@TheDJ reports frequent edit token errors on the web interface:
11:43 < thedj> ehm, guys, i'm getting a lot of session loss warnings when trying to save after preview... 11:47 < thedj> anomie: en.wp 13:27 < thedj> i can already see that both browser windows have the same enwiki session id, so i suspect there was no new session cookie 13:28 < thedj> tgr: centralauth tokens were also the same in both windows 13:33 < thedj> tgr: failed again. session cookies unchanged 13:33 < thedj> can't see if there is a header, since Safari filters that out in it's inspector view... <head> </desk> 13:41 < thedj> tgr: right. so it definetly seems that the api preview is causing it... 13:41 < thedj> if i have the problem and do save (error), save again, it works. 13:43 < thedj> but if I do save (error), preview, save again, then it seems to error again as well 13:45 < thedj> tgr: or not. 13:45 < thedj> no, it happens all the time. and it seems to be a lot worse now than it was before. 13:46 < thedj> oh wait, i also have livepreview on of course, so it actually previews 'all the time' if i have the edit window open. 13:47 < thedj> this also explains why no everyone is noticing it as bad as i am
(heavily edited)
Visible on graphite as well:
http://graphite.wikimedia.org/render/?width=586&height=308&_salt=1455047738.237&lineMode=connected&target=MediaWiki.edit.failures.session_loss.count
(big spike is T124440)
Timing matches 17:26 <elukey> mc1004.eqiad put back into redis/memcached pool from SAL.