Horton

Thread

Commits

  1. Add a new wait state and use it when sending data in the apply worker.

  2. Use appropriate wait event when sending data in the apply worker.

  1. pgsql: Use appropriate wait event when sending data in the apply worker

    Amit Kapila <akapila@postgresql.org> — 2023-02-07T04:40:15Z

    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.

Author: Hou Zhijie
Reviewed-by: Kuroda Hayato, Amit Kapila
Discussion: https://postgr.es/m/OS0PR01MB57161C680B22E4C591628EE994DA9@OS0PR01MB5716.jpnprd01.prod.outlook.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/d9d7fe68d35e1e10c7c8276d07f5abf9c477cb13

Modified Files
--------------
src/backend/replication/logical/applyparallelworker.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

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

    Robert Haas <robertmhaas@gmail.com> — 2023-02-09T14:26:03Z

    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

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

    Amit Kapila <amit.kapila16@gmail.com> — 2023-02-10T02:06:25Z

    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.