The following bug has been logged on the website:
Bug reference: 17974
Logged by: Michael Guissine
Email address: mguissine@gmail.com
PostgreSQL version: 14.8
Operating system: AWS RDS
Description:
We are running relatively large and busy Postgres database on RDS and using
logical replication extensively. We currently have 7 walsenders and while we
often see replication falls behind due to high transactional volume, we've
never experienced memory issues in 14.6 and below. After recent upgrade to
14.8, we already had several incidents where walsender processes RES memory
would suddenly increase to over 80GB each causing freeable memory on the
instance to go down to zero. Interesting that even after Instance reboot,
the memory used by walsender processes won't get released until we restart
the replication and drop the logical slots. The logical_decoding_work_mem
was set to 512MB in time of the last incident but we recently lowered it to
128MB.
Any known issues in pg 14.8 that would trigger this behaviour?
