Starting to use Memcached and found some of the current Memcached bits in Observium not working optimally. I wrote a new unix-agent script using python rather than PHP. The previous script relied on PECL memcached but didn't do anything for installations using PECL memcache. After a bunch of trial and error I determined that it was easiest to write the script in Python which requires the python-memcached library and is readily available on different OS types and versions.
I also modified the applications/memcached.inc.php and polling/unix-agent.inc.php to accommodate the new script. They will also accurately separate different instances of memcached running on the same server as reported by the script.
I'm still trying to work out a couple things. The main thing is when you enable Memcached as an application for a device Observium automatically creates an entry in the database but the instance is NULL. When the unix-agent reports on the Memcached instance(s) running on the server new entries get created in the database for each instance and the app with the NULL app_instance never gets used. I've been manually removing it from the database. If possible I would like to work it out so that it doesn't get created automatically. If that's not possible I was going to look into updating that entry with the first real instance reported by the agent.
Also wanting to get the Apps tab for the Device to better identify each instance and maybe work on some additional metrics reporting for Memcached specific stats.
Patch attached, let me know if it is acceptable or not...
Britt Treece