Debian Stretch's security support ends in mid 2022, and the Foundation's OS policy already discourages use of existing Stretch machines. That means that it's time for all project admins to start rebuilding your VMs with Bullseye (or, if you must, Buster.)
Any created in the last year or two are most likely using Buster images already, so there's no action needed for those. Older kubernetes jobs should be refreshed to use more modern images whenever possible.
If you are still using the grid engine for webservices, we strongly encourage you to migrate your jobs to Kubernetes. For other grid uses, watch this space for future announcements about grid engine migration; we don't yet have a solution prepared for that.
Details about the what and why for this process can be found here:
https://wikitech.wikimedia.org/wiki/News/Stretch_deprecation
Here is the deprecation timeline:
March 2021: Stretch VM creation disabled in most projects
July 6, 2021: Active support of Stretch ends, Stretch moves into LTS
<- You are Here ->
January 1st, 2022: Stretch VM creation disabled in all projects, deprecation nagging begins in earnest. Stretch alternatives will be available for tool migration in Toolforge
May 1, 2022: All active Stretch VMs will be shut down (but not deleted) by WMCS admins. This includes Toolforge grid exec nodes.
June 30, 2022: LTS support for Debian Stretch ends, all Stretch VMs will be deleted by WMCS admins