2.6. Vertical Scaling

Vertical scaling refers to the capacity of a single broker to support large numbers of connections from consumers and producers.

You can exploit the following tricks to optimize vertical scaling in Red Hat JBoss A-MQ:

NIO transport on the broker—to reduce the number of threads required, use the NIO transport (instead of the TCP transport) when defining transport connectors in the broker. Do not use the NIO transport in clients, it is only meant to be used in the broker.
Allocate more memory to broker—to increase the amount of memory available to the broker, pass the -Xmx option to the JVM.
Reduce initial thread stack size—to allocate a smaller initial stack size for threads, pass the -Xss option to the JVM.