Re: Re: [COMMITTERS] pgsql: Add some isolation tests for deadlock detection and resolution.

From: Robert Haas <robertmhaas(at)gmail(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Re: [COMMITTERS] pgsql: Add some isolation tests for deadlock detection and resolution.
Date: 2016-02-11 17:11:26
Message-ID: CA+TgmoYFg+ut1OOHfjCGgzpZtrbZ-nTEf8wQ_4+oVKO+PudFjQ@mail.gmail.com
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On Thu, Feb 11, 2016 at 12:04 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> I wrote:
>> No, because the machines that are failing are showing a "<waiting ...>"
>> annotation that your reference output *doesn't* have. I think what is
>> actually happening is that these machines are seeing the process as
>> waiting and reporting it, whereas on your machine the backend detects
>> the deadlock and completes the query (with an error) before
>> isolationtester realizes that the process is waiting.
>
> I confirmed this theory by the expedient of changing the '10ms' setting
> in the test script to 1ms (which worked) and 100ms (which did not, on
> the same machine).
>
> I've committed an update that adjusts the timeouts to hopefully ensure
> that isolationtester always sees the query as blocked before the deadlock
> detector unblocks it; which seems like the behavior we want to test for,
> anyway.

Thanks. I really appreciate it.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

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