LISTEN/NOTIFY on AWS Aurora/postgres

Question

I am hoping to implement a trigger that fires a notify on table change in PostgreSQL, but I am unable to find any definite answer to if it would work in a cluster.

Does PostgreSQL listen/notify work on AWS Aurora (both provisioned and serverless), and can I expect all clients to receive notifications regardless of what instance they are connected to?

If yes, are there any major performance concerns?

Thanks :)

Clearcole

It should be quite simple to spin one up and test. Someone might have already tried. – Andrej

I don't see any performance penality with aurora postgres 13.6 (serverless 2) – Moreno

Answer 1

The best AWS Documentation implies - YES, it does work

Specifically for Aurora Serverless, there is an advisory that "LISTEN/NOTIFY" is NOT RECOMMENDED. This implies that it's possible with Aurora Serverless but not advisable. It also implies that normal RDS LISTEN/NOTIFY does work and is ok to use.

https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/aurora-serverless.html

Currently, certain SQL queries and commands, such as cursors with hold (DECLARE name ... CURSOR WITH HOLD FOR query); session-level advisory locks; temporary relations; and asynchronous notifications (LISTEN, NOTIFY commands) prevent scaling and are not recommended

My own quick test on AWS shows - Yes, it does work

1. Launch Instance with Public Access

...

2. Allow Traffic

3. Run command in dbeaver

Note: This test doesn't show a successful receipt of a notification. That will need a quick console application to test that.

Andrej

Note that they removed that the doc reference is for serverless 1. For serverless 2 they removed the advice : docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/… – Moreno

I also have tested it on serverless 2 with postgres 13.6 – Moreno