We have a single harbor instance at work, backed by PG. The folks ran into some sort of performance issue during their testing (not documented) and their solution was to use cloud native pg, run two postgres, and add additional second layer of connection pooling.

We eventually hit a bug in a combination of certain images, docker desktop (not even supported by us), and permissions. The error looked related to the connections, so I suggested the pooler be bypassed as a test. They ignored the suggestion for two weeks until it was the last thing to test.

Sure enough bypassing the pooler helped stabilize the connection from harbor during image uploads.

Now I need to talk to them about properly vertical scaling PG before we try and run two with replication, in the same kube cluster, in the same physical data center.