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* Re: [kris@obsecurity.org: Progress on scaling of FreeBSD on 8 CPU systems]
@ 2007-03-02 15:01 Alvaro Herrera <alvherre@commandprompt.com>
0 siblings, 2 replies; 11+ messages in thread
From: Alvaro Herrera @ 2007-03-02 15:01 UTC (permalink / raw)
To: Jim C. Nasby <decibel@decibel.org>; +Cc: pgsql-performance
> From: Kris Kennaway <kris@obsecurity.org>
> We have recently made significant progress on optimizing for MySQL
> running on an 8-core amd64 system. The graph of results may be found
> here:
>
> http://www.freebsd.org/~kris/scaling/scaling.png
>
> This shows the graph of MySQL transactions/second performed by a
> multi-threaded client workload against a local MySQL database with
> varying numbers of client threads, with identically configured FreeBSD
> and Linux systems on the same machine.
Interesting -- the MySQL/Linux graph is very similar to the graphs from
the .nl magazine posted last year. I think this suggests that the
"MySQL deficiency" was rather a performance bug in Linux, not in MySQL
itself ...
--
Alvaro Herrera http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.
^ permalink raw reply [nested|flat] 11+ messages in thread
* Re: [kris@obsecurity.org: Progress on scaling of FreeBSD on 8 CPU systems]
@ 2007-03-02 15:49 Arjen van der Meijden <acmmailing@tweakers.net>
parent: Alvaro Herrera <alvherre@commandprompt.com>
1 sibling, 1 reply; 11+ messages in thread
From: Arjen van der Meijden @ 2007-03-02 15:49 UTC (permalink / raw)
To: Jim C. Nasby <decibel@decibel.org>; pgsql-performance
Alvaro Herrera wrote:
> Interesting -- the MySQL/Linux graph is very similar to the graphs from
> the .nl magazine posted last year. I think this suggests that the
> "MySQL deficiency" was rather a performance bug in Linux, not in MySQL
> itself ...
The latest benchmark we did was both with Solaris and Linux on the same
box, both showed such a drop. So I doubt its "not in MySQL", although it
might be possible to fix the load MySQL's usage pattern poses on a
system, via the OS. And since MySQL 5.0.32 is less bad than 4.1.22 on
that system. We didn't have time to test 5.0.25 again, but .32 scaled
better, so at least some of the scaling issues where actually fixed in
MySQL itself.
Best regards,
Arjen
^ permalink raw reply [nested|flat] 11+ messages in thread
* Re: [kris@obsecurity.org: Progress on scaling of FreeBSD on 8 CPU systems]
@ 2007-03-02 16:35 Scott Marlowe <smarlowe@g2switchworks.com>
parent: Alvaro Herrera <alvherre@commandprompt.com>
1 sibling, 0 replies; 11+ messages in thread
From: Scott Marlowe @ 2007-03-02 16:35 UTC (permalink / raw)
To: Alvaro Herrera <alvherre@commandprompt.com>; +Cc: Jim C. Nasby <decibel@decibel.org>; pgsql-performance
On Fri, 2007-03-02 at 09:01, Alvaro Herrera wrote:
> > From: Kris Kennaway <kris@obsecurity.org>
>
> > We have recently made significant progress on optimizing for MySQL
> > running on an 8-core amd64 system. The graph of results may be found
> > here:
> >
> > http://www.freebsd.org/~kris/scaling/scaling.png
> >
> > This shows the graph of MySQL transactions/second performed by a
> > multi-threaded client workload against a local MySQL database with
> > varying numbers of client threads, with identically configured FreeBSD
> > and Linux systems on the same machine.
>
> Interesting -- the MySQL/Linux graph is very similar to the graphs from
> the .nl magazine posted last year. I think this suggests that the
> "MySQL deficiency" was rather a performance bug in Linux, not in MySQL
> itself ...
I rather think it's a combination of how MySQL does things and Linux not
being optimized to handle that situation.
It may well be that the fixes to BSD have simply moved the point at
which performance dives off quickly from 50 connections to 300 or
something.
I'd really like to see freebsd tested on the 32 thread Sun CPU that had
such horrible performance with linux, and with many more threads to see
if there's still a cliff there somewhere, and to see where postgresql's
cliff would be as well. After all, the most interesting part of
performance graphs are the ones you see when the system is heading into
overload.
