[EventService] An singleton event (ScheduledNotificationDispatchEvent) was received but another singleton event of the same type is already in progress. Skipping.

[Yaytay]

We see this log message every minute:

[EventService] An singleton event (ScheduledNotificationDispatchEvent) was received but another singleton event of the same type is already in progress. Skipping.

How worried should we be?
Is something taking a lot longer than it should?

Running dependencytrack/apiserver:4.13.6 in Docker Swarm on prem, with PostgreSQL running in AWS.

Thanks.

[nscuro]

That event fires every minute. It is defined as singleton to prevent duplicate execution which could lead to data races. If you see this warning it means that processing a single event takes longer than 1min. This could hint at bad performance when assembling scheduled notifications, but is otherwise nothing to worry about. What / how many scheduled notifications have you configured?

[Yaytay]

If Notifications is the same as Alerts, I have none setup.

[nscuro]

Then it could be that event processing in your instance has a large backlog, and enqueued events are not processed within 1min. This would indeed be worrying.

Do you have many projects and / or large volumes of BOM uploads in your instance?

[Yaytay]

We have 621 projects, but 26,000 BOMs.
New BOMs are uploaded hourly, and I have a script that purges old projects, but it does not explicitly purge old BOMs.

[nscuro]

Are you uploading the BOMs in large batches? That could explain the backlog, since:

• Processing of BOM uploads
• Vulnerability analysis
• Policy evaluation
• Metrics updates
• Component metadata (e.g. latest version) fetching

are all separate tasks that contribute to the backlog.

If this is the case and the system otherwise behaves as expected, the warning log about ScheduledNotificationDispatchEvent is not problematic. Especially if you don't use the backing feature.

[Yaytay]

At least five BOMs are uploaded every hour, but usually 10ish per hour, the upper bound is around 200, but that would imply that every service we have has been updated that hour and I wish we kept our stuff that up to date.

The system is currently taking a very long time to process BOMs.