Issue with schedulling jobs after daylight saving weekend?

[thegunner157]

On daylight saving weekend which took place on 27.10.2024 after few hours from time change our scheduler stopped executing and scheduling new dag runs. We can see in logs that around 7.32 our pgbouncer broke due to too many open files which in effect our scheduler went down. We can also see that scheduler were trying to restart few time (around 15.30 and then around 18). I attach diagram of open and queued slots as well as number of running tasks.

Hence question, is it possible that time change may be the reason of pgbouncer too-many-open-files issue? If not what may be potential reason? On Sunday we have the least amount of dags scheduled hence workload cannot be an issue. Also resources of each of the components and connectivity were all fine.

We're using Airflow in version 2.7.1