Re: Transaction timeout

Japin Li <japinli@hotmail.com>

From: Japin Li <japinli@hotmail.com>
To: Japin Li <japinli@hotmail.com>
Cc: Junwang Zhao <zhjwpku@gmail.com>, "Andrey M. Borodin" <x4mmm@yandex-team.ru>, 邱宇航 <iamqyh@gmail.com>, Fujii Masao <masao.fujii@oss.nttdata.com>, Andrey Borodin <amborodin86@gmail.com>, Andres Freund <andres@anarazel.de>, "Michael Paquier" <michael.paquier@gmail.com>, Nikolay Samokhvalov <samokhvalov@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>, pgsql-hackers@lists.postgresql.org
Date: 2023-12-23T02:40:32Z
Lists: pgsql-hackers
On Sat, 23 Dec 2023 at 08:32, Japin Li <japinli@hotmail.com> wrote:
> On Fri, 22 Dec 2023 at 23:30, Junwang Zhao <zhjwpku@gmail.com> wrote:
>> On Fri, Dec 22, 2023 at 10:44 PM Japin Li <japinli@hotmail.com> wrote:
>>>
>>>
>>> On Fri, 22 Dec 2023 at 22:37, Junwang Zhao <zhjwpku@gmail.com> wrote:
>>> > On Fri, Dec 22, 2023 at 10:25 PM Japin Li <japinli@hotmail.com> wrote:
>>> >> I try to set idle_in_transaction_session_timeout after begin transaction,
>>> >> it changes immediately, so I think transaction_timeout should also be take
>>> >> immediately.
>>> >
>>> > Ah, right, idle_in_transaction_session_timeout is set after the set
>>> > command finishes and before the backend send *ready for query*
>>> > to the client, so the value of the GUC is already set before
>>> > next command.
>>> >
>>>
>>> I mean, is it possible to set transaction_timeout before next comand?
>>>
>> Yeah, it's possible, set transaction_timeout in the when it first
>> goes into *idle in transaction* mode, see the attached files.
>>
>
> Thanks for updating the patch, LGTM.

Sorry for the noise!

Read the previous threads, I find why the author enable transaction_timeout
in start_xact_command().

The v15 patch cannot handle COMMIT AND CHAIN, see [1]. For example:

SET transaction_timeout TO '2s'; BEGIN; SELECT 1, pg_sleep(1); COMMIT AND CHAIN; SELECT 2, pg_sleep(1); COMMIT;

The transaction_timeout do not reset when executing COMMIT AND CHAIN.

[1] https://www.postgresql.org/message-id/a906dea1-76a1-4f26-76c5-a7efad3ef5b8%40oss.nttdata.com

--
Regrads,
Japin Li
ChengDu WenWu Information Technology Co., Ltd.



Commits

  1. Add TAP tests for timeouts

  2. Remove flaky isolation tests for timeouts

  3. Followup fixes for transaction_timeout

  4. Introduce transaction_timeout

  5. On systems that have setsid(2) (which should be just about everything except