Re: more signals (was: Function to kill backend)

Magnus Hagander wrote:
> On top of this, we create a SystemV message queue used to pass down
> extended signals (should be supported on all systems that support sysv
> shared mem, and we require that..). We'd use the PID of the receiving
> backend as the message type, and pass the signal number as message
> contents.

I think we already have enough IPC uglyness without adding message
queues.  :-)

> To the user it would be exposed using "pg_ctl kill" (that we already
> have). Which can of course also send normal signals. So we'd say
> "*never* use kill -<antyhing> on a pg backend, always use 'pg_kill
> kill', oh, and never -9 anything".
> 
> 
> This is more or less how it's done on win32 today (only there we do it
> for all signals - and this can and shuold definitly not be used to
> change the behaviour of things like SIGTERM that you'd normally see
> happen in a unix environment, that would just be dangerous). The current
> win32 implementatino could just be extended to send a int32 instead of a
> byte across the IPC channel already established.
> 
> 
> Does this sound like a reasonable way to extend the available signals?
> Or is it adding unnecessary stuff?
> And finally, if this sounds like a decent idea, is it too big to slip in
> as a bugfix for the term_backend() stuff into 7.5?

At this point the big issue is terminating a backend session remotely. 
Let's get 7.5 out and see who else asks for it because right now I am
not even sure who wants it.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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