You mean you are sending a PR or you will use null instead of “”?

On Sat, Aug 12, 2023 at 11:11 AM Jan Šmucr <jan.sm...@aimtecglobal.com>
wrote:

> Ok, I'll fix it then. My Jira at work will be happy for another Done task.
> 😁
>
> Jan
>
> Zasláno z Outlooku pro Android<https://aka.ms/AAb9ysg>
> ________________________________
> From: Clebert Suconic <clebert.suco...@gmail.com>
> Sent: Saturday, August 12, 2023 5:05:49 PM
> To: users@activemq.apache.org <users@activemq.apache.org>
> Subject: Re: Hunting memory leaks
>
> Just for a future reference, this is where the JMS layer protects this
> from happening:
>
>
> https://github.com/apache/activemq-artemis/blob/064018a3e9a1ba39ddbee0bbddfed3e7fccab89c/artemis-jms-client/src/main/java/org/apache/activemq/artemis/jms/client/ActiveMQSession.java#L592-L594
>
> On Sat, Aug 12, 2023 at 11:03 AM Clebert Suconic
> <clebert.suco...@gmail.com> wrote:
> >
> > This only happened because you used the Core API directly, and passed
> > a "" as the filter String.
> >
> >
> > In the JMS layer, there's a check to replace "" by null and that would
> > leave that out.
> >
> > there's a check to add and remove existing filters from the
> > selectors.. but in your case this is creating a leak of "" strings.
> >
> >
> >
> > You should instead pass in null instead of "" for now.
> >
> >
> > We could add a layer of protection on the client and on the server
> > replacing "" by null both client and server.
> >
> >
> > As for a test... We could add a test under ./tests/leak-tests...
> > counting the number of SimpleStrings with CheckLeak (look at other
> > tests) and then making sure it won't go beyond a certain limit.
> >
> >
> > (Do you want to send the PR yourself?)
> >
> >
> >
> > I'm not going to rush for a fix now as you can just use null instead
> > of "" on your filter string and this leak won't happen (I already
> > tested it).
> >
> >
> > let me know if you want to send the PR.. as I don't want to duplicate
> > your efforts. If you're not fixing it just let me know and I will do
> > it on monday.
> >
> >
> > Thanks for this !
> >
> > On Sat, Aug 12, 2023 at 10:53 AM Jan Šmucr <jan.sm...@aimtecglobal.com>
> wrote:
> > >
> > > I'll leave it up to you. If you're busy, I'll have created a PR by
> Monday too. 🙂 And as a bonus, I'll get better acquaintanted with the
> Artemis code.
> > >
> > > Jan
> > >
> > > ________________________________
> > > Od: Clebert Suconic <clebert.suco...@gmail.com>
> > > Odesláno: sobota, srpna 12, 2023 4:48:08 odp.
> > > Komu: users@activemq.apache.org <users@activemq.apache.org>
> > > Předmět: Re: Hunting memory leaks
> > >
> > > The leak is because you are creating a consumer within the same
> > > session over and over:
> > >
> > >
> https://github.com/apache/activemq-artemis/blob/064018a3e9a1ba39ddbee0bbddfed3e7fccab89c/artemis-server/src/main/java/org/apache/activemq/artemis/core/postoffice/impl/PostOfficeImpl.java#L410-L420
> > >
> > >
> > > Do you want to raise the JIRA for this? I should have a fix by monday.
> > >
> > >
> > > If you keep your consumer open instead of open  / close it all the
> > > time this won't happen.  But I should have a fix by monday.
> > >
> > > On Fri, Aug 11, 2023 at 12:24 PM Clebert Suconic
> > > <clebert.suco...@gmail.com> wrote:
> > > >
> > > > I highly recommend you using check-leak.. you would have found what's
> > > > leaking already.
> > > >
> > > > https://github.com/check-leak/check-leak
> > > >
> > > > java -jar check-leak-0.10.jar remote --pid <PID> --report
> > > > <reportoutput> --sleep 5000
> > > >
> > > > ( I suggest using 5 seconds for your test)
> > > >
> > > >
> > > >
> > > > I would even write a unit-test for memory-leaks.
