Re: backend hangs at immediate shutdown (Re: Back-branch update releases coming in a couple weeks) - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: backend hangs at immediate shutdown (Re: Back-branch update releases coming in a couple weeks)
Date
Msg-id 20130622172348.GB4051@eldon.alvh.no-ip.org
Whole thread Raw
In response to Re: backend hangs at immediate shutdown (Re: Back-branch update releases coming in a couple weeks)  ("MauMau" <maumau307@gmail.com>)
Responses Re: backend hangs at immediate shutdown (Re: Back-branch update releases coming in a couple weeks)
List pgsql-hackers
MauMau escribió:

> Are you suggesting simplifying the following part in ServerLoop()?
> I welcome the idea if this condition becomes simpler.  However, I
> cannot imagine how.

>  if (AbortStartTime > 0 &&  /* SIGKILL only once */
>   (Shutdown == ImmediateShutdown || (FatalError && !SendStop)) &&
>   now - AbortStartTime >= 10)
>  {
>   SignalAllChildren(SIGKILL);
>   AbortStartTime = 0;
>  }

Yes, that's what I'm suggesting.  I haven't tried coding it yet.

> I thought of adding some new state of pmState for some reason (that
> might be the same as your idea).
> But I refrained from doing that, because pmState has already many
> states.  I was afraid adding a new pmState value for this bug fix
> would complicate the state management (e.g. state transition in
> PostmasterStateMachine()).  In addition, I felt PM_WAIT_BACKENDS was
> appropriate because postmaster is actually waiting for backends to
> terminate after sending SIGQUIT.  The state name is natural.

Well, a natural state name is of no use if we're using it to indicate
two different states, which I think is what would be happening here.
Basically, with your patch, PM_WAIT_BACKENDS means two different things
depending on AbortStartTime.

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services



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