Re: detecting a dead db not seeming to work

On Thu, 2004-08-26 at 15:57, Tom Lane wrote:
> Graeme Hinchliffe <graeme.hinchliffe@zeninternet.co.uk> writes:
> > However one of the tests I performed was to kill -9 the postmaster
> > process to see how it would handle that (assuming the same behaviour).
> > However nothing happens!  no segfault, no db connection failure etc.
>
> That's the intended behavior on postmaster crash.  It doesn't (and
> shouldn't) affect existing backends.

indeed, but I need to be able to see that it's dead so I can then try
and reconnect.  What is the name of the process that will be holding the
connection open? by kill -9 ing the process I am trying to simulate a
failure case.

> > If I kill my daemon which is trying to talk to it, postgres starts
> > without problem agian!
> > it's as though my daemon trying to talk to it is keeping the connection
> > open and preventing the db from being started!
>
> A new postmaster can't start until the last old backend is gone.  This
> is a necessary interlock to avoid data corruption.

But I kill -9 the postmaster, and I cannot start a fresh one, so my
process is sat in limbo, thinking it is talking to a db that isn't there
:).

Well I think so, although I suspect that some part of the db is still
there and running?

--
-----
Graeme Hinchliffe (BSc)
Core Internet Systems Designer
Zen Internet (http://www.zen.co.uk/)

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