Re: kill -KILL: What happens?

On Thu, Jan 13, 2011 at 3:01 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> On Thu, Jan 13, 2011 at 2:45 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>> I wonder whether we could have some sort of latch-like counter that
>>> would count the number of active backends and deliver signals when the
>>> count went to zero.  However, if the goal is to defend against random
>>> applications of SIGKILL, there's probably no way to make this reliable
>>> in userspace.
>
>> I don't think you can get there 100%.  We could, however, make a rule
>> that when a background process fails a PostmasterIsAlive() check, it
>> sends SIGQUIT to everyone it can find in the ProcArray, which would at
>> least ensure a timely exit in most real-world cases.
>
> You're going in the wrong direction there: we're trying to have the
> system remain sane when the postmaster crashes, not see how quickly
> it can screw up every remaining session.

I strongly believe you're in the minority on that one, for the same
reasons that I don't think most people would agree with your notion of
what should be the default shutdown mode. A database that can't
accept new connections is a liability, not an asset.

--
Robert Haas
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