Nagios-ActiveMQ binding configuration details

Table of Contents

No need for habit changes !

The related configuration script has been written in a way to feed from existing definition files to build ActiveMQs configuration. Of course you need to provide some specific information, but you don't need to change anything in older configuration habits (ie. you define message handlers in the same way as before). Furthermore, you can very easily customise the new configuration file as it is YAML formated.

Check the diagrams to get a picture of how the new configuration is built.

Author : JulienPerrochet - 2009-08-28

ActiveMQ : activemq-configure.sh

Call this script when you have set everything in the configuration files. A sub-script will generate the activemq.xml configuration file and it will then move it to /etc/activemq/activemq.xml. The called subscript is activemq-gen-config.pl. It will feed from the following files to generate ActiveMQs configuration. A precise description of each file can be found below.

Once the new file has been generated, ActiveMQ has to be restarted. This is generally done by $ service activemq restart . If ActiveMQ refuses to start, it can be a sign that something is wrong inside the configuration file.

Files

• configs/activemq_raw_xml.xml The model for the ActiveMQ configuration file. It holds some static configurations and variables that will be replaced during parsing.
• configs/activemq-configurator.cfg Some variables that will be put into the ActiveMQ configuration file can be set here.
• /etc/msg-to-queue/msg-to-queue.conf This file holds the definitions of the message handlers. Part of the variables in the raw configuration file will be determined by the content of these files.

File Descriptions

configs/activemq_raw_xml.xml

This is a basic ActiveMQ XML configuration file. It already has the correct structure to fit ActiveMQs needs, but holds some variables that are defined with the following syntax :

V<variable_name>

See the activemq_raw_xml.xml sample files to get an idea.

configs/activemq-configurator.cfg

This is a YAML formatted configuration file that holds variables such as the backbone broker address.

You fix variables in an easy =variable : 'value' = fashion.

Look at the activemq-configurator.cfg sample file and to the YAML website if you want to know more about it : http://www.yaml.org/

/etc/msg-to-queue/msg-to-queue.conf

Here are the definitions for the message handlers. You can also put an include statement in it, and anything included will be loaded as well. Just check a sample definition to get an idea : msg-to-queue.conf

msg-to-handler (formerly msg-to-queue) old and new scheme

Backbone Bridging

Queues and topics from the backbone are all bridged to separate local queues on the local broker. Any wildcard character " * " or " > " will be replaced by " WC " in the local queue. So, for example, if the following have to be subscribed to on the backbone :

• /queue/probe.job.return
• /topic/global.*.output
• /topic/global.>

They will be bridged to the following on the local broker :

• /queue/probe.job.return
• /queue/global.WC.output
• /queue/global.WC

Basically, topics and queues become only topics on the local broker.

Images

• Previous local incoming message architecture:
  

• New local incoming message architecture: