JCS LateralTCPCacheFactory

[Greg Parker <gm...@gmail.com>]

I'm trying to get a sample cluster of tomcat servers (server A, B and C) to use a distributed cache.  The ‘hello’ cache is configured on each server with a different TcpListenerPort on each server (8020, 8021, 8022) like this:

jcs.region.hello=LTCP
…

jcs.auxiliary.LTCP=org.apache.commons.jcs.auxiliary.lateral.socket.tcp.LateralTCPCacheFactory
jcs.auxiliary.LTCP.attributes=org.apache.commons.jcs.auxiliary.lateral.socket.tcp.TCPLateralCacheAttributes
jcs.auxiliary.LTCP.attributes.UdpDiscoveryEnabled=false
jcs.auxiliary.LTCP.attributes.AllowGet=true
jcs.auxiliary.LTCP.attributes.Receive=true
jcs.auxiliary.LTCP.attributes.TcpListenerPort=8020
jcs.auxiliary.LTCP.attributes.TcpServers=localhost:8020,localhost:8021,localhost:8022


Server A has a page that sets a value in the cache like this:

        cache = JCS.getInstance("hello");
        cache.put(“message", “Hello from server A");


Server B, and C try to get the value without setting it:

        cache = JCS.getInstance("hello");
        add(new Label("message", "Server B -> cache has : " +  cache.get(“message");));


The first time I access the page on server A I get an exception -  "Cannot connect to localhost:8021”.  If I access the page on each server then things appear to start communicating; however, the “message” entry from the “hello” region is set on server A and null on B and C.  Sometimes I see the value on server C displayed properly but never on server B.

With a configuration like this should I expect to see values immediately distributed to the other servers?  

Is there a way I should be bootstrapping the cache when the server starts?  If the servers need to communicate with one another it would seem to me that they need to be listening long before the first time the server tries to access the cache.

For performance I would like to use the cache to store serialized XML data instead of storing it in the session or a database.  The data remains in the cache while the user transforms it through several request cycles.  So during a request cycle the XML data would be retrieved, transformed, and stored back in the cache.  In a clustered environment I need the XML data available on every server in the cluster.  Is this an acceptable use case for JCS?

Thanks