen <= frSize) {
-                //doing in-place update if possible, save the "real update" overhead
+            if (srcLen == frSize) {
+                //doing in-place update if the vertex size is fixed, save the "real update" overhead
                 System.arraycopy(cloneUpdateTb.getByteArray(), srcStart, frameTuple.getFieldData(1),
                         frameTuple.getFieldStart(1), srcLen);
                 cloneUpdateTb.reset();
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/ResetableByteArrayInputStream.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/ResetableByteArrayInputStream.java
index b697466..5be9ffc 100644
--- a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/ResetableByteArrayInputStream.java
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/ResetableByteArrayInputStream.java
@@ -15,11 +15,8 @@
 package edu.uci.ics.pregelix.dataflow.util;
 
 import java.io.InputStream;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
 public class ResetableByteArrayInputStream extends InputStream {
-    private static final Logger LOGGER = Logger.getLogger(ResetableByteArrayInputStream.class.getName());
 
     private byte[] data;
     private int position;
@@ -36,19 +33,12 @@
     public int read() {
         int remaining = data.length - position;
         int value = remaining > 0 ? (data[position++] & 0xff) : -1;
-        if (LOGGER.isLoggable(Level.FINEST)) {
-            LOGGER.finest("read(): value: " + value + " remaining: " + remaining + " position: " + position);
-        }
         return value;
     }
 
     @Override
     public int read(byte[] bytes, int offset, int length) {
         int remaining = data.length - position;
-        if (LOGGER.isLoggable(Level.FINEST)) {
-            LOGGER.finest("read(bytes[], int, int): remaining: " + remaining + " offset: " + offset + " length: "
-                    + length + " position: " + position);
-        }
         if (remaining == 0) {
             return -1;
         }
@@ -57,4 +47,9 @@
         position += l;
         return l;
     }
+
+    @Override
+    public int available() {
+        return data.length - position;
+    }
 }
\ No newline at end of file
diff --git a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/TupleDeserializer.java b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/TupleDeserializer.java
index 6386bdb..85f3959 100644
--- a/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/TupleDeserializer.java
+++ b/pregelix/pregelix-dataflow-std/src/main/java/edu/uci/ics/pregelix/dataflow/util/TupleDeserializer.java
@@ -49,7 +49,7 @@
                 int availableBefore = bbis.available();
                 Object instance = recordDescriptor.getFields()[i].deserialize(di);
                 int availableAfter = bbis.available();
-                if (availableBefore - availableAfter > len) {
+                if (availableBefore - availableAfter != len) {
                     throw new IllegalStateException(ERROR_MSG);
                 }
 
@@ -82,7 +82,7 @@
                 int availableBefore = bbis.available();
                 Object instance = recordDescriptor.getFields()[i].deserialize(di);
                 int availableAfter = bbis.available();
-                if (availableBefore - availableAfter > fieldLength) {
+                if (availableBefore - availableAfter != fieldLength) {
                     throw new IllegalStateException(ERROR_MSG);
 
                 }
@@ -97,7 +97,7 @@
                 int availableBefore = bbis.available();
                 Object instance = recordDescriptor.getFields()[i].deserialize(di);
                 int availableAfter = bbis.available();
-                if (availableBefore - availableAfter > len) {
+                if (availableBefore - availableAfter != len) {
                     throw new IllegalStateException(ERROR_MSG);
                 }
                 record[i] = instance;
@@ -127,7 +127,7 @@
                 int availableBefore = bbis.available();
                 Object instance = recordDescriptor.getFields()[i].deserialize(di);
                 int availableAfter = bbis.available();
-                if (availableBefore - availableAfter > fieldLength) {
+                if (availableBefore - availableAfter != fieldLength) {
                     throw new IllegalStateException(ERROR_MSG);
                 }
                 record[i] = instance;
@@ -141,7 +141,7 @@
                 int availableBefore = bbis.available();
                 Object instance = recordDescriptor.getFields()[i].deserialize(di);
                 int availableAfter = bbis.available();
-                if (availableBefore - availableAfter > fieldLength) {
+                if (availableBefore - availableAfter != fieldLength) {
                     throw new IllegalStateException(ERROR_MSG);
                 }
                 record[i] = instance;
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/MsgListNullWriterFactory.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/MsgListNullWriterFactory.java
index 4eaa21c..b7689de 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/MsgListNullWriterFactory.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/touchpoint/MsgListNullWriterFactory.java
@@ -32,6 +32,7 @@
             @Override
             public void writeNull(DataOutput out) throws HyracksDataException {
                 try {
+                    out.writeByte(3); //start|end
                     out.writeInt(0);
                 } catch (IOException e) {
                     throw new HyracksDataException(e);