Re: [jgroups-users] RPC request and response message prioritization

Hi Mike


> Can I remove PRIO in master then?
> [ME] Yes

[bela] OK, done



>> The problem I have is prioritizing the RPC method response which, as you
>> can image, is where the large amounts of data needs to be transferred.
>> The problem is that the RequestCorrelator, after calling the
>> RpcDispatcher.handle method, creates the response messages with a fixed
>> set of headers and thus it has removed the PrioHeader that I added in
>> the rsp instance in RpcDispatcher.handle.
>
> Wait: handle() returns an Object not a Message so how can you add
> headers there?
> [ME] Handles argument is a Message
> @Override
>      public Object handle( Message req) throws Exception {
> I add the PrioHeader to the req argument


[bela]
I don't understand: req is the request and should already have a 
PrioHeader. What you'd need to add a header to is the returned Object 
which is later wrapped in a message, wouldn't you?

> If you extended RequestCorrelator.sendReply() and set your subclass in
> RpcDispatcher, would that help? Or you could override sendResponse() or
> prepareResponse().
> [ME] Good Idea.  I extended RpcDispatcher and RequestCorrelator and override the necessary methods (1 method in each class) and it worked fine.  Thanks!


[bela]
I also added MessageDispatcher.correlator(RequestCorrelator c) to set 
the RequestCorrelator


> Or would subclassing RequestCorrelator and setting it in RpcDispatcher
> work for you?
>
> [ME] --- As mentioned above, extending those two classes was perfect!

OK, great!


-- 
Bela Ban, JGroups lead (http://www.jgroups.org)


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