Re: zombie connections

On Fri, Apr 03, 2020 at 02:40:30PM +0200, Pavel Stehule wrote:
> pá 3. 4. 2020 v 14:30 odesílatel Robert Haas <robertmhaas(at)gmail(dot)com> napsal:
> >
> > Suppose that the server is executing a lengthy query, and the client
> > breaks the connection. The operating system will be aware that the
> > connection is no more, but PostgreSQL doesn't notice, because it's not
> > try to read from or write to the socket. It's not paying attention to
> > the socket at all. In theory, the query could be one that runs for a
> > million years and continue to chew up CPU and I/O, or at the very
> > least a connection slot, essentially forever. That's sad.
> >
> > I don't have a terribly specific idea about how to improve this, but
> > is there some way that we could, at least periodically, check the
> > socket to see whether it's dead? Noticing the demise of the client
> > after a configurable interval (maybe 60s by default?) would be
> > infinitely better than never.
> >
>
> + 1

+1 too, I already saw such behavior.

Maybe the postmaster could send some new PROCSIG SIGUSR1 signal to backends at
a configurable interval and let ProcessInterrupts handle it?