> Is ClientRequestor cheap to make each time? It's relatively cheap, but of course just about anything can be done enough to become expensive over time. Also, a ClientRequestor is not thread-safe so a single instance may be a bottleneck in your application. I don't know what your performance requirements are, how often you're making these calls, etc. so it's hard to provide any specific recommendations.
> One of my colleagues found that occasionally closing and re-creating the ClientRequestor avoids this problem, but I’d like to know why. I can't rightly say why you're seeing messages build up at this point. The screenshot shows that there's a consumer on both queues. Perhaps these consumers are no longer acknowledging the messages they receive. You say you're only using a single ClientRequestor instance but there's two queues which indicates two ClientRequestor instances working concurrently so perhaps you're leaking ClientRequestors at some point. Do you have a way to reproduce this? If so, could you create a reproducible test-case which I could use to see the same behavior? Justin On Mon, Jan 16, 2023 at 10:55 AM John Lilley <john.lil...@redpointglobal.com.invalid> wrote: > We do keep a singleton ClientRequestor around forever. Perhaps this is > just wrong? Is ClientRequestor cheap to make each time? > > > > One of my colleagues found that occasionally closing and re-creating the > ClientRequestor avoids this problem, but I’d like to know why. > > > > I think you can see that image here: > > > https://drive.google.com/file/d/1gKDrg4-tRs7WSPbsqQ7Bu-UfhBPu4Fdj/view?usp=sharing > > > > john > > > > > > > [image: rg] <https://www.redpointglobal.com/> > > John Lilley > > Data Management Chief Architect, Redpoint Global Inc. > > 888 Worcester Street, Suite 200 Wellesley, MA 02482 > > *M: *+1 7209385761 <+1%207209385761> | john.lil...@redpointglobal.com > > From: Justin Bertram <jbert...@apache.org> > *Sent:* Monday, January 16, 2023 9:48 AM > *To:* users@activemq.apache.org > *Subject:* Re: Messages accumulating in management queue > > > > **** [Caution] This email is from an external source. Please use caution > responding, opening attachments or clicking embedded links. **** > > > > > I don’t know if that image comes through the mailing list... > > > > I can't see your image. For what it's worth, attachments don't usually > make it through the list. > > > > Could you upload the image to another location and provide a link? > > > > Also, could you provide the full stack-trace of the NPE? > > > > I don't see in your code where you're actually closing the ClientRequestor > so that might be a problem. Without more details it's impossible to say. > > > > > > Justin > > > > On Mon, Jan 16, 2023 at 10:31 AM John Lilley < > john.lil...@redpointglobal.com.invalid> wrote: > > Greetings! > > > > We are using the Artemis queue-based management APIs, and noticed that one > of the two management queues that appears in the console starts to grow > without bound: > > > > > > I don’t know if that image comes through the mailing list, but it shows > two of the xn--activemq-2p3d.management > <https://linkprotect.cudasvc.com/url?a=https%3a%2f%2fxn--activemq-2p3d.management&c=E,1,yM5VuqjniGEfl7K4rM70Xa-2jC5pkpu2WMCuv2o_9ssgUAyqDzgAfPDtdn-xMCHxrbyaUxPnF2oUZkGoCF_o-vv_o42p3PRnI9YguDv7nT8RO5syVzebSQ,,&typo=1&ancr_add=1><UUID>” > queues, and one of the counts is in the 100s. It just keeps growing and > growing by about 300 per minute. > > > > I’ve tried to browse this queue on the management console, but the > browse() operation shows an NPE: > > java.lang.NullPointerException : Cannot invoke > "org.apache.activemq.artemis.core.paging.cursor.PageSubscription.iterator(boolean)" > because "this.this$0.pageSubscription" is null > > > > The calls we are making are like: > > String resourceName = ResourceNames.QUEUE + queueName; > > ClientRequestor client = getClient(); > > ClientSession clientSession = … > > ClientMessage request = clientSession.createMessage(false); > ManagementHelper.putAttribute(request, resourceName, attributeName); > ClientMessage reply = client.request(request); > > > > Or > > ClientRequestor client = getClient(); > > ClientMessage request = clientSession.createMessage(false); > ManagementHelper.putAttribute(request, resourceName, attributeName); > ClientMessage reply = client.request(request); > if (ManagementHelper.hasOperationSucceeded(reply)) { > for (var value : (Object[])ManagementHelper.getResult(reply, > Object.class)) { > result.add(value.toString()); > } > > > > Any idea what we are doing wrong? > > > > This happens on windows or linux > > > > Artemis version 2.27.0. > > > > java –version > > openjdk 17.0.3 2022-04-19 > > OpenJDK Runtime Environment Temurin-17.0.3+7 (build 17.0.3+7) > > OpenJDK 64-Bit Server VM Temurin-17.0.3+7 (build 17.0.3+7, mixed mode, > sharing) > > > > Thanks > > john > > > > > > [image: rg] > <https://linkprotect.cudasvc.com/url?a=https%3a%2f%2fwww.redpointglobal.com%2f&c=E,1,y0ymtXAc9XiBAplLMyDSTkbZPAR64gUyHhSGTjs8RK2_en31lUYrNYUf9Da_DM9WCm4_pRY8h4_s7PAUvD5SJfK1UCvi3Clxrot9XAr38A,,&typo=1> > > *John Lilley * > > *Data Management Chief Architect, Redpoint Global Inc. * > > 888 Worcester Street, Suite 200 Wellesley, MA 02482 > > *M: *+1 7209385761 <+1%207209385761> | john.lil...@redpointglobal.com > > > PLEASE NOTE: This e-mail from Redpoint Global Inc. 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