^ permalink raw reply [nested|flat] 11+ messages in thread
* Re: [kris@obsecurity.org: Progress on scaling of FreeBSD on 8 CPU systems]
@ 2007-03-05 10:52 Arjen van der Meijden <acmmailing@tweakers.net>
parent: Arjen van der Meijden <acmmailing@tweakers.net>
0 siblings, 2 replies; 11+ messages in thread
From: Arjen van der Meijden @ 2007-03-05 10:52 UTC (permalink / raw)
To: pgsql-performance
And here is that latest benchmark we did, using a 8 dual core opteron
Sun Fire x4600. Unfortunately PostgreSQL seems to have some difficulties
scaling over 8 cores, but not as bad as MySQL.
http://tweakers.net/reviews/674
Best regards,
Arjen
Arjen van der Meijden wrote:
> Alvaro Herrera wrote:
>> Interesting -- the MySQL/Linux graph is very similar to the graphs from
>> the .nl magazine posted last year. I think this suggests that the
>> "MySQL deficiency" was rather a performance bug in Linux, not in MySQL
>> itself ...
>
> The latest benchmark we did was both with Solaris and Linux on the same
> box, both showed such a drop. So I doubt its "not in MySQL", although it
> might be possible to fix the load MySQL's usage pattern poses on a
> system, via the OS. And since MySQL 5.0.32 is less bad than 4.1.22 on
> that system. We didn't have time to test 5.0.25 again, but .32 scaled
> better, so at least some of the scaling issues where actually fixed in
> MySQL itself.
>
> Best regards,
>
> Arjen
>
> ---------------------------(end of broadcast)---------------------------
> TIP 7: You can help support the PostgreSQL project by donating at
>
> http://www.postgresql.org/about/donate
>
^ permalink raw reply [nested|flat] 11+ messages in thread
* Re: [kris@obsecurity.org: Progress on scaling of FreeBSD on 8 CPU systems]
@ 2007-03-05 11:44 Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>
parent: Arjen van der Meijden <acmmailing@tweakers.net>
1 sibling, 1 reply; 11+ messages in thread
From: Stefan Kaltenbrunner @ 2007-03-05 11:44 UTC (permalink / raw)
To: Arjen van der Meijden <acmmailing@tweakers.net>; +Cc: pgsql-performance
Arjen van der Meijden wrote:
> And here is that latest benchmark we did, using a 8 dual core opteron
> Sun Fire x4600. Unfortunately PostgreSQL seems to have some difficulties
> scaling over 8 cores, but not as bad as MySQL.
>
> http://tweakers.net/reviews/674
ouch - do I read that right that even after tom's fixes for the
"regressions" in 8.2.0 we are still 30% slower then the -HEAD checkout
from the middle of the 8.2 development cycle ?
Stefan
^ permalink raw reply [nested|flat] 11+ messages in thread
* Re: [kris@obsecurity.org: Progress on scaling of FreeBSD on 8 CPU systems]
@ 2007-03-05 11:49 Richard Huxton <dev@archonet.com>
parent: Arjen van der Meijden <acmmailing@tweakers.net>
1 sibling, 0 replies; 11+ messages in thread
From: Richard Huxton @ 2007-03-05 11:49 UTC (permalink / raw)
To: Arjen van der Meijden <acmmailing@tweakers.net>; +Cc: pgsql-performance
Arjen van der Meijden wrote:
> And here is that latest benchmark we did, using a 8 dual core opteron
> Sun Fire x4600. Unfortunately PostgreSQL seems to have some difficulties
> scaling over 8 cores, but not as bad as MySQL.
>
> http://tweakers.net/reviews/674
Hmm - interesting reading as always Arjen.
Thanks for the notice on this.
--
Richard Huxton
Archonet Ltd
^ permalink raw reply [nested|flat] 11+ messages in thread
* Re: [kris@obsecurity.org: Progress on scaling of FreeBSD on 8 CPU systems]
@ 2007-03-05 11:51 Arjen van der Meijden <acmmailing@tweakers.net>
parent: Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>
0 siblings, 1 reply; 11+ messages in thread
From: Arjen van der Meijden @ 2007-03-05 11:51 UTC (permalink / raw)
To: Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>; +Cc: pgsql-performance
Stefan Kaltenbrunner wrote:
> ouch - do I read that right that even after tom's fixes for the
> "regressions" in 8.2.0 we are still 30% slower then the -HEAD checkout
> from the middle of the 8.2 development cycle ?
Yes, and although I tested about 17 different cvs-checkouts, Tom and I
weren't really able to figure out where "it" happened. So its a bit of a
mystery why the performance is so much worse.
Best regards,
Arjen
^ permalink raw reply [nested|flat] 11+ messages in thread
* Re: [kris@obsecurity.org: Progress on scaling of FreeBSD on 8 CPU systems]
@ 2007-03-05 20:17 Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>
parent: Arjen van der Meijden <acmmailing@tweakers.net>
0 siblings, 1 reply; 11+ messages in thread
From: Stefan Kaltenbrunner @ 2007-03-05 20:17 UTC (permalink / raw)
To: Arjen van der Meijden <acmmailing@tweakers.net>; +Cc: pgsql-performance
Arjen van der Meijden wrote:
> Stefan Kaltenbrunner wrote:
>> ouch - do I read that right that even after tom's fixes for the
>> "regressions" in 8.2.0 we are still 30% slower then the -HEAD checkout
>> from the middle of the 8.2 development cycle ?
