[infinispan-dev] ISPN-2808 - thread pool for incoming message [feedback]

[Pedro Ruivo]

On 02/28/2013 03:47 PM, Mircea Markus wrote:
>
> On 28 Feb 2013, at 15:31, Pedro Ruivo wrote:
>
>>>
>>> On 27 Feb 2013, at 19:06, Pedro Ruivo wrote:
>>>
>>>> Hi all,
>>>>
>>>> I'm working on ISPN-2808 and I want some feedback about it (code is
>>>> here [1])
>>>>
>>>> I'm starting to implement this feature but I know that Asynchronous
>>>> Invocation API is not totally finished in JGroups.
>>>>
>>>> My idea in to use an executor service in CommandAwareRpcDispatcher
>>>> (CARD) and when a request (command) is received, it checks if it is
>>>> useful to move the command execution to another thread (in this line [2])
>>>>
>>>> For now, I'm thinking to move all the write commands, lock control
>>>> command, prepare command and commit command to the executor service
>>>> (Note: commit command is only moved when in DIST mode and L1 is enabled).
>>>
>>> you might want to move Commit there when we have a tx cache and cache
>>> store - it's during the commit where the data is written to the cache
>>> store and that might take time.
>>>
>>>> first question: do you think it is fine to move the commands to the
>>>> executor service in CARD or should I move this functionally to the
>>>> InvoundHandler?
>>> +1 for the InboundInvocationHandler: with ISPN-2849 we'll build the tx
>>> dependency right before invoking the interceptor chain (potentially in a
>>> new interceptor), so i think the closer you move it to the interceptor
>>> chain the better.
>> So do you think that is better to create a new interceptor to dispatch
>> the commands to the thread pool? (at least for the VisitableCommands).
>> And put this new interceptor after the InvocationContextInterceptor?
> we shouldn't create an interceptor yet, perhaps we'll do that with ISPN-2849.
>>
>> My opinion, it to dispatch the command to a new thread before invoking
>> command.perform() in order to avoid to move some ThreadLocal variable,
>> set by the perform() method.
> +1
However I prefer to do this dispatch in CARD to avoid make to code more 
complex and duplicate it. I mean, in CARD we have:

handle() {
if is from another site
   process from another site
else
   if is cache rpc command
     inboundInvocationHandler.handle
   else
     command.perform
}

and if I move the dispatch inside the InbounInvocationHandler, as 
suggested, I will have to duplicate the code for each branch of the IF, 
namelly:

try
   command.perform
   transport.sendResponse
catch Thowable t
   transport.sendResponse(ExceptionResponse)

any thoughts?

>
> Cheers,
>