Today, we had some issues with applications not being able to connect an Azure Database for PostgreSQL instance. The error was:

53300: remaining connection slots are reserved for non-replication superuser connections

I understand there are connection count limits (see: https://learn.microsoft.com/en-us/azure/postgresql/concepts-limits). However, how is an administrator expected to be able to perform problem diagnosis (ex: check for misbehaving applications) if they cannot login without access to the superuser attribute?

From https://learn.microsoft.com/en-us/azure/postgresql/concepts-servers#managing-your-server:

The PostgreSQL superuser attribute is assigned to the azure_superuser, which belongs to the managed service. You do not have access to this role.

  • You cannot; that is a limitation you have to live with on a hosted database. I would use a connection pool, that limits the number of connections. Nov 16, 2021 at 7:51
  • I wonder if AWS RDS has the same limitation? Docs (docs.aws.amazon.com/AmazonRDS/latest/UserGuide/…) imply that rds_superuser may be usable.
    – clucas
    Nov 16, 2021 at 13:22
  • It has the same limitations. All hosted databases do. Nov 16, 2021 at 14:38

1 Answer 1


Azure provides its own monitoring features for PostgreSQL. These might continue to work as they could presumably use those reserved slots to do the monitoring and present it to you. If you don't want to rely on 3rd parties to do our monitoring, you shouldn't rely on them to manage the database in the first place.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.