High CPU utilization when using an ActiveMQ failover url with priorityBackup=true

Solution Unverified - Updated -


  • JBoss A-MQ 6.0


When JMS clients are configured to use the failover transport in conjunction with priorityBackup=true the CPU utilization goes up immediately.
Removing priorityBackup from the failover url resumes cpu utilization back to normal.


In the particular case where this problem had occurred it was caused by the client using the nio:// transport in the failover url.
So a url similar to this was used:


The use of the nio transport is only for configuring the broker's transport connector. Its a server side transport only. Its not meant to be used by JMS client applications.
Changing the url to use tcp instead of nio


resolved the problem.

Root Cause

The nio transport should not be used by JMS client applications. The high cpu utilization may not be observed on every system when combining nio and priorityBackup=true in the failover url.

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