PgCat should not return and log 'all servers down' when failing to obtain a connection from the pool #824
Description
This is related to #822 - we were seeing this message when trialling PgCat in our production environment. We couldn't see why the Postgres server in question was down, and the answer is that it wasn't 🙂
Instead, we were queueing for longer than connect_timeout. When that happens in PgBouncer, you get this:
linear_production_copy=# SELECT 1;
FATAL: 08P01: query_wait_timeout
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
In PgCat, you get this:
linear_production_copy=# SELECT 1;
FATAL: 58000: could not get connection from the pool - AllServersDown
Which is partly right and partly misleading. I think PgCat should use a more specific error message in this case. I'm happy to create a PR if people agree.