That is strange, because while "enwiki.analytics.db.svc.eqiad.wmflabs" is "new" because it is served by new sets of servers and has been upgraded recently, plus it is being tuned; toolsdb has not been touched I think for a couple a weeks, when it was upgraded, plus at the time it is not handled by a proxy. Do you use connection pooling/persistent connections? That is not allowed [2], but more important than that, it may create connection problems if a server fails over automatically, because it will keep pointing to the wrong server. There was not an overload on toolsdb last week that could explain the extra writing load: [0]. There was one overload, however, on labsdb1009 (analytics) during the weekend, which lead to me baning/throttling and notifying several users as they had created a denial of service: [1] Notice one big change on the new servers (analytics and web) is that right now there is no query limitation- if some user runs 10 long-running queries, they can and that could affect other users, I have not limited that except on per user issues- if the community wants to agree and set up some, I can do that with no problem, but now that we are not so resource-bound I did not want to introduce artificial limitations as some people didn't like the limits on the old servers because of lower resources. [0] < https://grafana.wikimedia.org/dashboard/file/server-board.json?refresh=1m&a… [1] <https://phabricator.wikimedia.org/T182997[2] < https://wikitech.wikimedia.org/wiki/Help:Toolforge/Database#Connection_hand… This sounds like something that is worth of opening a Phabricator task > about. We do have an existing ticket > (<https://phabricator.wikimedia.org/T180380>) that may also be somehow > related depending on where the disconnects are happening. Please share details of connection (user, code, timestamps) on a phabricator task- maybe there is a slowdown on toolsdb we have not yet realized. That way we can have a deeper look. -- Jaime Crespo <http://wikimedia.org