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h1. Monitoring the Petals SE ASE

{tip}In this version of the Petals ASE, the monitoring is based mainly on the ActiveMQ monitoring.{tip}

The following indicators are interesting:
* number of requests processed with fault in the persistence area: a fast increase of this value should show:
** the target service provider or its backend are overloaded or down,
** a DoD of the ASE service provider client
* number of retried requests: an increase of this value should show:
** the target service provider or its backend are overloaded or down,
** the ASE service provider client doesn't respect the SLA
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h2. Monitoring with basic tools

{tip}The command-lines and configuration files mentionned in following sub-chapters are available on Ubuntu 11.10{tip}


h3. JVisualVM

As ActiveMQ is provided with a JMX API, it is very easy to connect the JVisualVM to the ActiveMQ's JVM. See [http://activemq.apache.org/jmx.html].
{info}Don't forget to install into JVisualVM its plugin *VisualVM-MBeans* previously.{info}

h3. Command line tools of ActiveMQ

ActiveMQ is provided with a command-line tools to get statistics: {{activemq-admin}}

For example, use the following command to get the number of the requests waiting to be sent to the target service provider:
{code}activemq-admin query --objname Type=Queue,Destination=testQueue --view QueueSize | grep QueueSize{code}

h2. Monitoring with Nagios

Several options are available to monitor ActiveMQ using Naggios:
* Integrating Munin with Naggios, sending messages from Munin to Naggios: [http://munin-monitoring.org/wiki/HowToContactNagios]
* Integrating Munin with Naggios, using Naggios active checks: [http://exchange.nagios.org/directory/Plugins/Uncategorized/Operating-Systems/Linux/check_munin_rrd/details]
* Integrating ActiveMQ with Naggios, using ActiveMQ's command-line tools: {color:#ff0000}{*}TODO{*}{color}

{tip}Solution based on an [article of R.I.Pienaar|http://www.devco.net/archives/2010/07/25/monitoring_activemq.php]

{tip}

h2. Monitoring with Munin

A plugin ActiveMQ for Munin exists: [http://munin-activemq.sourceforge.net]. It is very easy to install it on a Debian-based system using the Debian package. Don't forget to install Munin previously.
The downloaded package can be installed with the followinf command: {code}sudo dpkg -i munin-java-activemq-plugins_0.0.4_i386.deb{code}

h3. Pre-requisites

The plugin ActiveMQ for Munin requires a remote JMX connection to the ActiveMQ server, so you needs to configure your ActiveMQ to enable the JMX connector:

{code}<beans ... >
<broker xmlns="http://activemq.apache.org/schema/core" ... >
...
<managementContext>
<managementContext createConnector="true"/>
</managementContext>
...
</broker>
...
</beans>{code}

h3. Configuration

Edit the file {{/etc/munin/plugin-conf.d/activemq\_}} to add the queues to monitor in parameter {{env.DESTINATIONS}} of the section ?{{activemq\*}}. :

{code:none}
[activemq_*]
## The hostname to connect to.
## Default: localhost
#env.JMX_HOST localhost

## The port where the JMX server is listening
## Default: 1099
#env.JMX_PORT 1099

## The username required to authenticate to the JMX server.
## When enabling JMX for a plain ActiveMQ install, no authentication is needed.
## The default username for JMX run by ServiceMix is 'smx'
## Default:
#env.JMX_USER smx

## The password required to authenticate to the JMX server.
## The default password for JMX run by ServiceMix is 'smx'
## Default:
#env.JMX_PASS smx

## Space separated list of destinations to create graphs for.
## Default:
env.DESTINATIONS Queue:foo Queue:bar

## You can override certain configuration variables for specific plugins
#[activemq_traffic]
#env.DESTINATIONS Topic:MyTopic Queue:foo
{code}

h3. Integrating Munin with Naggios using Naggios active checks

{tip}This chapter is based on information available [here|http://exchange.nagios.org/directory/Plugins/Uncategorized/Operating-Systems/Linux/check_munin_rrd/details]{tip}

h4. Installation of the Nagios plugin for Munin

On your Nagios host:
# Download the Perl script {{[check_munin_rdd.pl|http://exchange.nagios.org/components/com_mtree/attachment.php?link_id=1168&cf_id=24]}} into the Nagios plugins directory (under Ubuntu: {{/usr/lib/nagios/plugins}}),
# Check that the owner file and permissions are the same as other ones (root, and 755). Fix them if needed.

