Hi Wikitech Ambassadors,
I am a new hire of the Wikimedia Analytics team, it's nice to reach out to you all for the first time!
I have to start with an apology since I missed to inform you about a rather intrusive maintenance work to the servers the user sessions. I needed to install the Debian Jessie OS on those servers, replacing Ubuntu Precise, as part of one big infrastructure goal that we have. If you have experienced issues with your session for brief amount of time during the past three days (like 30 minutes at the time) it was probably due to me removing servers from the available pool to work on them. I followed the least impactful procedure but sadly I couldn't have avoided session loss.
Everything is tracked in https://phabricator.wikimedia.org/T123711 for the curious. I am planning to finish the bulk of the work tomorrow during EU time, please feel free to reach out to me (elukey on IRC/Freenode) for any question or to report any issue.
Thanks!
Luca