Check Command: check_internet_speed

Tests the speed of your Internet connection.

Demo Data

Out of the box, NEMS Linux 1.5+ will check the Internet connectivity speed using Cloudflare’s Speed Test service. By default, warning notifications will be generated if your upload or download speed falls below 10 Mb/s and Critical warnings if either falls below 7 Mb/s. These are just sample thresholds which can (and should) be modified to suit your connection speed by modifying the service in NEMS NConf.

Data Usage Warning

Every time the speedtest runs, anywhere from 100-400 MB of data is transferred (depending on your connection speed). Since the sample service is set to check every 30 minutes while in a good state, that could be nearly 5GB of data per day. If your Internet is slow, the sample service will check (retry) every 5 minutes, increasing the bandwidth usage significantly.

While in most cases this is fine, you must modify your thresholds to suit your connection, and modify your service schedule if you have limited or pay-per-use bandwidth.

Logging

A cache log is saved at /var/log/nems/speedtest.log whenever the script is run. In NEMS Linux 1.6+, this cache is used by NEMS TV Dashboard to display current Internet speed.

The format of this multi-line cache file is as follows:

State of service

Ping time

Ping measurement

Download speed

Download speed measurement

Upload speed

Upload speed measurement

Troubleshooting

Service check timed out after [number] seconds

If you are receiving a service check timeout and are certain you do indeed have Internet connectivity, the most likely culprit is that your NEMS Server is unable to process the speedtest within 120 seconds. A Raspberry Pi 4 with a reasonably fast MicroSD card should be able to perform a speedtest in under 40 seconds. Please upgrade your NEMS Server to an officially-supported platform. Power users may increase the value of service_check_timeout in /usr/local/nagios/etc/nagios.cfg however this may result in cascading checks, which will bring a low-powered SBC to its knees. You are much safer to upgrade to a board that meets your requirements.