h4. Nagios commands definition to interact with a Munin agent

A specific Nagios command to interact with Munin agent must be defined on your Nagios host:
# create the file {{munin.cfg}} in the directory {{/etc/nagios-plugins/config}} (except for Ubuntu, adapt the directory name to your operating system).
# check that the owner file and permissions are the same as other ones (root, and 644). Fix them if needed.
# edit the previous file with the following content:
{code}
define command{
command_name check_munin
command_line /usr/lib/nagios/plugins/check_munin_rrd.pl -H $HOSTALIAS$ -M $ARG1$ -w $ARG2$ -c $ARG3$
}
{code}

h4. Nagios template service to interact with a Munin agent

A specific template service to interact with Munin agent must be defined on your Nagios host:
# create the file {{generic-munin-service.cfg}} in the directory {{/etc/nagios3/conf.d}} (except for Ubuntu, adapt the directory name to your operating system).
# check that the owner file and permissions are the same as other ones (root, and 644). Fix them if needed.
# edit the previous file with the following content:
{code}
define service{
name generic-munin-service ; The 'name' of this service template
active_checks_enabled 1 ; Active service checks are enabled
passive_checks_enabled 0 ; Passive service checks are enabled/accepted
parallelize_check 1 ; Active service checks should be parallelized (disabling this can lead to major performance problems)
obsess_over_service 1 ; We should obsess over this service (if necessary)
check_freshness 0 ; Default is to NOT check service 'freshness'
notifications_enabled 1 ; Service notifications are enabled
event_handler_enabled 1 ; Service event handler is enabled
flap_detection_enabled 1 ; Flap detection is enabled
failure_prediction_enabled 1 ; Failure prediction is enabled
process_perf_data 1 ; Process performance data
retain_status_information 1 ; Retain status information across program restarts
retain_nonstatus_information 1 ; Retain non-status information across program restarts
notification_interval 0 ; Only send notifications on status change by default.
is_volatile 0
check_period 24x7
normal_check_interval 5 ; This directive is used to define the number of "time units" to wait before scheduling the next "regular" check of the service.
retry_check_interval 3 ; This directive is used to define the number of "time units" to wait before scheduling a re-check of the service.
max_check_attempts 2 ; This directive is used to define the number of times that Nagios will retry the service check command if it returns any state other than an OK state. Setting this value to 1 will cause Nagios to generate an alert without retrying the service check again.
notification_period 24x7
notification_options w,u,c,r
contact_groups admins
register 0 ; DONT REGISTER THIS DEFINITION - ITS NOT A REAL SERVICE, JUST A TEMPLATE!
}
{code}

h4. Define ActiveMQ check as service of a Petals node

{tip}See [petalsesbsnapshot:Monitoring Petals ESB with Nagios] to configure Nagios to monitor Petals ESB{tip}

In main use-cases, the ActiveMQ server is collocated with the Petals ESB node running the SE ASE. So, it is a good practice to define ActiveMQ as a service of the Petals node running the SE ASE:
# edit the Nagios configuration file of your Petals ESB node (for example: {{/etc/nagios3/conf.d/petals-esb-host-node1.cfg}}, following the monitoring Petals ESB sample),
# and add the following content:
{code}
# Define a service to check the queue size of an ActiveMQ queue used by the SE ASE
define service{
host_name petals-esb-node-1
service_description se-ase-queue-size
check_command check_munin!activemq_size!10!50
use generic-munin-service
}

# Define a service to check the traffic of an ActiveMQ queue used by the SE ASE
define service{
host_name petals-esb-node-1
service_description se-ase-queue-traffic
check_command check_munin!activemq_traffic!500!1000
use generic-munin-service
}
{code}

In our example:
- in nominal running, we should not have more than 10 pending messages. Over 50 pending messages, an error is thrown.
- and according to our volumetric estimations, we should not have more than 500 messages per 5 min. We accept up to twice our estimation: 1000 messages per 5 min.

Next, restart Naggios, start Petals and ActiveMQ. Go to the Nagios console:

On network domain configuration error, the message "{{I can't guess your domain, please add the domain manually}}" can appear on services associated to the queue size and queue traffic. So update:
- the command {{check_munin}} to force the domain name, example:
{code}
define command{
command_name check_munin
command_line /usr/lib/nagios/plugins/check_munin_rrd.pl -H localhost.localdomain -d localdomain -M $ARG1$ -w $ARG2$ -c $ARG3$
}

h4. Nagios screenshots

!nagios.jpg|align=center!


h4. Munin screenshots

h5. Queue size sample

!munin-activemq-queuesize.jpg|align=center!

h5. Traffic sample

!munin-activemq-traffic.jpg|align=center!

h4. Nagios screenshots