Re: Lightest way of checking if postgresql is running at the other end of an ssh tunnel?

On Wed, May 11, 2016 at 11:17:54AM +0200, Niels Kristian Schjødt wrote:

> We have an ssh connection running from one server to our
> postgresql database on another server. Some times we
> experience that the ssh tunnel does not work anymore and
> needs to be restarted, even though we use the autossh
> package. I would like to write a script that “pings”
> postgresql on the specified port, to check if the connection
> goes through. I have tried with netcat, but it does not
> really check if postgresql is in the other end of the tunnel,
> it only check if there is as service (the tunnel) listing on
> the port on the local machine. Is there another way of
> pinging the port, to see if postgresql is alive at the other
> end? If possible, I would like to NOT actually establishing a
> connection to postgresql like if i used psql -c “select 1;”,
> to avoid connection overhead.

This

http://www.postgresql.org/docs/devel/static/libpq-connect.html

talks about ping functionality. Maybe you can use a tiny
custom piece of code ?

Karsten
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