diff --git a/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/context/RuntimeContext.java b/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/context/RuntimeContext.java
index 496d066..adcb702 100644
--- a/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/context/RuntimeContext.java
+++ b/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/context/RuntimeContext.java
@@ -54,14 +54,14 @@
     private final ILocalResourceRepository localResourceRepository;
     private final ResourceIdFactory resourceIdFactory;
     private final IBufferCache bufferCache;
-    private final IVirtualBufferCache vBufferCache;
+    private final List<IVirtualBufferCache> vbcs;
     private final IFileMapManager fileMapManager;
     private final IOManager ioManager;
     private final Map<Long, List<FileReference>> iterationToFiles = new ConcurrentHashMap<Long, List<FileReference>>();
     private final Map<StateKey, IStateObject> appStateMap = new ConcurrentHashMap<StateKey, IStateObject>();
     private final Map<String, Long> jobIdToSuperStep = new ConcurrentHashMap<String, Long>();
     private final Map<String, Boolean> jobIdToMove = new ConcurrentHashMap<String, Boolean>();
-    
+
     private final ThreadFactory threadFactory = new ThreadFactory() {
         public Thread newThread(Runnable r) {
             return new Thread(r);
@@ -81,8 +81,10 @@
                 new PreDelayPageCleanerPolicy(Long.MAX_VALUE), fileMapManager, pageSize, numPages, 1000000,
                 threadFactory);
         int numPagesInMemComponents = numPages / 8;
-        vBufferCache = new MultitenantVirtualBufferCache(new VirtualBufferCache(new HeapBufferAllocator(), pageSize,
-                numPagesInMemComponents));
+        vbcs = new ArrayList<IVirtualBufferCache>();
+        IVirtualBufferCache vBufferCache = new MultitenantVirtualBufferCache(new VirtualBufferCache(
+                new HeapBufferAllocator(), pageSize, numPagesInMemComponents));
+        vbcs.add(vBufferCache);
         ioManager = (IOManager) appCtx.getRootContext().getIOManager();
         lcManager = new NoBudgetIndexLifecycleManager();
         localResourceRepository = new TransientLocalResourceRepository();
@@ -129,8 +131,8 @@
         return bufferCache;
     }
 
-    public IVirtualBufferCache getVirtualBufferCache() {
-        return vBufferCache;
+    public List<IVirtualBufferCache> getVirtualBufferCaches() {
+        return vbcs;
     }
 
     public IFileMapProvider getFileMapManager() {
diff --git a/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/bootstrap/VirtualBufferCacheProvider.java b/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/bootstrap/VirtualBufferCacheProvider.java
index ec51047..f15b1c2 100644
--- a/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/bootstrap/VirtualBufferCacheProvider.java
+++ b/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/bootstrap/VirtualBufferCacheProvider.java
@@ -14,6 +14,8 @@
  */
 package edu.uci.ics.pregelix.runtime.bootstrap;
 
+import java.util.List;
+
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCacheProvider;
@@ -33,7 +35,7 @@
     }
     
     @Override
-    public synchronized IVirtualBufferCache getVirtualBufferCache(IHyracksTaskContext ctx) {
-        return RuntimeContext.get(ctx).getVirtualBufferCache();
+    public synchronized List<IVirtualBufferCache> getVirtualBufferCaches(IHyracksTaskContext ctx) {
+        return RuntimeContext.get(ctx).getVirtualBufferCaches();
     }
 }