Hi all,
I have a use case for which I am considering using Postgres Logical Replication, but I would like to scale up to 100 or even 200 replication slots.
I have increased max_wal_senders and max_replication_slots to 100 (also making sure that max_connections is large enough). Things seem to be working pretty well so far based on some PoC code I have written. Postgres is creating a walsender process for each replication slot, as expected, and the memory footprint of each one is around 4MB.
So I am quite happy with the way things are working, but I am a bit uneasy about increasing these configuration values by 10-20x compared to their defaults (both max_wal_senders and max_replication_slots default to 10).
Is there anything I should be looking out for specifically? Is it considered an anti-pattern to use that many replication slots and walsender processes? And, when my database comes under heavy write load, will walsender processes start consuming a large amount of CPU / memory (I recognize that this is a vague question, I am still working on some empirical testing).
Finally, I am currently using Postgres 14. Should I consider upgrading to Postgres 15 or 16 based on my use case?
Thanks in advance for any insight on this.
Antonin
