Re: Assertion failure with barriers in parallel hash join

On Thu, Oct 1, 2020 at 8:08 PM Thomas Munro <thomas(dot)munro(at)gmail(dot)com> wrote:

> On Tue, Sep 29, 2020 at 9:12 PM Thomas Munro <thomas(dot)munro(at)gmail(dot)com>
> wrote:
> > On Tue, Sep 29, 2020 at 7:11 PM Michael Paquier <michael(at)paquier(dot)xyz>
> wrote:
> > > #2 0x00000000009027d2 in ExceptionalCondition
> > > (conditionName=conditionName(at)entry=0xa80846 "!barrier->static_party",
> >
> > > #4 0x0000000000682ebf in ExecParallelHashJoinNewBatch
> >
> > Thanks. Ohhh. I think I see how that condition was reached and what
> > to do about it, but I'll need to look more closely. I'm away on
> > vacation right now, and will update in a couple of days when I'm back
> > at a real computer.
>
> Here's a throw-away patch to add some sleeps that trigger the problem,
> and a first draft fix. I'll do some more testing of this next week
> and see if I can simplify it.
>

I was just taking a look at the patch and noticed the commit message
says:

> With unlucky timing and parallel_leader_participation off...

Is parallel_leader_participation being off required to reproduce the
issue?