Re: Query cancel seems to be broken in master since Oct 17 - Mailing list pgsql-hackers

From Heikki Linnakangas
Subject Re: Query cancel seems to be broken in master since Oct 17
Date
Msg-id 3c3f224d-d7c4-30af-b3b9-d77a0525ba44@iki.fi
Whole thread Raw
In response to Re: Query cancel seems to be broken in master since Oct 17  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Query cancel seems to be broken in master since Oct 17  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On 10/18/2016 04:13 PM, Tom Lane wrote:
> Magnus Hagander <magnus@hagander.net> writes:
>> On Tue, Oct 18, 2016 at 1:00 AM, Vladimir Sitnikov <
>> sitnikov.vladimir@gmail.com> wrote:
>>> The test executes "select pg_sleep(10)" and tries to cancel it. In recent
>>> master builds, cancel seems to be ignored, and the statement lasts for 10
>>> seconds.
>
>> My guess is it's related to this:
>> https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=9e083fd4683294f41544e6d0d72f6e258ff3a77c
>> That's certainly not intended to break things, but that was changed on Oct
>> 17 and it relates to cancel keys.
>> What platform does the postgres server run on? Can can you check if query
>> cancel works on libpq or if it's completely broken?
>
> I can confirm that query cancel is broken in HEAD on RHEL6.
>
> regression=# select pg_sleep(10);
> ^CCancel request sent
> ... nothing happens for the balance of the 10 seconds ...
> regression=#
>
> There's a smoking gun in the postmaster log:
>
> 2016-10-18 09:10:34.547 EDT [18502] LOG:  wrong key in cancel request for process 18491

Ok, I've reverted that commit for now. It clearly needs more thought, 
because of this, and the pademelon failure discussed on the other thread.

- Heikki




pgsql-hackers by date:

Previous
From: Andreas Joseph Krogh
Date:
Subject: Move pg_largeobject to a different tablespace *without* turning on system_table_mods.
Next
From: Merlin Moncure
Date:
Subject: Re: emergency outage requiring database restart