As far as I can tell this is the same message you sent a few days ago. You can find my response to that message here [1].
Justin [1] https://lists.apache.org/thread/p2lxw22nhwhq015lvjn0kqtxdsdj3vx4 On Tue, Jan 3, 2023 at 7:13 PM John Lilley <john.lil...@redpointglobal.com.invalid> wrote: > Greetings! > > > > In our app, we have a lot of batch “jobs”, each of which stands up an RPC > service on a unique queue. However, when jobs quit, clients may still try > to communicate and I don’t want this to hang, I want clients to see an > error reply. To this end, I am implementing a “fallback” service for > ended-job RPC queues, of which there can be 100s, that returns errors. > This is expected to be very low traffic and the polling can be done > infrequently (like every few seconds), so performance doesn’t matter. > > > > The queues are set to auto-delete, and in order to keep broker memory > down, I don’t want to do anything to prevent auto-deletion. Because in > most cases, nothing will be posted to these queues. I want to use a > strategy like this: > > • Enumerate queues first, to see which ones exist. > > • Of the queues that exist, use the queue-based management API > to get a message count (see method below). > > • Only for queues that have a non-zero message count, create a > consumer and call receive() to poll for messages. > > > > Will this strategy avoid interfering with the broker’s auto-delete? > > Is queue enumeration low-impact enough to call it every few seconds? > > > > Method used for getting queue count (this is all using the > artemis-jms-client-all JMS client): > > > > public int getQueueEntryCount(String queueName) { > > return getIntAttribute(queueName, "MessageCount"); > > } > > > > private int getIntAttribute(final String queueName, final String > attributeName) { > > String resourceName = ResourceNames.QUEUE + queueName; > > synchronized (lock) { > > ClientRequestor client = getClient(); > > try { > > ClientMessage request = clientSession.createMessage(false); > > ManagementHelper.putAttribute(request, resourceName, attributeName); > > ClientMessage reply = client.request(request); > > if (ManagementHelper.hasOperationSucceeded(reply)) { > > return (int)(long)ManagementHelper.getResult(reply, Long.class); > > } else { > > // Because we cannot tell the difference between > queue-does-not-exist and a real error > > return 0; > > } > > } > > catch (Exception e) { > > throw new RuntimeException("Error fetching " + attributeName + " for > queue " + queueName, e); > > } > > } > > } > > > > Thanks > > 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 > > PLEASE NOTE: This e-mail from Redpoint Global Inc. (“Redpoint”) is > confidential and is intended solely for the use of the individual(s) to > whom it is addressed. If you believe you received this e-mail in error, > please notify the sender immediately, delete the e-mail from your computer > and do not copy, print or disclose it to anyone else. If you properly > received this e-mail as a customer, partner or vendor of Redpoint, you > should maintain its contents in confidence subject to the terms and > conditions of your agreement(s) with Redpoint. >
