Wiki > The Backend System > System components > ActiveMQ

ActiveMQ is a messaging broker that is used in a number of places throughout IBEX. Specifically it is used by:

• The Alarm Server
• The IOC Log Server

The GUI also hooks into ActiveMQ to read/write to all these components. Previously a version of ActiveMQ was bundled with each of these backend components. However, this was modified to be a single instance that is run through procserv when the instrument is first started.

Changing the ActiveMQ ports

The default ActiveMQ ports are:

• 39990 for the openwire protocol (used by JMS)
• 39991 for the STOMP protocol (used by script server)

Due to port conflicts these have been changed to those listed here.

The ports used are hardcoded in a number of places so to change them they must be changed in:

• EPICS\ISIS\ActiveMQ\master\conf\activemq.xml
• EPICS\CSS\master\AlarmServer\alarm_server_settings.ini
• EPICS\ISIS\IocLogServer\master\logserver_config.ini
• Client\base\uk.ac.stfc.isis.ibex.product\plugin_customization.ini
• Client\base\uk.ac.stfc.isis.ibex.activemq\src\uk\ac\stfc\isis\ibex\activemq\ActiveMQ.java

It's hard to put these into a central macro as most of the configuration requires loading *.ini files.