if you're facing some bug more specifically, i would ask you to produce a testcase and try it with a later version.
Perhaps what you need is a non durable queue, that would be removed when the connection is gone? On Tue, Jun 23, 2020 at 4:40 PM Clebert Suconic <[email protected]> wrote: > > Artemis doesn't impose a limit on the number of connections, but that > doesn't mean you shouldn't cleanup after your queues. > > You should probably manage the queue creation. if you are allowing > user's to create durable subscription, their subscriptions will be > available beyond your client life cycle. You should manage these > topics and queues. > > > On Wed, Jun 17, 2020 at 9:06 AM <[email protected]> wrote: > > > > Hi there, > > > > I’m using Artemis 2.6.3 as an MQTT broker embedded in a Spring 5 > > application with persistence enabled. I have not configured a limit for the > > number of connections or anything. > > > > One of our customers reported an issue when they subscribe to MQTT topics. > > To find the root cause, I create a a large number of clients in Java using > > Eclipse Paho, each with its own client ID. The clients connect with > > cleanSession=false to the broker and then subscribe to some topics. I found > > out that after about 140 client connections (actual number differs from > > test run to test run), new clients receive "java.io.IOException: Connection > > is lost.“ with reason 32109. After a few seconds, a few new clients can > > connect (around 10). When I terminate all connected clients without > > unsubscribing from the topics (basically I’m simulating a crash of the > > clients here), again only a few new clients (with client IDs not used so > > far) can connect before receiving the IOException. Reconnecting the 140 > > clients with their original client ID is no problem. > > > > Looking into the logs, I see the following message for each client and each > > topic the client subscribed to: > > 2020-06-17 12:39:15,446 [Thread-27 > > (ActiveMQ-server-org.apache.activemq.artemis.core.server.impl.ActiveMQServerImpl$5@6ef80f24)] > > DEBUG o.a.a.a.core.server.impl.QueueImpl - Scanning for expires on > > client-96.base-topic.*.topic > > The "Scanning for expires“ is triggered every 30 seconds, so I see hundreds > > of these messages in the log every 30 seconds. These messages keep coming > > for hours (maybe forever), even for the „creashed“ clients. This seems to > > me that our customers will sooner or later run into problems when they have > > a large number of clients that crash from time to time. In particular, if > > they do not reuse the client IDs. > > > > From reading the documentation > > (https://activemq.apache.org/components/artemis/documentation/1.0.0/resource-limits.html), > > I would expect that the number of connections is not limited. > > > > So I have two issues where I would appreciate any help: > > 1. Why is the number of connections limited in my scenario? > > 2. How can my broker get rid of the „dead" bindings of the „crashed“ > > clients? > > > > Thanks a lot > > Tobias > > > > -- > Clebert Suconic -- Clebert Suconic
