PostgresChannelMessageTableSubscriber not properly handling Database Failover

[joshiste]

In what version(s) of Spring Integration are you seeing this issue?

6.x

Describe the bug

When the database is doing a failover the PostgresChannelMessageTableSubscriber doesn't notice and will never receive new notifications.
For example on AWS RDS instance with multi-AZ standby, when performing a failover the IP address for the DNS does change. But PostgresChannelMessageTableSubscriber never re-establishes a connection, nor has some other measurement in place to validate that the connection is still valid.

To Reproduce

Perform a DB failover. After this no more messages will be processed.

Expected behavior

Eventually the PostgresChannelMessageTableSubscriber obtains a new connection after failover, and message processing will work again.

Sample

Sorry, not being able to provide a complete sample, as this involves infrastructure 🤷‍♂️

[joshiste]

I'd also be happy to contribute a PR for this.

I would propose to use a configurable timeout for retrieving PGNotifications instead of waiting forever and when the received list is empty to re-new the connection

[joshiste]

P.S. I also think it's a pity that the PostgresChannelMessageTableSubscriber is a final class. If it either would be an interface or non-final, It would be a lot easier for users to get rid of the faulty behavior...

[artembilan]

Thank you for looking into this!
I'm not sure how would an interface for the PostgresChannelMessageTableSubscriber help since this class has a lot of specific logic.

Will look into your PR shortly.