Coherence *Extend configuration

Question

Hello,
To enable Coherence Extend, we should define a proxy-scheme in our cluster cache-config that defines a coherence *extend proxy-service, containing a tcp-acceptor with a local  address and port.
Can there be only 1 such an extend proxy service running on the same node?  Or should we redefine the extend proxy-service configuration for each cache server that is running on the same node (to use a different port)? In both cases, we have to define at least 2 new cache-config files - one with the extend proxy service and one without. Is this correct?
We're now trying to run 2 cache servers on the same node with an extend proxy service.  When we try to start the 2nd cache server, we get the following exception (which is quite normal because the coherence proxy service tries to bind to a socket that is already in use by the other cache server instance that is running the extend proxy service):
2010-01-21 09:48:10.923/7.865 Oracle Coherence GE 3.5.2/463 <Error> (thread=Proxy:ExtendTcpProxyService:TcpAcceptor:TcpProcessor, member=1): error binding ServerSocket to 10.2.12.144:9099: java.net.BindException: Address already in use
at sun.nio.ch.Net.bind(Native Method)
at sun.nio.ch.ServerSocketChannelImpl.bind(Unknown Source)
at sun.nio.ch.ServerSocketAdaptor.bind(Unknown Source)
at com.tangosol.coherence.component.util.daemon.queueProcessor.service.peer.acceptor.TcpAcceptor.configureSocket(TcpAcceptor.CDB:27)
at com.tangosol.coherence.component.util.daemon.queueProcessor.service.peer.acceptor.TcpAcceptor$TcpProcessor.onEnter(TcpAcceptor.CDB:25)
at com.tangosol.coherence.component.util.Daemon.run(Daemon.CDB:14)
at java.lang.Thread.run(Unknown Source)
Is there a workaround that makes it possible to use the same cache configuration (containing coherence *extend proxy-service, with tcp-acceptor) with different cache servers on the same machine? 
If not, what is the best practice to configure the *extend proxy service?
Thanks in advance

Answer 1

you can inject system properties into your coherence cache configuration as follows:
<tcp-acceptor>
<local-address>
<address system-property="wouters.address">localhost</address>
<port system-property="wouters.port">1234</port>
</local-address>
</tcp-acceptor>
The above example will default to localhost:1234, however you can override these with system properties. This will allow you to reuse the same config, but tailor it to your application.
Cheers,
Neville.