> > > >
> > > > On Fri, Aug 11, 2023 at 10:06 AM Jan Šmucr <
> jan.sm...@aimtecglobal.com> wrote:
> > > > >
> > > > > So I’m getting a bit closer. The leak is in PostOfficeImpl and
> QueueInfo. QueueInfo contains the filterStrings List which appears to
> contain a list of filters used by consumers subscribed to that queue.
> However, for some reason this list is updated in a very strange way. For
> one or two consumers there are no CONSUMER_CREATED and CONSUMER_CLOSED core
> notifications which PostOfficeImpl would receive and update the list
> accordingly (also managing the list from outside of QueueInfo is quite
> weird).
> > > > > From the 3rd consumer the management messages start flowing, and
> here comes the catch: The CONSUMER_CREATED message contains
> _AMQ_FilterString = "" whereas the CONSUMER_CLOSED message contains
> AMQ_FilterString = null. So the filterStrings List keeps filling up by
> empty strings because these don’t get removed based on a null value.
> > > > >
> > > > > Jan
> > > > >
> > > > > From: Jan Šmucr<mailto:jan.sm...@aimtecglobal.com>
> > > > > Sent: pátek 11. srpna 2023 9:43
> > > > > To: users@activemq.apache.org<mailto:users@activemq.apache.org>
> > > > > Subject: RE: Hunting memory leaks
> > > > >
> > > > > Hello all.
> > > > >
> > > > > I know it’s not ideal but the broker is doing just fine (except
> for the leak issue of course).
> > > > >
> > > > > I’ve tried upgrading to 2.30.0 and the broker still ends up on its
> knees given enough load and only a little heap. In my testing case I’ve
> limited the heap size to 64 MiB so that I wouldn't have to wait for days
> for things to happen, and also the consumer creation/disposal rate is
> different to the production state. Here’s a very simple code which manages
> to take down the 64 MiB broker in about 10 to 15 minutes on Java 11 and
> recent Windows 10:
> > > > >
> > > > > final String queueName = "clouedi-kestra";
> > > > > final String filter = "";
> > > > > final Thread[] threads = new Thread[16];
> > > > > for (int i = 0; i < threads.length; i++) {
> > > > >     threads[i] = new Thread(() -> {
> > > > >         try (
> > > > >                 ServerLocator locator =
> ActiveMQClient.createServerLocator("tcp://localhost:61616");
> > > > >                 ClientSessionFactory sf =
> locator.createSessionFactory();
> > > > >                 ClientSession session = sf.createSession(false,
> true);
> > > > >         ) {
> > > > >             while (!session.isClosed()) {
> > > > >                 try (ClientConsumer consumer =
> session.createConsumer(SimpleString.toSimpleString(queueName),
> SimpleString.toSimpleString(filter), 0, 0, false)) {
> > > > >                     consumer.receive(1);
> > > > >                 }
> > > > >             }
> > > > >         } catch (Exception e) {
> > > > >             throw new RuntimeException(e);
> > > > >         }
> > > > >     });
> > > > >     threads[i].start();
> > > > > }
> > > > > for (Thread thread : threads) {
> > > > >     thread.join();
> > > > > }
> > > > >
> > > > > Big thanks for your help!
> > > > > Jan
> > > > >
> > > > > From: Arthur Naseef<mailto:a...@amlinv.com>
> > > > > Sent: čtvrtek 10. srpna 2023 21:11
> > > > > To: users@activemq.apache.org<mailto:users@activemq.apache.org>
> > > > > Subject: Re: Hunting memory leaks
> > > > >
> > > > > Creating a consumer only to consume 1 message is not ideal -
> there's a lot
> > > > > of overhead and work on the broker side when consumers are created.
> > > > >
> > > > > With that said, since the consumer should be getting closed
> properly, that
> > > > > should not cause a leak.
> > > > >
> > > > > So first, I would prioritize the version update.  Second, I would
> consider
> > > > > changing the use of consumers so they are longer-lived -
> preferrably only
> > > > > being removed once the application needs to stop consuming.
> > > > >
> > > > > If there is a need to throttle and/or control threading and
> parallel
> > > > > processing of messages, perhaps Camel would be a good fit.
> > > > >
> > > > > Hope this helps.
> > > > >
> > > > > Art
> > > > >
> > > > >
> > > > > On Wed, Aug 9, 2023 at 10:44 PM Jan Šmucr <
> jan.sm...@aimtecglobal.com>
> > > > > wrote:
> > > > >
> > > > > > Hello all. Thank you for your insights.
