Hi everybody,

The upgrade day has been scheduled, we are going to migrate Hadoop to the Apache Bigtop distribution on February 9th, during the EU morning. This will require from 2 to 4 hours of Hadoop downtime, since the upgrade will be very delicate and complex.

I created https://phabricator.wikimedia.org/T273711 to track more precisely timings and updates, please use it to ask questions and to tell us if this impacts your work or important deadlines for your team (in case we'll try to find a different time window).

Since we are upgrading software that was released years ago, it may probably happen that right after the upgrade some tools/workflows/etc.. don't work as expected anymore. We have tested a wide variety of use cases in our testing environment, but some corner cases might have been missed. In case you notice something weird right after the upgrade, please let us know how to repro in the task, we'll follow up and hopefully fix promptly.

Thanks a lot for the support!

Luca