Everything is a Freaking DNS problem

During my Puppetcamp Gent talk last week, I explained how to get alerts based on trends from graphite. A number of people asked ,e how to do that.

First lets quickly explain why you might want to do that .
Sometimes you don't care about the current value of a metric..as an example take a Queing system .. there is no problem if there are messages added to the queue, not even if there are a lot of messages on the queue, there might however be a problem if over a certain period the number of messages on a queue stays to high.

In this example I`m monitoring the queue length of a hornetq setup which is exposed by JMX.
On the server runnnig HornetQ I have an exported resource that tells the JMXTrans server to send the MessageCount to graphite
(you could also do this using collectd plugins)

@@jmxtrans::graphite {"MessageCountMonitor-${::fqdn}":
    jmxhost => hiera('hornetqserver'),
            jmxport => "5446",
            objtype => 'org.hornetq:type=Queue,*',
            attributes =>  '"MessageCount","MessagesAdded","ConsrCount"',
            resultalias => "hornetq",
            typenames => "name",
            graphitehost => hiera('graphite'),
            graphiteport => "2003",
}

This gives me a computable url on which I can get the graphite view

The next step then is to configure a nagios check that verifies this data. For that I need to use the check_graphite plugin from Datacratic ..

Which can work with an nrpe config like

### File managed with puppet ###
### Served by:        '<%= scope.lookupvar('::servername') %>'
### Module:           '<%= scope.to_hash['module_name'] %>'
### Template source:  '<%= template_source %>'
 
command[check_hornetq]=/usr/lib64/nagios/plugins/check_graphite -u "http://<%= graphitehost%>/render?target=servers.<%= scope.lookupvar('::fqdn').gsub(/\./,'_')%>_5446.hornetq.docstore_private_trigger_notification.MessageCount&from=-30minutes&rawData=true" -w 2000 -c 20000

I define this check on the host where HornetQ is running as it then will map to that host on Icinga/Nagios rather than throw a host error on an unrelated host.

If you are hacking on monitoring solutions, and want to talk to your peers solving the problem
Block the monday and tuesday after fosdem in your calendar !

That's right on february 6 and 7 a bunch of people interrested to fix the problem will be meeting , discussing and hacking stuff together in Antwerp

In short a #monitoringsucks hackathon

Inuits is opening up their offices for everybody who wants to join the effort Please let us (@KrisBuytaert and @patrickdebois) know if you want to join us in Antwerp

Obviously if you can't make it to Antwerp you can join the effort on ##monitoringsucks on Freenode or on Twitter.

The location will be Duboistraat 50 , Antwerp
It is about 10 minutes walk from the Antwerp Central Trainstation
Depending on Traffic Antwerp is about half an hour north of Brussels and there are hotels at walking distance from the venue.

Plenty of parking space is available on the other side of the Park

I found the initial announcement in my Spambox, thats where I send all the mails from GroundWork as unsubscribing from their marketing lists doesn't seem to work ..

Tarus pointed it out.. he already mentionned Marketing, low community imput etc..

Nevertheles I had a look, and my first and last impression was, NagiosForge, no active community, and empty pages on other imvho more relevant Monitoring Projects created by GroundWork employees.

Big John coined the "to pull a GroundWork" phrase aiming at their early products, err logo placements. When we were evaluating differen Open Source monitoring tools for our OLS paper about 18 months ago we looked at the tool and it didn't make the cut .. it failed in all areas where it claimed to be strong, ease of installation , lack of errorhandling during the installation, etc ... some while later another collegue tried again and we ran into similar problems

Yet some people claim it to be a great product.. I'm not a fan yet ...maybe one day they they'll know to convince me .. but for now
When I need Nagios .. I`ll be looking at Djagios , Opsview , Icinga or the real thing.

However, ther's still Hyperic, Zenoss and Zabbix :)