Re: backend hangs at sendto() and can't be terminated

n
etstat show nothing about the socket of the process,so I think the TCP
timeout took effect.so it is really wired.

Jov
blog: http:amutu.com/blog <http://amutu.com/blog>

2013/7/8 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>

> Merlin Moncure <mmoncure(at)gmail(dot)com> writes:
> > On Mon, Jul 8, 2013 at 4:56 AM, Jov <amutu(at)amutu(dot)com> wrote:
> >> my first post already try the pg_terminate_backend but failed:
> >> pg_terminate_backend return t but the backend still there.
>
> > possibly a kernel problem?
>
> The backend will keep trying to send data until the kernel informs it
> the connection is lost. (Anything else would be a bad idea.) So the
> real question here is why it's taking so long for the TCP stack to
> decide that the client is gone. I'm wondering what exactly you did
> to kill the psql session. Most ordinary ways of killing a process
> should result in closure of whatever connections it had open.
>
> If you'd lost network connectivity to the client, a TCP timeout on the
> order of an hour wouldn't be surprising. (If you feel this is too long,
> you can fool with the TCP keepalive parameters.) But it seems unlikely
> that that's what's happening here.
>
> regards, tom lane
>
>