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Date: Wed, 17 Apr 2013 09:08:33 -0700
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 <CAKS7T5ND0wfPqcteOJFR9HPS9Vrh=qTmwtMLuEUfzCdc5RvxFA@mail.gmail.com>
Subject: Re: What can be reason of 460%+ memory usage limit
From: Christian Posta <christian.posta@gmail.com>
To: "users@activemq.apache.org" <users@activemq.apache.org>
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Check the dispatch method in Topic.java... we do just that:

            synchronized (consumers) {
                if (consumers.isEmpty()) {
                    onMessageWithNoConsumers(context, message);
                    return;
                }
            }

onMessageWithNoConsumers really just sends advisories for specific cases


On Sun, Apr 7, 2013 at 7:24 AM, SuoNayi <suonayi2006@163.com> wrote:

> Hi,we're using the virtual topic to scatter messages to 12
> queues/consumers.
>
> When one consumer of one queue becomes very slow since it's located in
> London,
> far from our data center in china, our single producer becomes very slow
> to publish messages.
> What phenomenon we observed is that:
> When the slow consumer located in London dequeues 200 messages the single
> producer can publish 200 messages or it will be blocked.
> It seems that PFC is working but I ensure I have disabled PFC for queues
> when the broker is deployed in production.
> But PFC for topics is enabled and I have make that disabled and given the
> broker a reboot.
> After that my producer can keep publishing messages regardless of the slow
> consumer but the memory usage limit keeps increasing all the time.
> Eventually I saw the 460+ memory usage limit reached which made me very
> surprised.
> AFAIK, the pending messages in transactions can contribute to the exceeded
> memory usage limit.
> Since we only have single producer and we send 100 messages in a batch
> using a transaction and every message size is less than 1kb,
> So I can not understand how the  memory usage limit exceeds so much.
>
>
> Thanks,
> SuoNayi


-- 
*Christian Posta*
http://www.christianposta.com/blog
twitter: @christianposta

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