Sep 132018

A few months back now, I had the misfortune of overshooting my Internet quota, and winding up with a AU$380 bill for the month (and that was capped… in truth it was more like AU$3000).  In fact, it happened a couple of times until I finally nailed down the cause.

Part of it was NTP traffic (seems lots of cowboys write SNTP clients now and point them at, some was the Spambot Hunter Project and related activity.  In short, I invested some money into upping the quota, and some time into better monitoring.

I wanted to do the monitoring anyway to keep an eye on operations, as well as things like the solar panel voltages, etc.  Since I got it in place, I’ve been able to get much faster notifications of when things go awry.  Much sooner than the 120% quota usage alarm that Internode sends you.

I’m glad I did that now, last night I left a few tabs open on the site.  I noticed this evening they were still trying to load something and got suspicious… then I saw this:

Double checking, sure enough, something on one of those pages made Chromium get its knickers into a twist, and chew through all that data.

It took me a bit of tinkering to get the right query to extract the above chart.  Essentially there was a sustained 1.5MB/sec download for over 21 hours which would account for the 113.1GB that Internode recorded.

It’s a bit co-incidental that the usage dropped the moment I re-started Chromium.  Not sure why it was continually re-loading pages, but never mind.

The above data is collected using a combination of collectd and InfluxDB, with Grafana doing the dashboarding and alarms, and a small Perl script pulling the usage data off Internode’s API.

Aug 302018

I’ve succeeded in getting a working battery monitor kernel module. This is basically taking the application note by Technologic Systems and spinning that into a power supply class driver that reports the voltage via sysfs.

As it happens, the battery module in collectd does not see this as a “battery”, something I’ll look at later. For now the exec plug-in works well enough. This feeds through eventually to an InfluxDB database with Grafana sitting on top.