We will upgrade our Gerrit to [version 3.3]. We have scheduled it on Tuesday, August 3rd at 16:00 UTC. We will first upgrade the [Gerrit replica] then the primary server. The service will thus be unavailable for a few minutes while we conduct the operation and restart the service.
The July 19th upgrade took a bit longer than expected since we were trying our runbook for the first time. We have since improved our documentation and addressed a few configuration glitches we had.
This upgrade comes with a new feature: "Attention Set". It replaces change assignees with a list of people that are expected to act on the change. It helps better differentiate changes you have already reviewed from the one you have to review or amend. The feature is nicely explained on upstream documentation page: http://gerrit-documentation.storage.googleapis.com/Documentation/3.3.1/user-attention-set.html