Re: Queries that should be canceled will get stuck on secure_write function

On 2021/08/24 0:26, Alvaro Herrera wrote:
> Aren't we talking about query cancellations that occur in response to a
> standby delay limit? Those aren't in response to user action. What I
> mean is that if the standby delay limit is exceeded, then we send a
> query cancel; we expect the standby to cancel its query at that time and
> then the primary can move on. But if the standby doesn't react, then we
> can have it terminate its connection.

+1

On 2021/08/24 3:45, Robert Haas wrote:
> On Mon, Aug 23, 2021 at 11:26 AM Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
>> Aren't we talking about query cancellations that occur in response to a
>> standby delay limit? Those aren't in response to user action.
>
> Oh, you're right. But I guess a similar problem could also occur in
> response to pg_terminate_backend(), no?

There seems no problem in that case because pg_terminate_backend() causes
a backend to set ProcDiePending to true in die() signal hander and
ProcessClientWriteInterrupt() called by secure_write() handles ProcDiePending.
No?

Regards,

--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION