Re: Query cancel seems to be broken in master since Oct 17

Magnus Hagander <magnus(at)hagander(dot)net> writes:
> On Tue, Oct 18, 2016 at 1:00 AM, Vladimir Sitnikov <
> sitnikov(dot)vladimir(at)gmail(dot)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

regards, tom lane