WrapperNamedCache

Question

I'm having some trouble getting the WrapperNamedCache to work.
When I try to use the cache from a client it throws the following exception:
Application code running on "DistributedCache" service thread(s) should not call ensureCache as this may result in deadlock. The most common case is a CacheFactory call from a custom CacheStore implementation.
2009-04-17 14:05:10.736/6.157 Oracle Coherence GE 3.4.1/407 <Warning> (thread=DistributedCache, member=1): Application code running on "DistributedCache" service thread(s) should not call ensureCache as this may result in deadlock. The most common case is a CacheFactory call from a custom CacheStore implementation.
2009-04-17 14:05:10.751/6.172 Oracle Coherence GE 3.4.1/407 <Error> (thread=DistributedCache, member=1): Assertion failed: poll() is a blocking call and cannot be called on the Service thread
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.Grid.poll(Grid.CDB:4)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.Grid.poll(Grid.CDB:11)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache$BinaryMap.sendPartitionedRequest(DistributedCache.CDB:59)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache$BinaryMap.size(DistributedCache.CDB:13)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache$BinaryMap.isEmpty(DistributedCache.CDB:1)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache$BinaryMap$KeySet.isEmpty(DistributedCache.CDB:1)
     at com.tangosol.util.ConverterCollections$ConverterCollection.isEmpty(ConverterCollections.java:483)
     at com.tangosol.util.AbstractKeySetBasedMap.isEmpty(AbstractKeySetBasedMap.java:48)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache$Storage.instantiateResourceMap(DistributedCache.CDB:25)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache$Storage.setCacheName(DistributedCache.CDB:27)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache$ConfigListener.entryInserted(DistributedCache.CDB:15)
     at com.tangosol.util.MapEvent.dispatch(MapEvent.java:191)
     at com.tangosol.util.MapEvent.dispatch(MapEvent.java:164)
     at com.tangosol.util.MapListenerSupport.fireEvent(MapListenerSupport.java:556)
     at com.tangosol.util.ObservableHashMap.dispatchEvent(ObservableHashMap.java:229)
     at com.tangosol.util.ObservableHashMap$Entry.onAdd(ObservableHashMap.java:270)
     at com.tangosol.util.SafeHashMap.put(SafeHashMap.java:244)
     at com.tangosol.coherence.component.util.collections.WrapperMap.put(WrapperMap.CDB:1)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.Grid$ServiceConfigMap.put(Grid.CDB:13)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache$StorageIdRequest.onReceived(DistributedCache.CDB:40)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.Grid.onMessage(Grid.CDB:9)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.Grid.onNotify(Grid.CDB:130)
     at com.tangosol.coherence.component.util.daemon.queueProcessor.service.grid.DistributedCache.onNotify(DistributedCache.CDB:3)
     at com.tangosol.coherence.component.util.Daemon.run(Daemon.CDB:37)
     at java.lang.Thread.run(Unknown Source)Here's the configuration
<!DOCTYPE cache-config SYSTEM "cache-config.dtd">
<cache-config>
  <caching-scheme-mapping>
    <cache-mapping>
      <cache-name>*</cache-name>
      <scheme-name>distributed-scheme</scheme-name>
    </cache-mapping>
  </caching-scheme-mapping>
  <caching-schemes>
    <!-- Distributed caching scheme. -->
    <distributed-scheme>
      <scheme-name>distributed-scheme</scheme-name>
      <service-name>DistributedCache</service-name>
      <serializer>
        <class-name>com.tangosol.io.pof.ConfigurablePofContext</class-name>
      </serializer>
      <backing-map-scheme>
        <class-scheme>
          <scheme-ref>entitled-scheme</scheme-ref>
        </class-scheme>
      </backing-map-scheme>
      <autostart>true</autostart>
    </distributed-scheme>
    <!-- Wrapped caching scheme. -->
    <class-scheme>
      <scheme-name>entitled-scheme</scheme-name>
      <class-name>com.tangosol.net.cache.WrapperNamedCache</class-name>
      <init-params>
        <init-param>
          <param-type>{cache-ref}</param-type>
          <param-value>{cache-name}</param-value>
        </init-param>
        <init-param>
          <param-type>string</param-type>
          <param-value>{cache-name}</param-value>
        </init-param>
      </init-params>
    </class-scheme>
  </caching-schemes>
</cache-config>Edited by: pards on Apr 17, 2009 11:10 AM

Answer 1

The WrapperNamedCache cannot be used as a backing map; a cache cannot be used as a backing map.
I assume that you tried this approach as an alternative to the WrapperNamedCache used in the proxy for security. Please see my reply to that thread:
Re: Row-level security?
--David