This is actually starting to look hopeful. We have to add the cache replicator to each cache as we programmatically create them. Make sure we only do so when we have a distributed configuration.

src/java/com/samskivert/jdbc/depot/EHCacheAdapter.java

@@ -25,6 +25,11 @@ import java.io.Serializable;
 import net.sf.ehcache.Cache;
 import net.sf.ehcache.CacheManager;
 import net.sf.ehcache.Element;
+import net.sf.ehcache.distribution.CacheManagerPeerListener;
+import net.sf.ehcache.distribution.CacheManagerPeerProvider;
+import net.sf.ehcache.distribution.RMIAsynchronousCacheReplicator;
+
+import static com.samskivert.jdbc.depot.Log.log;
 
 /**
  * An implementation of {@link CacheAdapter} for ehcache.
@@ -35,6 +40,18 @@ public class EHCacheAdapter
     public EHCacheAdapter ()
     {
         _cachemgr = CacheManager.getInstance();
+
+        CacheManagerPeerListener listener = _cachemgr.getCachePeerListener();
+        CacheManagerPeerProvider provider = _cachemgr.getCachePeerProvider();
+        if ((provider != null) != (listener != null)) {
+            // we want either both listener and provider, or neither
+            log.warning("EHCache misconfigured, distributed mode disabled [listener =" +
+                listener + ", provider=" + provider);
+            _distributed = false;
+
+        } else {
+            _distributed = (listener != null);
+        }
     }
 
     public <T> CacheBin<T> getCache (String id)
@@ -90,6 +107,14 @@ public class EHCacheAdapter
             _cache = _cachemgr.getCache(id);
             if (_cache == null) {
                 _cache = new Cache(id, 5000, false, false, 600, 60);
+
+                if (_distributed) {
+                    // for reasons unknown we have to add this event listener programmatically
+                    // rather than include it in the defaultCache portion of the ehcache.xml
+                    // configuration file.
+                    _cache.getCacheEventNotificationService().registerListener(
+                        new RMIAsynchronousCacheReplicator(true, true, true, true, 1000));
+                }
                 _cachemgr.addCache(_cache);
             }
         }
@@ -103,5 +128,6 @@ public class EHCacheAdapter
         CacheManager.getInstance().shutdown();
     }
 
+    protected boolean _distributed;
     protected CacheManager _cachemgr;
 }