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

On Wed, May 11, 2016 at 02:28:47PM +0200, Vik Fearing 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 ?
>
> That tiny custom piece of code would be this:
>
> http://www.postgresql.org/docs/current/static/app-pg-isready.html

That's what I had in mind :-)

Thanks,
Karsten
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