Cache "dist-test" does not support pass-through optimization

Question

I have noticed this message in the log of my Extend proxy JVM. It is logged at INFO level.
The cache dist-test does not support pass-through optimization for objects in internal format. If possible, consider using a different cache topology.
The Extend proxy JVM is running as a storage disabled node of the cluster.
Any ideas what is causing it?
dist-test is configured like this:
  <caching-scheme-mapping>
    <cache-mapping>
      <cache-name>dist-*</cache-name>
      <scheme-name>near-entitled-scheme</scheme-name>
    </cache-mapping>
  </caching-scheme-mapping>
  <caching-schemes>
    <near-scheme>
      <scheme-name>near-entitled-scheme</scheme-name>
      <front-scheme>
        <local-scheme>
          <eviction-policy>HYBRID</eviction-policy>
          <high-units>1000</high-units>
        </local-scheme>
      </front-scheme>
      <back-scheme>
        <distributed-scheme>
          <scheme-ref>dist-default</scheme-ref>
        </distributed-scheme>
      </back-scheme>
    </near-scheme>
    <distributed-scheme>
      <scheme-name>dist-default</scheme-name>
      <serializer>
        <class-name>com.tangosol.io.pof.ConfigurablePofContext</class-name>
      </serializer>
      <lease-granularity>member</lease-granularity>
      <backing-map-scheme>
        <local-scheme>
          <listener>
            <class-scheme>
              <class-name>{backing-map-listener-class-name com.oracle.coherence.common.backingmaplisteners.NullBackingMapListener}</class-name>
              <init-params>
                <init-param>
                  <param-type>com.tangosol.net.BackingMapManagerContext</param-type>
                  <param-value>{manager-context}</param-value>
                </init-param>
              </init-params>
            </class-scheme>
          </listener>
        </local-scheme>
      </backing-map-scheme>
      <autostart>true</autostart>
    </distributed-scheme>
  </caching-schemes>I presume it is something to do with the near-scheme because I do not see the message if I map dist-* caches directly to the dist-default scheme
Cheers,
JK.

Answer 1

Hi Jonathan,
You are getting the warning because a near cache caches Objects. Since the the proxy service is using POF, it must deserialize the POF serialized value in order to put it in the near cache. You don't see the message when you cache directly to the dist-default scheme because that scheme is configured to use POF, which allows the proxy service to pass the POF serialized value directly through to the distributed cache service.
Thanks,
Tom