Concurrent (async, queue) Message processing - design issue

Question

Hi,
The question pertains to the following scenario:
1. A single input gateway (queue) for messages.
2. Messages arriving from different systems. High incidence (>30 within a
min) during specific periods
3. Message should be processed in near real-time as and when it arrives.
4. A non-polling (async) client.
I'd thought of two diff approaches for it:
1> Have a lightweight single-threaded message consumer -
init connection etc and register a listener (both msg and excep).
start connection . wait indefinitely
Listener onMessage creates new thread for working and returns.
Worker thread - parses xml in message and updates database
2>Have a single main-thread with sub-threads
Each sub-thread has own session and consumer and listener instance
processing of messages is done in sub-thread itself.
Which approach would be better suited ? Is there any other approach (
(which of the above goes easy on resources, which is faster)
Thanks in advance.
Anshu.

Answer 1

It depends on how concurrent you want to be.
If you want to process the messages in order in a single thread; use 1 connection, session, consumer, thread.
However one of the main reasons for using queues is they provide load balancing across processes or threads. If you want some parallelisation, use 1 connection but many sessions & consumers (1 consumer per session) which will each have its own thread.
For ultimate performance & pooling of connections, sessions, threads as well as the MessageListener POJOs together with exception handling & transaction management use something like Message Driven POJOs...
http://jencks.org/Message+Driven+POJOs
Though if you are talking about 30-60 messages a minute, unless it takes you 1 second to process 1 message, those are very low throughput rates, so probably 1 single thread could do it :)
James
http://logicblaze.com/