[jbosscache-dev] JGroups RpcDIspatcher, GroupRequest and configurable filtering algorithms?

[Manik Surtani]

Guys,

Are there any plans to implement a way to register a filter when  
using the RpcDispatcher when waiting for results?

Current options (GroupRequest.GET_ALL, GET_NONE, GET_MOST, GET_FIRST,  
etc) is insufficient where you want the call to block until the first  
*acceptable* response is received.

Basically, if I expect responses from everyone in the cluster but  
want to wait for the first acceptable response, I have no choice but  
to do a GET_ALL and then parse all the responses for the first  
acceptable one.  Now the definition of an acceptable response is  
application-specific, and so perhaps a mechanism to register a filter  
would be useful.  Perhaps something like:

	RpcDispatcher.callRemoteMethods(Vector dests, MethodCall call, int  
mode, long timeout, boolean use_anycasting, ResponseFilter  
responseFilter)

	public interface ResponseFilter
	{
		boolean isAcceptable(Object response);
	}

If a filter is provided, only responses that pass the isAcceptable()  
test is added to the response list.  Then GroupRequest.GET_FIRST  
could be used and we could have a very efficient mechanism of not  
having to wait for all responses.

WDYT?

Cheers,
--
Manik Surtani

Lead, JBoss Cache
JBoss, a division of Red Hat

Email: manik at jboss.org
Telephone: +44 7786 702 706
MSN: manik at surtani.org
Yahoo/AIM/Skype: maniksurtani