thanks, there is another question: I can I make sure a task is
processed once and only once?
do I need do like this:
onMessage(){
if(msg.getJMSRedelivered()){
//check some central status system such as database to see whether
it's finished
//if finished
return;
else //partial done
undo partial work
do real work
}else{
do real work
}
On Mon, Feb 24, 2014 at 10:55 PM, Yin Wang <[email protected]> wrote:
> Seems what you really want to solve is to distribute real task messages
> evenly between consumers.
> As default a consumer has a prefetch to allow broker to push messages to it
> in batch manner,
> if a consumer is slow to process message then many pending messages will be
> accumulated
> and other consumers may suffer starvation.In this case those real tasks
> wont get executed in time.
> You can just use pull mechanism for your consumers so that your consumer
> can pull real task message from broker one by one.
> Fast consumers can have a chance to pull more messages than slow consumers.
> If consumers still can not process real tasks in time, increase consumers
> or tune performance for consumers.
>
>
> 2014-02-24 19:07 GMT+08:00 Li Li <[email protected]>:
>
>> I've read the jms specification and questions by google such as
>>
>> http://stackoverflow.com/questions/2991412/anyone-know-exactly-which-jms-messages-will-be-redelivered-in-client-acknowledge
>> . But I still confused about it.
>> Another question is: how can a consumer tell the broker to
>> redelevery a message to other consumers(maybe again to this consumer)
>> e.g. we have some real time tasks and here is code:
>> class MyConsumer implements MessageListener{
>>
>> public void onMessage(Message msg) {
>> doPhrase1();
>> if(leftTime < avgTime1){
>> //Tell broker I can't finish it in time,
>> //you should redelevery to other consumers
>> //do some cleanup job
>> }
>> doPhrase2();
>> if(leftTime < avgTime1){
>> //Tell broker I can't finish it in time,
>> //you should redelevery to other consumers
>> //do some cleanup job
>> }
>> doPhrase3();
>> }
>>
