memcached and Wikipedia app server - to - zero.wikimedia.org app server HTTP GET failures have been observed. This means that the Wikipedia Zero banners may not show and pages may not be rewritten, or they may be inaccurately presented.
Until the issue surfaces again, we will not be able to analyze this further.
flourine $ grep memcache /a/mw-log/zero.log
Not all items with !memcache in the log are necessarily hard failures due to the state machine aspect of memcached object clear and update, but use that command to identify entries and see the ZeroRatedMobileAccess extension for the specific places things are logged.
Version: unspecified
Severity: normal