Обсуждение: Re: pgsql: Use appropriate wait event when sending data in the apply worker

On Mon, Feb 6, 2023 at 11:40 PM Amit Kapila <akapila@postgresql.org> wrote:
> Use appropriate wait event when sending data in the apply worker.
>
> Currently, we reuse WAIT_EVENT_LOGICAL_PARALLEL_APPLY_STATE_CHANGE in the
> apply worker while sending data to the parallel apply worker via a shared
> memory queue. This is not appropriate as one won't be able to distinguish
> whether the worker is waiting for sending data or for the state change.
>
> To patch instead uses the wait event WAIT_EVENT_MQ_SEND which has been
> already used in blocking mode while sending data via a shared memory
> queue.

This is not right at all. You should invent a new wait state if you're
waiting in a new place.

-- 
Robert Haas
EDB: http://www.enterprisedb.com

On Thu, Feb 9, 2023 at 7:56 PM Robert Haas <robertmhaas@gmail.com> wrote:
>
> On Mon, Feb 6, 2023 at 11:40 PM Amit Kapila <akapila@postgresql.org> wrote:
> > Use appropriate wait event when sending data in the apply worker.
> >
> > Currently, we reuse WAIT_EVENT_LOGICAL_PARALLEL_APPLY_STATE_CHANGE in the
> > apply worker while sending data to the parallel apply worker via a shared
> > memory queue. This is not appropriate as one won't be able to distinguish
> > whether the worker is waiting for sending data or for the state change.
> >
> > To patch instead uses the wait event WAIT_EVENT_MQ_SEND which has been
> > already used in blocking mode while sending data via a shared memory
> > queue.
>
> This is not right at all. You should invent a new wait state if you're
> waiting in a new place.
>

This is a misunderstanding on my part to reuse the wait_event for a
similar kind of wait but I got your point and will take care of this.

-- 
With Regards,
Amit Kapila.