The first thing I would do would be to disable the executor and try again.
You could be encountering some sort of deadlock.
On Sep 24, 2013 12:47 PM, "Christian Hammers" <[email protected]>
wrote:
> Hello
>
> I've written a server for a proprietary UDP protocol that needs to answer
> with
> exactly one packet for every incoming packet. All packets are independent
> from
> each other so that I like to have each one handled asynchronously by a
> different thread from a pool with a certain maximum size.
>
> So far I used this:
>
> FooCodec codec = new FooCodec(); // encoder and decoder in one
> class
> InetSocketAddress local = new InetSocketAddress(port);
>
> acceptor = new NioDatagramAcceptor();
> acceptor.getFilterChain().addLast("executor", new
> ExecutorFilter(maxThreads));
> acceptor.getFilterChain().addLast("codec", new
> ProtocolCodecFilter(codec, codec));
> acceptor.setHandler(handler);
> acceptor.bind(local);
>
> At first it seemed that each incoming UDP package, due to its stateless
> nature,
> creates a different Mina "session" and each Mina "session" runs in its own
> thread so that the default ExecutorFilter implementation
> OrderedThreadPoolExecutor is fine as I certainly don't want the session
> closed
> if there is still a response before it in the queue.
>
> Now under a bit of load, one session was a bit slower and hanging for 1,5s
> and
> it suddenly happened that multiple UDP packets were put into the same
> Mina "session" which lead to the following log messages:
>
> 2013-09-24 10:56:02,910 DEBUG
> org.apache.mina.filter.executor.OrderedThreadPoolExecutor :
> Adding event MESSAGE_RECEIVED to session 17529
> Queue : [MESSAGE_RECEIVED, , MESSAGE_RECEIVED, , MESSAGE_RECEIVED ... ]
> (OrderedThreadPoolExecutor.java:431)
>
> This now completely destroys the asynchronous behaviour as all packeges
> had to wait
> for the first one in the queue even if there were several executor threads
> idling
> around!
>
> How should I fix this problem? Using an "UnorderedThreadPoolExecutor?
> Or setting acceptor.getSessionConfig().setIdleTime(IdleStatus.BOTH_IDLE,
> 0);
> Or by somehow else force the creation of a Mina "session" for each UDP
> packet?
>
> Best Regards
>
> -christian-
>
>
> P.S.: http://mina.apache.org/mina-project/documentation.html contains a
> links to a "UDP Tutorial" which sadly refers to a page that does
> only have APR and Serial tutorials.
>
