[discovery] WDQS timeout and slowdown - Incident report

Hello! As you might already know, Wikdiata Query Service has been misbehaving in the last 24 hours. Our public SPARQL endpoint [1] was slow and throwing timeouts. Sadly, exposing a public SPARQL endpoint is a hard problem and we don't have a final solution to this. Still we have some improvements. Have a look at the incident report [2] if you want details. I also started to write a runbook for WDQS [3]. This should be interesting mostly to our SRE team, but feel free to also have a look and suggest improvements / clarifications. Note that our internal WDQS endpoint was stable during that time (as expected). Thanks for your help and your patience! Guillaume [1] https://query.wikidata.org/ [2] https://wikitech.wikimedia.org/wiki/Incident_documentation/20180625-wdqs [3] https://wikitech.wikimedia.org/wiki/Wikidata_query_service/Runbook -- Guillaume Lederrey Operations Engineer, Search Platform Wikimedia Foundation UTC+2 / CEST