20k messages and 30k topics is quite a bit so I'm not surprised the CPU usage is very high. The reason the CPU is high after stopping the publishing is probably because you have a backlog on the broker that the consumers need to work off. You might also have a lot of messages being processed for the DLQ.
If you think the issue is related specifically to the redelivery plugin then your best bet is to hook up a profiler to the broker and to see where the hot spot is that is using the most CPU in the plugin. You can also trying using a thread dump to figure it out. On Thu, May 2, 2019 at 5:53 AM Franco Ng <franco...@ebshk.com> wrote: > No problem, I can provide heap dump but the file size is over 1GB. Please > provide location /link to upload, thanks. > > > > -- > Sent from: > http://activemq.2283324.n4.nabble.com/ActiveMQ-User-f2341805.html >