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From: "Squiry (@Squiry)" <noreply+Squiry@github.com>
To: "pgjdbc/pgjdbc" <noreply+pgjdbc-pgjdbc@github.com>
Date: Tue, 28 Nov 2023 16:41:40 +0000
Subject: Re: [pgjdbc/pgjdbc] PR #3012: Support multiple hosts defined with single hostname
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(on pgjdbc/src/main/java/org/postgresql/hostchooser/HostChooserFactory.java:45)

So, [libpq](https://github.com/postgres/postgres/blob/master/src/interfaces/libpq/fe-connect.c#L3967) looks at provided hosts as a single backend per host: if it connects to any address of provided host and finds out it is not in a desired state it rejects the host and doesn't even bother try next addresses.

Golangs [pgx](https://github.com/jackc/pgx/blob/master/pgconn/pgconn.go#L147) treats every address as a separate instance and tries them all, only stops on auth errors. That behavior would be more preferred for me as I have case for single hostname backed with addresses for every db instance.

Error propagation becomes more interesting anyway, because connecting to something like localhost will throw some interesting exceptions like `Could not find a server with specified targetServerType: any` instead of auth errors, but it can be fixed.