ClonePanel

Apparently I need a backup for my backup vps, which is currently unreachable. I know it’s still running because I’m still getting e-mail from it through gmail - messages indicating that it’s unable to connect to any of the other servers! And this is what you’re seeing on the monitor display - the grey means no data, and clearly the monitor script needs improvement because really it should show all grey for the past hour or so.

Meanwhile, to get some real monitor results, I’ve started up the old linux machine on my own dsl connection. It’s a good idea every week or two anyway since it will sync all the accounts and give me another off-site backup - one that’s easily copied to DVD.

Potentially a problem though is that I now have two systems both trying to write the monitor data to a single host. I need some elegant way to deal with this…

Update: The VPS is now back online and all is normal. To avoid the monitor data issue I changed the value of MONITOR_RESULT_DIR on the second machine. The final step to redundancy is to use a redirect on the monitor server which would send the backup data if the main data is unavailable.

A quick demo of the monitor display. This is live data for real servers (names have been changed to protect the innocent!).

Update - 01 November 2006

Added a javascript style-switcher and summary information (this month’s percentage availability and number of days uptime).

Notes

Measurements are taken at 5 minute intervals, represented here by one pixel - a total of 12 hours range on the graphs shown. Javascript keeps the graphs updated (reloading the latest data file every 5 minutes) as long as you stay on the page.

Initial view is server load average. Use the “LTMFSD” buttons or the style changer in your browser (eg. View -> Page Style) for other parameters: page load time, free memory, swap memory, MySQL connection and disk space.

The coloured display is indicative only, based on roughly a log scale, so that small variations are visible. For example on the load average display there is a visible difference between a load of 0 and 0.2, yet the full scale covers up to 100.

To view actual measurements click anywhere on the graph (you need to be quite precise).

Normally the monitor would be inserted into any page just by adding the stylesheet links in the head and a javascript tag in the body. In this case I’ve used an iframe to avoid permission problems in Firefox and other Mozilla-based browsers. (The javascript loads data files from another domain).