ActiveMQ Nagios Plugin

Monitor Apache ActiveMQ's health, queuesizes and subscribers. The plugin makes use of the Jolokia REST interface.

Requirements (tested with):

• ActiveMQ starting from version 5.8
• Python 2.7
• nagiosplugin 1.2.2

nagiosplugin is a Python Framework designed for Nagios Plugins written in Python. It can be installed via pip.

Supported ActiveMQ Versions

The plugin queries ActiveMQ using the new REST based Jolokia interface.

ActiveMQ < 5.8

To use this plugin with an ActiveMQ version earlier than 5.8 you have too add Jolokia support manually.

ActiveMQ < 5.9.1

With version 5.9.1 of ActiveMQ, the Hawtio console was removed. If you run a version of ActiveMQ that still includes Hawtio, you need to supply the --url-tail "hawtio/jolokia/read" parameter to the plugin.

For releases without Hawtio, this paramter can be omitted and defaults to api/jolokia/read.

Installation

1. Navigate to the folder where your nagios plugins are stored e.g.:
   • cd /usr/lib/nagios/plugins/
   • Download the plugin script:
   • wget https://raw.githubusercontent.com/predic8/activemq-nagios-plugin/master/check_activemq.py
   • Install nagiosplugin for Python:
   • pip install nagiosplugin (systemwide, execute as root) or
   • pip install --user nagiosplugin (for the current user)

Command line options:

• Run ./check_activemq.py -h to see the full (and up to date) help
• --host specifies the Hostname of the ActiveMQ broker
• --port specifies the Port
• --user specifies the Username of ActiveMQ's Web Console
• --pwd specifies the Password

Checks

This Plugin currently support 4 different checks listed below. All checks return UNKNOWN if the broker isn't reachable on the network.

queuesize

• Check the size of one or more Queues.
• Additional parameters:
  • -w WARN specifies the Warning threshold (default 10)
  • -c CRIT specifies the Critical threshold (default 100)
  • QUEUE - specify queue name to check (see additional explanations below)
• If queuesize is called with NO queue parameter then ALL queues are checked (excluding queues whose name start with 'ActiveMQ').
• If queuesize is called WITH a queue then this explicit queue name is checked.
  • A given queue name can also contain shell-like wildcards like * and ?

health

• Checks the overall health of the broker.
• Returns OK or WARN.

subscriber

• Checks if the specified clientId is a subscriber of the specified topic and raises a Warning if this isn't the case.
• Additional parameters:
  • --clientId specifies a client ID
  • --topic specifies a topic of the ActiveMQ Broker
• Returns CRITICAL if the given Topic does not exist / has no subscribers / the clientId is invalid.
• Returns WARN if the given clientId is an inactive Subscriber.

exists

• Checks if a Queue or a Topic with the specified name exists.
• Additional parameters:
  • --name specifies a Queue or Topic name
• Returns Critical if no Queue or Topic with the given name exist.

subscriber_pending

• Checks the Pending Queue Size and the clientId for a given subscription.
• Additional parameters:
  • --subscription specifies the name of a subscription
  • --clientId specifies a client ID
• Returns Critical if clientId is not the Client Id of the given subscription.

dlq

• Check if there are new messages in a DLQ (Dead Letter Queue).
• Additional parameters:
  • --prefix PREFIX - specify DLQ prefix, all queues with a matching prefix will be checked (default 'ActiveMQ.DLQ.')
  • --cachedir CACHEDIR - specify base directory for state file (default '~/.cache')
• Returns Unknown if no Queues with the specified PREFIX were found.
• Returns Critical if one of the Queues with a matching prefix contains more messages since the last check.
• This mode saves it's state in the file CACHEDIR/activemq-nagios-plugin/dlq-cache.json
• When you want to use this check, it is recommended that you invoke the plugin rather often from Nagios (e.g. every minute or every 30 seconds) to have a better coverage of your ActiveMQ's state.
• Note (this might lead to confusion): When the plugin yields a message for a specific queue (e.g. 'No additional messages in ActiveMQ.DLQ.Test'=0) the =0 means that there are 0 additional messages since the last check, it does NOT mean that there are 0 messages in the queue. (Use queuesize if you want to check this.)

Examples. Check

• the queue size of the queue TEST
  • ./check_activemq.py queuesize TEST
• the queue sizes of all queues starting with TEST
  • ./check_activemq.py -w 30 -c 100 queuesize "TEST*"
• the overall health of the ActiveMQ Broker
  • ./check_activemq.py health
• that Spongebob is a subscriber of BikiniBottom
  • ./check_activemq.py subscriber --clientId Spongebob --topic BikiniBottom
• if a queue or a topic with a given name exists
  • ./check_activemq.py exists --name someQueueName
  • ./check_activemq.py exists --name someTopicName
• if there are new messages in the Dead Letter Queue
  • ./check_activemq.py dlq --prefix 'DLQ.''