Something appears to be wrong with how the MobileWikiAppSessions schema measures sessions on dewiki - and it changed drastically with the rollout of 2.1.141 on February 15:
There are some options for attempting to isolate the cause further by examining this along some other dimensions (e.g. perhaps it's certain click sources, counted in the schema's "from" fields, that behave differently on dewiki). But hopefully someone from the team already has an idea what's going on here.
Data sources (all queries measuring production releases only, i.e. leaving out beta versions):
SELECT YEARWEEK(LEFT(timestamp, 8)) AS yearweek, AVG(event_totalPages) AS avgtotalPages FROM log.MobileWikiAppSessions_14031591 WHERE userAgent LIKE '%-r-%' AND wiki = 'dewiki' GROUP BY yearweek ORDER BY yearweek; SELECT YEARWEEK(LEFT(timestamp, 8)) AS yearweek, AVG(event_totalPages) AS avgtotalPages FROM log.MobileWikiAppSessions_14031591 WHERE userAgent LIKE '%-r-%' AND wiki <> 'dewiki' GROUP BY yearweek ORDER BY yearweek; SELECT LEFT(timestamp, 8) AS date, COUNT(*) AS sessions, MID(LEFT(userAgent,INSTR(userAgent,' ')-1),INSTR(userAgent,'/')+1) AS app_version FROM log.MobileWikiAppSessions_14031591 WHERE userAgent LIKE '%-r-%' GROUP BY date, app_version ORDER BY date, app_version SELECT LEFT(timestamp, 8) AS date, COUNT(*) AS sessions, MID(LEFT(userAgent,INSTR(userAgent,' ')-1),INSTR(userAgent,'/')+1) AS app_version FROM log.MobileWikiAppSessions_14031591 WHERE userAgent LIKE '%-r-%' AND wiki = 'dewiki' GROUP BY date, app_version ORDER BY date, app_version SELECT LEFT(timestamp, 6) AS yearmonth, COUNT(*)/COUNT(DISTINCT event_appInstallID) AS sessionsperuser FROM log.MobileWikiAppSessions_14031591 WHERE userAgent LIKE '%-r-%' GROUP BY yearmonth ORDER BY yearmonth
See also Spreadsheet
