Cache Listener Issue

Question

How can one invoke multiple listeners listening to the same cache simultaneously with multiple events being triggered ?
To explain my question in a more clear manner I wrote a small Helloworld-Listener program.
public class multipleListenersMDB implements MessageListener {
public void onMessage(Message message) {
// TODO Auto-generated method stub
NamedCache listenerCache = CacheFactory.getCache("listenerCache");
listenerCache.addMapListener((MapListener) new CacheListener(), "1", false);
listenerCache.addMapListener((MapListener) new CacheListener(), "2", false);
listenerCache.addMapListener((MapListener) new CacheListener(), "3", false);
listenerCache.put("1", "1-RexUpdated");
listenerCache.put("2", "2-RexUpdated");
listenerCache.put("3", "3-RexUpdated");
CacheListener
=========
public class CacheListener extends AbstractMapListener{
     private static Logger logger = Logger.getLogger(CacheListener.class.getName());;
     public void entryInserted(MapEvent Event) {
          String keyValue = (String) Event.getNewValue();
          int delay = 20000;
          long stopTime;
          long startTime = stopTime = System.currentTimeMillis();
          System.out.println("Value:" + keyValue + " startTime:" + startTime + " millis");
          while (stopTime - startTime < delay) {
               stopTime = System.currentTimeMillis();
          System.out.println("Value:" + keyValue + " exitTime:" + stopTime + " millis");
Here is the output of this program
Value:1-RexUpdated startTime:1320379443254 millis
Value:1-RexUpdated exitTime:1320379463254 millis
Value:2-RexUpdated startTime:1320379463254 millis
Value:2-RexUpdated exitTime:1320379483254 millis
Value:3-RexUpdated startTime:1320379483254 millis
Value:3-RexUpdated exitTime:1320379503254 millis
What I had expected to see was basically Value:1-Rex, Value:2-Rex and Value:3-Rex listeners to be invoked not one after the other but in parallel.
If you see curently Listener1 for 1-Rex is invoked followed by Listener2 for 2-Rex and then followed by Listener for 3-Rex.
Perhaps this displays my issue clearly and you will be able to use your magic powers to help me.
PS: I have multiple threadcount for the cache configured already
Thanks :)
Edited by: 807103 on Nov 4, 2011 6:06 AM
Edited by: 807103 on Nov 4, 2011 9:54 AM

Answer 1

Hi Reon
The results you are seeing are correct. You can use a listener as a "client" listener or as a backing map listener. Normally, applications only use client listeners where cache events are delivered to the client listener regardless of data location. As you observed, the backing map listener is invoked in the JVM where the data (partition) resides. Backing map listeners are considered and advanced feature, used in special cases, for example when post processing needs to be done within the grid.
Typically, client listeners are registered dynamically, they are not configured in the xml file. This allows you to listen for specific events or events on specific keys, something you cannot do if you register the listener in the configuration file.
Please http://coherence.oracle.com/display/COH35UG/Deliver+events+for+changes+as+they+occur
Paul