== YK-VAL Munin Plugin

Munin is a powerful system monitoring solution.  See
http://munin-monitoring.org/ for more information.  This document
documents how to install and enable the YK-VAL Munin plugins on a
Munin node.  You need to install and configure Munin before following
these steps.

The following Munin plugins are shipped as part of YK-VAL.  They make
it easy for you to monitor your YK-VAL installation.

ykval_ksmlatency::
 Monitor the latency to each KSM.  A useful side effect is that it tests 
 whether the KSM is operational for the particular validation server.

ykval_vallatency::
 Monitor the latency to the other VAL servers, for
 both IPv4 and IPv6.

ykval_queuelength::
 Monitor the size of the YK-VAL queue.

The plugins are installed by 'make install' but needs to be configured
before they can be used.  First create a Munin configuration file to
make sure the plugins can access the YK-VAL ykval-config.php
configuration file:

[source, sh]
----
user@val:~$ sudo sh -c 'cat > /etc/munin/plugin-conf.d/ykval'
[ykval_ksmlatency]
group www-data
[ykval_vallatency]
group www-data
[ykval_queuelength]
group www-data
user@val:~$
----

Then check that they are working properly:

[source, sh]
----
user@val:~$ sudo /usr/sbin/munin-run --servicedir /usr/share/munin/plugins ykval_queuelength autoconf
yes
user@val:~$ sudo /usr/sbin/munin-run --servicedir /usr/share/munin/plugins ykval_queuelength config
graph_title YK-VAL queue size
graph_vlabel sync requests in queue
graph_category ykval
queuelength.label sync requests
queuelength.draw AREA
user@val:~$ sudo /usr/sbin/munin-run --servicedir /usr/share/munin/plugins ykval_queuelength 
queuelength.value 0
user@val:~$
----

Enable the plugin as follows:

[source, sh]
----
user@val:~$ sudo munin-node-configure --shell | sudo sh
user@val:~$ sudo /etc/init.d/munin-node restart
Stopping Munin-Node: done.
Starting Munin-Node: done.
user@val:~$ 
----

After some time, you should see new graphs on your Munin master.