Re: Do we need pre-allocate WAL files during end-of-recovery checkpoint?

Поиск
Список
Период
Сортировка
От SATYANARAYANA NARLAPURAM
Тема Re: Do we need pre-allocate WAL files during end-of-recovery checkpoint?
Дата
Msg-id CAHg+QDdzqphWqo_ijFiDE+XLdKuNG=BLuLHfOK+fXActKkVOJw@mail.gmail.com
обсуждение исходный текст
Ответ на Do we need pre-allocate WAL files during end-of-recovery checkpoint?  (Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>)
Ответы Re: Do we need pre-allocate WAL files during end-of-recovery checkpoint?  ("Bossart, Nathan" <bossartn@amazon.com>)
Re: Do we need pre-allocate WAL files during end-of-recovery checkpoint?  (Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>)
Список pgsql-hackers
If the segment size is 16MB it shouldn't take much time but higher segment values this can be a problem. But again, the current segment has to be filled 75% to precreate new one. I am not sure how much we gain. Do you have some numbers with different segment sizes?

On Mon, Dec 6, 2021 at 4:51 AM Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com> wrote:
Hi,

The function PreallocXlogFiles doesn't get called during
end-of-recovery checkpoint in CreateCheckPoint, see [1]. The server
becomes operational after the end-of-recovery checkpoint and may need
WAL files. However, I'm not sure how beneficial it is going to be if
the WAL is pre-allocated (as PreallocXlogFiles just allocates only 1
extra WAL file).

Thoughts?

[1]
    /*
     * An end-of-recovery checkpoint is really a shutdown checkpoint, just
     * issued at a different time.
     */
    if (flags & (CHECKPOINT_IS_SHUTDOWN | CHECKPOINT_END_OF_RECOVERY))
        shutdown = true;
    else
        shutdown = false;

    /*
     * Make more log segments if needed.  (Do this after recycling old log
     * segments, since that may supply some of the needed files.)
     */
    if (!shutdown)
        PreallocXlogFiles(recptr, checkPoint.ThisTimeLineID);

Regards,
Bharath Rupireddy.


В списке pgsql-hackers по дате отправления:

Предыдущее
От: Tom Lane
Дата:
Сообщение: Re: PostgreSQL server: authentication method 10 not supported
Следующее
От: "Bossart, Nathan"
Дата:
Сообщение: Re: parse_subscription_options - suggested improvements