Description

In Dec 2021 we disabled Dovecot's stats writer service for DMS v10.4.0.

• Reasoning was to avoid logging an error that wasn't causing in particular problems but was assumed to be caused by a misconfiguration (or lack of configuration to have the service enabled by default). There was no clear reproduction given to trigger it however.
• There was discussion about Dovecot potentially fixing it with the release that came in DMS 10.4.0 (which also upgraded to Debian 11 base image), but this was not investigated since the "fix" was part of this release too.

Presumably reverting the "fix" will not bring back the error log, but if it does it should be better understood with a valid reproduction. Documentation about this change to our Dovecot configuration and the impact on users interested in Dovecot's stats service was never added to our docs.

Actionable: Restore the stats-writer service (that's otherwise enabled by default upstream) and does work.

References

Most recent investigation + context: #4385 (comment)

Users wanting metrics to work but having trouble following upstream docs due to our modifications:

• Disable service stats for Dovecot explicitly #2292 (comment)
• bug report: configured dovecot stats/metrics are always 0 #4164
• [Bug]: doveadm stats dump doesn't display updated statistics #4385

#2292 (comment)

I'd still rather understand why it's being triggered tbh rather than hiding a warning. If it is something Dovecot is doing by default when an IMAP login or similar metric occurs, it'd make more sense to either disable statistics by default explicitly or properly setup and document them.

#2292 (comment)

It also looks like the issue may have been related to an earlier release of Dovecot we had, and if that no longer needs the workaround, then it could be dropped. It didn't seem like it was clear what was causing the error to reproduce it unfortunately