Thanks Guilaume, is this the same accident which caused an hour delay of Wikidata items on Wikipedia watchlists?
Cheers Yaroslav On Thu, Oct 19, 2017 at 10:14 AM, Guillaume Lederrey < gleder...@wikimedia.org> wrote: > Hello all! > > As you might have seen / endured, we've had a Wikdiata Query Service > partial outage yesterday morning (central european time). The full > incident report is available [1] if you are interested in the details. > The short version: > > * a single client started to run an unusually high number of queries on > WDQS > * the overload was not prevented by our current throttling > * the failure was not detected and isolated automatically > > To prevent this from happening again, we will review our throttling > rules. Those rules were previously tuned to prevent a single client > from overloading the service with a small number of expensive > requests: we started to log a client activity only when the duration > of a request exceeded 10 seconds. Which means that a client sending > tons of short requests would never be throttled. > > We will correct that by lowering the threshold to probably 25ms. The > throttling rules are still the same: > > * 60 seconds of processing time per minute (peaking at 120 seconds) > * 30 errors per minute (peaking at 60) > > If you are using WDQS to make lots of small requests, and you are over > the throttling rates above, there is a chance that you will start > seeing throttling errors. We are not doing this to bother you, we're > just trying to keep another crash from happening... > > If you are throttled, you will receive an HTTP 429 error code. This > response include the "Retry-After" HTTP header which specify a number > of seconds you should wait before retrying. > > Thanks for your patience! > > And contact me if you want any clarification. > > Guillaume > > [1] https://wikitech.wikimedia.org/wiki/Incident_ > documentation/20171018-wdqs > [2] https://en.wikipedia.org/wiki/List_of_HTTP_status_codes#429 > > -- > Guillaume Lederrey > Operations Engineer, Discovery > Wikimedia Foundation > UTC+2 / CEST > > _______________________________________________ > Wikidata mailing list > Wikidata@lists.wikimedia.org > https://lists.wikimedia.org/mailman/listinfo/wikidata >
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