RIPE Atlas
The RIPE Atlas is a distributed network monitoring project to measure reachability and latency. There are two device types, Probes and Anchors. Probes are small, USB-powered appliances, while Anchors are 1U rack mounted equipment. Probes and Anchors test connectivity to remote Anchors and DNS root servers, and report their results to the Atlas website. WMF hosts five Anchors, one in each of our datacenters.
The Atlas has been used to measure things like AAAA filtering, DNS root server reachability, and Internet routing response to hurricanes: https://atlas.ripe.net/results/analyses/
In addition to the stats you can get from RIPE's site, we track some statistics of our own: https://grafana.wikimedia.org/d/K1qm1j-Wz/ripe-atlas?orgId=1
Run tests from the command line
Atlas has a suite of command line tools to interact with its API. On "cluster management" production hosts (cumin1001.eqiad.wmnet, cumin2002.codfw.wmnet) SRE has the tools installed and they can be accessed when running as the 'atlas' user. All tools are also aliased with the correct sudo invocation for convenience, for example running a ssl certificate test from 99 italian probes:
cumin1001:~$ source /etc/ripeatlas.alias # load sudo aliases
cumin1001:~$ asslcert --target text-lb.esams.wikimedia.org --from-country it --probes 99 --no-report
Looking good! Your measurement was created and details about it can be found here:
https://atlas.ripe.net/measurements/22900971/
cumin1001:~$
Country latency measurement
latency-measurement can be used to automate the measurement of latency of each country to the various WMF servers.