Re: postgres disconnects on master after setting up replication

Andy Hall <andyjohnhall@gmail.com> writes:
> we have an odd issue where a java app using JDBC which has been
> working fine has suddenly started disconnecting after we setup
> replication from the database it was connecting to ( which is now the
> primary in a replicating pair ) with errors such as the following...

> CLIENT SIDE: DBNAME/logs/20210815-200601.20966.log:SessionManagerImpl
> WARN 20210816-00:01:00.252 - A session lost connection with the
> database. Disabling all sessions
> SERVER SIDE: 2021-08-16 01:48:27 BST FATAL: unsupported frontend
> protocol 1234.5680: server supports 1.0 to 3.0

Hmm.  That "protocol version" is a GSS request:

#define NEGOTIATE_GSS_CODE PG_PROTOCOL(1234,5680)

So

1. You are using a server version that predates our GSS support.

2. On the other hand, the client knows GSS and is trying to use it.
The client should fall back to a non-GSS connection upon receiving
this error response.  But ...

3. Something --- it's not very clear what --- is seeing the error
and going into an unwarranted panic.

I'd try to figure out what's issuing the "Disabling all sessions"
message and then filing a complaint with the authors of that.

            regards, tom lane