From: Reza Taheri <rtaheri@vmware.com>
To: Ryan Johnson <ryan.johnson@cs.utoronto.ca>,
 "pgsql-performance@postgresql.org" <pgsql-performance@postgresql.org>
Subject: Re: High rate of transaction failure with the Serializable
 Isolation Level
Thread-Topic: High rate of transaction failure with the Serializable
 Isolation Level
Thread-Index: AQHPqFHVx3JypHx58U+0ZXroXUnibJuyxa9g
Date: Sat, 26 Jul 2014 19:55:11 +0000
Message-ID: <20fd404f0e9c42f1b9847c35c1dc546c@EX13-MBX-013.vmware.com>
References: <ded604822b28427a80b0751a973e4258@EX13-MBX-013.vmware.com>
 <53D0923B.7050501@2ndquadrant.com>
 <93e2642196e646adbcf5780d3cf54685@EX13-MBX-013.vmware.com>
 <53D1B31B.8070909@2ndquadrant.com>
 <80d78b6fec064f14aa025c1ca86c8099@EX13-MBX-013.vmware.com>
 <53D2CDA3.8050707@cs.utoronto.ca>
In-Reply-To: <53D2CDA3.8050707@cs.utoronto.ca>
Accept-Language: en-US
Content-Language: en-US
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Precedence: bulk
Sender: pgsql-performance-owner@postgresql.org

Hi Ryan,
That's a very good point. We are looking at dbt5. One question: what throug=
hput rate, and how many threads of execution did you use for dbt5?  The fai=
lure rates I reported were at ~120 tps with 15 trade-result threads.

Thanks,
Reza

> -----Original Message-----
> From: pgsql-performance-owner@postgresql.org [mailto:pgsql-
> performance-owner@postgresql.org] On Behalf Of Ryan Johnson
> Sent: Friday, July 25, 2014 2:36 PM
> To: pgsql-performance@postgresql.org
> Subject: Re: High rate of transaction failure with the Serializable Isola=
tion
> Level
>=20
> On 25/07/2014 2:58 PM, Reza Taheri wrote:
> > Hi Craig,
> >
> >> According to the attached SQL, each frame is a separate phase in the
> operation and performs many different operations.
> >> There's a *lot* going on here, so identifying possible
> >> interdependencies isn't something I can do in a ten minute skim read o=
ver
> my morning coffee.
> > You didn't think I was going to bug you all with a trivial problem,
> > did you? :-) :-)
> >
> > Yes, I am going to have to take an axe to the code and see what pops ou=
t.
> Just to put this in perspective, the transaction flow and its statements =
are
> borrowed verbatim from the TPC-E benchmark. There have been dozens of
> TPC-E disclosures with MS SQL Server, and there are Oracle and DB2 kits t=
hat,
> although not used in public disclosures for various non-technical reasons=
, are
> used internally in by the DB and server companies. These 3 products, and
> perhaps more, were used extensively in the prototyping phase of TPC-E.
> >
> > So, my hope is that if there is a "previously unidentified interdepende=
ncy
> between transactions" as you point out, it will be due to a mistake we ma=
de
> in coding this for PGSQL. Otherwise, we will have a hard time convincing =
all
> the council member companies that we need to change the schema or the
> business logic to make the kit work with PGSQL.
> >
> > Just pointing out my uphill battle!!
> You might compare against dbt-5 [1], just to see if the same problem occu=
rs. I
> didn't notice such high abort rates when I ran that workload a few weeks
> ago. Just make sure to use the latest commit, because the "released" vers=
ion
> has fatal bugs.
>=20
> [1]
> https://urldefense.proofpoint.com/v1/url?u=3Dhttps://github.com/petergeog
> hegan/dbt5&k=3DoIvRg1%2BdGAgOoM1BIlLLqw%3D%3D%0A&r=3Db9TKmA0CPjr
> oD2HLPTHU27nI9PJr8wgKO2rU9QZyZZU%3D%0A&m=3D6E%2F9fWJPMGjpMyP
> xtY0nsamLLW%2FNsTXu7FP9Wzauj10%3D%0A&s=3Db3f269216d419410f3f07bb
> 774a27b7d377744c9d423df52a3e62324d9279958
>=20
> Ryan
>=20
>=20
>=20
> --
> Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
> To make changes to your subscription:
> https://urldefense.proofpoint.com/v1/url?u=3Dhttp://www.postgresql.org/m
> ailpref/pgsql-
> performance&k=3DoIvRg1%2BdGAgOoM1BIlLLqw%3D%3D%0A&r=3Db9TKmA0CP
> jroD2HLPTHU27nI9PJr8wgKO2rU9QZyZZU%3D%0A&m=3D6E%2F9fWJPMGjpMy
> PxtY0nsamLLW%2FNsTXu7FP9Wzauj10%3D%0A&s=3D45ab94ce068dbe28956af
> 8bb3f999e9a91138dd1e3c3345c036e87e902da1ef1


--=20
Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance