Munin graphs not updating
uptime is a Linux command that has varied output between systems but will report on how long the server had been running, how many users are logged in and what the load average of the server is.
Here is an example output from my local machine (which was doing a lot of code updates and database processing on a development site at the time).
The default Munin configuration options are usually fine, unless you need to alter the directories Munin uses to write out the graphs.
For example, if you changed the Apache webroot then you will need to alter the config option to point to the same place.
This is because internally the request appears to be coming from the internal network.
This data is not the sort of thing you want everyone to see!
With the output of this command in a property I then used some other processing to extract the data needed and add this to a log file, which was updated thanks to a cron task that just ran the Phing file every 2 minutes.
With this log file I created a web page that then graphed the output using Flot charts.
By default this will only allow access from the localhost IP address and so you might want to add a couple of Allow rules.
After installing Munin server on a few different systems as a test I have found that some systems (e.g.
Ubuntu) will set everything up, whilst others tend to leave the finer detail to the administrators.
The system is modular so it can be extended to include Apache load, Varnish statistics, My SQL load, and even the number of emails sent.
After using Munin for a couple of weeks I am really impressed by how much data I can view, and it has even allowed me to track down a performance issue on a server.
This is the primary hub of the Munin reporting tool and where you can view the data from each of your Munin nodes.