Re: Crash dumps

On Wed, 06 Jul 2011 07:59:12 +0800, Craig Ringer wrote:
> On 5/07/2011 9:05 PM, Magnus Hagander wrote:
>> On Tue, Jul 5, 2011 at 15:02, Robert Haas<robertmhaas(at)gmail(dot)com>
>> wrote:
>>> On Mon, Jul 4, 2011 at 12:47 PM, Radosław Smogura
>>> <rsmogura(at)softperience(dot)eu> wrote:
>>>> I asked about crash reports becaus of at this time there was
>>>> thread about
>>>> crashing in live system.
>>>
>>> Yeah, I thought this was the result of that effort:
>
> [snip]
>
>> That crash dump is basically the windows equivalent of a coredump,
>> though. Just a different name...
>
> Yup, it's a cut-down core dump. In this case generated in-process by
> the crashing backend.
>
> It'd be nice to be able to generate the crash dump from
> out-of-process. Unfortunately, the automatic crash dump generation
> system on Windows doesn't appear to be available to system services
> running non-interactively. Not that I could see, anyway. As a result
> we had to trap the crashes within the crashing process and generate
> the dump from there. As previously stated, doing anything within a
> segfaulting process is unreliable, so it's not the best approach in
> the world.
>
> All I was saying in this thread is that it'd be nice to have a way
> for a crashing backend to request that another process capture
> diagnostic information from it before it exits with a fault, so it
> doesn't have to try to dump its self.
>
> As Tom said, though, anything like that is more likely to decrease
> the reliability of the overall system. You don't want a dead backend
> hanging around forever waiting for the postmaster to act on it, and
> you *really* don't want other backends still alive and potentially
> writing from shm that's in in who-knows-what state while the
> postmaster is busy fiddling with a crashed backend.
>
> So, overall, I think "dump a simple core and die as quickly as
> possible" is the best option. That's how it already works on UNIX,
> and
> all the win32 crash dump patches do is make it work on Windows too.
>
> --
> Craig Ringer
>
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Personally I will not send core dump to anyone, core dump may not only
contain sensible information from postmaster, but from other application
too.
Btw, I just take core dump form postmaster, I found there some dns
addresses I connected before from bash. Postamster should not see it.

I think IPC for fast shout down all backends and wait for report
processing is quite enaugh.

Regards,
Radosław Smogura