May 2008 Archives

Stephen Dolan, a student at Trinity College Dublin, has written an article about internal link connectedness in Wikipedia. It’s worth a read anyway, but I was particularly tickled by a throwaway link he includes at the end.

Stephen’s software needs to run a quadratic-time algorithm on the two million or so Wikipedia entries, so he uses lots of servers in parallel to crank through all the work. And he includes a graph of CPU temperature on one of the servers he’s using. It’s pretty clear which 4-day period his job was running on…

If you have any other interesting examples of system-monitoring output, let us know in the comments, or drop us an email on sysmonblog@googlemail.com.

There is a tendency sometimes to think that system monitoring tools like munin, zenoss, zabbix or nagios are mainly for the sysadmin. We think the people who can benefit from monitoring is considerably bigger.

How to setup a 2-way alerting service over sms/text/pager, in this instance, for Nagios.

We’re really hoping that Part two and three do indeed follow in a timely fashion and deliver the goods, because part one certainly whets the appetite. (Update: Part two and Part three are up)

Good quality alerting is really useful and important, but there are so many issues to deal with:

Chris Josephes makes an excellent point about disk usage alerts:

[T]he monitoring system should compare the standard deviation for the file-system percentage over the past 24 hours, and compare it to the standard deviation for the past hour.

It isn’t (just) about what percentage of the file-system is full/free, but how fast it’s filling up. A disk that has sat at 20% full for a year, then creeps up to 50% full in 24 hours …. is that something worth pointing out?

So what else, aside disk, might you want more intelligent monitoring on?

We’re interested in system monitoring, graphing, reporting, alerts and tuning. How to make the daily life of your typical sysadmin a little easier.

This is our little collection of notes, ideas, thoughts and links on the web.

You can reach us at sysmonblog@googlemail.com

Patches, ideas, feedback all welcome.