Reading/Web/Notable incidents

This page is similar to the Release timeline but specifically to record trends/bugs in the site.

February
21st

a new deploy causes errors to spike to around 8K an hour (a little less than the spike on 15th).

20th

Around 2-4k errors as bugs related to caching ceased.

15th

An error spike on MinervaClientError's (12K an hour) up from the usual 3k. The problem seems to mostly effect US and Japanese users on en.wiki and jp.wiki. 1395 errors occurred on a single page in an hour period on Android Chrome Mobile but I couldn't replicate any issues even with the page and browser version available. Finally, I managed to replicate the problem: caching. Explanation here: https://phabricator.wikimedia.org/T208915#4958060

January
23rd

A patch was deployed Explicitly pass in parseHTML with the hope of dealing with many of the issues that appeared on 17th.

15th-17th

Grafana is missing some events (most notably ReadingDepth, VirtualPageViews), although they were recorded correctly in the EL databases.

This was due to a PDU issue that affected

17th

MinervaClientError jumps again from 30 to 120k 2019-01-17 at 18:00:00 UTC(?). Not seeing anything obvious in https://wikitech.wikimedia.org/wiki/Server_Admin_Log or Deployment calendar. Stephen saw a problematic banner so this might also be related. 35% of errors come from iOS and 74% of traffic is on enwiki. The Steward nominations banner does appear to be throwing an error and when looking at referrer traffic for client side errors, the pages impacted do seem to coincide with places the banner is running. This was tracked and fixed but bugs were still at normal levels with the majority coming from iOS. Some of these bugs may be related to the page issues deploy so we are looking more closely...

9th

MinervaClient errors jump from 4k a minute to 40k a minute with the 1.33.0-wmf.12 deploy. Owch. It turned about to be due to QuickSurveys being disabled on English WIkipedia but some surveys still being active in cached HTML. We promptly pushed it back to normal levels.

December
20th

Bug fix deployed: T211986

November
5th

[MobileFrontend refactor bug]

Bug T208605 was squashed. Minerva.WebClientError returns to baseline.

October
19th

[MobileFrontend refactor bug]

A suspected iOS Safari bug caused a huge error spike in number of errors in Minerva.WebClientError. (~30k to ~120k) Error in MediaWiki_1.33/wmf.1 (T208605).