> > > > > >
> > > > > >
> > > > > >   *   I’m using the core Java library.
> > > > > >
> > > > > >
> > > > > >   *   Consumers are being created once per poll but reused if
> there are
> > > > > > multiple inbound files to deal with. I create consumers like
> > > > > >
> > > > > > try (final consumer = createConsumer(session, params)) {
> > > > > >
> > > > > >    // ...
> > > > > > }
> > > > > >
> > > > > > so I expect them to be closed automatically.
> > > > > >
> > > > > >
> > > > > >   *   I don’t use JMS, but the core sessions are used one per
> thread. The
> > > > > > number of sessions opened and reported by Artemis doesn’t change
> over time.
> > > > > >
> > > > > >
> > > > > >   *   I cannot reproduce the issue yet. It’s a production
> cluster, so
> > > > > > today I’m going to set up my own playground.
> > > > > >
> > > > > >
> > > > > > Jan
> > > > > >
> > > > > > From: Justin Bertram<mailto:jbert...@apache.org>
> > > > > > Sent: středa 9. srpna 2023 17:41
> > > > > > To: users@activemq.apache.org<mailto:users@activemq.apache.org>
> > > > > > Subject: Re: Hunting memory leaks
> > > > > >
> > > > > > I echo Tim's recommendation to use the latest release, but I
> don't mean to
> > > > > > say that will certainly resolve the problem.
> > > > > >
> > > > > > I can't say if you're doing anything wrong without more
> information. Can
> > > > > > you answer the following questions?
> > > > > >
> > > > > >  - What client library are you using?
> > > > > >  - How often are consumers being created?
> > > > > >  - Are consumers being closed properly once they are no longer
> needed?
> > > > > >  - Are JMS sessions being used concurrently from multiple
> threads?
> > > > > >  - Do you have a way to reproduce this that you can provide to
> me? A
> > > > > > reproducer would make diagnosing this issue much simpler.
> > > > > >
> > > > > > Entries to the list of filter strings are added when a consumer
> is created
> > > > > > and removed when a consumer is closed so at first glance it
> appears you're
> > > > > > leaking consumers.
> > > > > >
> > > > > >
> > > > > > Justin
> > > > > >
> > > > > > On Wed, Aug 9, 2023 at 7:07 AM Jan Šmucr <
> jan.sm...@aimtecglobal.com>
> > > > > > wrote:
> > > > > >
> > > > > > > Hello.
> > > > > > > I’m using a simple master-slave Artemis 2.26.0 cluster, and
> I’m noticing
> > > > > > > heap usage growing more and more each day no matter the
> throughput.
> > > > > > There’s
> > > > > > > about 670 sessions at the same time opened for producers and
> consumers.
> > > > > > > Consumers are polling queues on regular basis, some once a
> second
> > > > > > (meaning
> > > > > > > 1s timeout), some less often. This is by design and cannot be
> altered.
> > > > > > All
> > > > > > > client resources are being reused as much as possible. Usually
> there’s a
> > > > > > > thread pool and the threads have a session opened, and wait
> for tasks to
> > > > > > be
> > > > > > > available to them.
> > > > > > > It appears to me that the more consumers there is the faster
> the server
> > > > > > > heap depletes.
> > > > > > > Now, I’m not very familiar with leak hunting apps, so all I
> have are tiny
> > > > > > > hints that it may have something to do with filter strings not
> being
> > > > > > reused
> > > > > > > and/or thrown away when not needed any more. I don’t know if I
> can post a
> > > > > > > screenshot here so I uploaded it here:
> https://snipboard.io/LHifUK.jpg
> > > > > > > This is from a heap dump opened in JMC JOverflow plugin.
> > > > > > > Is there something obvious that I’m doing wrong? Do you have
> any clues on
> > > > > > > what is going on here?
> > > > > > > Thank you.
> > > > > > > Jan.
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > >
> > > >
> > > > --
> > > > Clebert Suconic
> > >
> > >
> > >
> > > --
> > > Clebert Suconic
> > >
> >
> >
> > --
> > Clebert Suconic
>
>
>
> --
> Clebert Suconic
>
-- 
Clebert Suconic

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