add APT for retrieving slave counters
diff --git a/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/driver/Driver.java b/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/driver/Driver.java
index 4604bc7..b3a90e9 100644
--- a/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/driver/Driver.java
+++ b/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/driver/Driver.java
@@ -59,8 +59,8 @@
 
 @SuppressWarnings("rawtypes")
 public class Driver implements IDriver {
-    public static final String[] COUNTERS = { Counters.SYSTEM_LOAD, Counters.MEMORY_USAGE, Counters.DISK_READ,
-            Counters.DISK_WRITE, Counters.NETWORK_IO_READ, Counters.NETWORK_IO_WRITE };
+    public static final String[] COUNTERS = { Counters.NUM_PROCESSOR, Counters.SYSTEM_LOAD, Counters.MEMORY_USAGE,
+            Counters.DISK_READ, Counters.DISK_WRITE, Counters.NETWORK_IO_READ, Counters.NETWORK_IO_WRITE };
     private static final Log LOG = LogFactory.getLog(Driver.class);
     private IHyracksClientConnection hcc;
     private Class exampleClass;