Currently, thread pool size can not be adjusted without server reload. If server runs into performance problem caused by thread pool size, there is no way to adjust thread pool size without termination of all running tasks. Making this configurable "on fly" would prevent this scenario.

Attribute thread-pool-max-size in /subsystem=messaging-activemq/server=default requires server reload.

Size of global client thread pools can be set only before this thread pool is created. Adjusting values of system properties which configure client thread pool size has no effect on running server (with pool already created).