>
> Yes, and although I tested about 17 different cvs-checkouts, Tom and I
> weren't really able to figure out where "it" happened. So its a bit of a
> mystery why the performance is so much worse.
double ouch - losing that much in performance without an idea WHY it
happened is really unfortunate :-(
Stefan
^ permalink raw reply [nested|flat] 11+ messages in thread
* Re: [kris@obsecurity.org: Progress on scaling of FreeBSD on 8 CPU systems]
@ 2007-03-05 20:38 Tom Lane <tgl@sss.pgh.pa.us>
parent: Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>
0 siblings, 2 replies; 11+ messages in thread
From: Tom Lane @ 2007-03-05 20:38 UTC (permalink / raw)
To: Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>; +Cc: Arjen van der Meijden <acmmailing@tweakers.net>; pgsql-performance
Stefan Kaltenbrunner <stefan@kaltenbrunner.cc> writes:
> Arjen van der Meijden wrote:
>> Stefan Kaltenbrunner wrote:
>>> ouch - do I read that right that even after tom's fixes for the
>>> "regressions" in 8.2.0 we are still 30% slower then the -HEAD checkout
>>> from the middle of the 8.2 development cycle ?
>>
>> Yes, and although I tested about 17 different cvs-checkouts, Tom and I
>> weren't really able to figure out where "it" happened. So its a bit of a
>> mystery why the performance is so much worse.
> double ouch - losing that much in performance without an idea WHY it
> happened is really unfortunate :-(
Keep in mind that Arjen's test exercises some rather narrow scenarios;
IIRC its performance is mostly determined by some complicated
bitmap-indexscan cases. So that "30% slower" bit certainly doesn't
represent an across-the-board figure. As best I can tell, the decisions
the planner happened to be making in late June were peculiarly nicely
suited to his test, but not so much for other cases.
regards, tom lane
^ permalink raw reply [nested|flat] 11+ messages in thread
* Re: [kris@obsecurity.org: Progress on scaling of FreeBSD on 8 CPU systems]
@ 2007-03-05 20:50 Arjen van der Meijden <acmmailing@tweakers.net>
parent: Tom Lane <tgl@sss.pgh.pa.us>
1 sibling, 0 replies; 11+ messages in thread
From: Arjen van der Meijden @ 2007-03-05 20:50 UTC (permalink / raw)
To: Tom Lane <tgl@sss.pgh.pa.us>; +Cc: Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>; pgsql-performance
On 5-3-2007 21:38 Tom Lane wrote:
> Keep in mind that Arjen's test exercises some rather narrow scenarios;
> IIRC its performance is mostly determined by some complicated
> bitmap-indexscan cases. So that "30% slower" bit certainly doesn't
> represent an across-the-board figure. As best I can tell, the decisions
> the planner happened to be making in late June were peculiarly nicely
> suited to his test, but not so much for other cases.
True, its not written as a database-comparison-test, but as a
platform-comparison test. As I showed you back then, there where indeed
querytypes faster on the final version (I still have that database of
executed queries on dev and 8.2 rc1), especially after your three
patches. Still, its a pitty that both the general performance and
scalability seem to be worse on these platforms.
Best regards,
Arjen
^ permalink raw reply [nested|flat] 11+ messages in thread
* Re: [kris@obsecurity.org: Progress on scaling of FreeBSD on 8 CPU systems]
@ 2007-03-07 18:48 Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>
parent: Tom Lane <tgl@sss.pgh.pa.us>
1 sibling, 0 replies; 11+ messages in thread
From: Stefan Kaltenbrunner @ 2007-03-07 18:48 UTC (permalink / raw)
To: Tom Lane <tgl@sss.pgh.pa.us>; +Cc: Arjen van der Meijden <acmmailing@tweakers.net>; pgsql-performance
Tom Lane wrote:
> Stefan Kaltenbrunner <stefan@kaltenbrunner.cc> writes:
>> Arjen van der Meijden wrote:
>>> Stefan Kaltenbrunner wrote:
>>>> ouch - do I read that right that even after tom's fixes for the
>>>> "regressions" in 8.2.0 we are still 30% slower then the -HEAD checkout
>>>> from the middle of the 8.2 development cycle ?
>>> Yes, and although I tested about 17 different cvs-checkouts, Tom and I
>>> weren't really able to figure out where "it" happened. So its a bit of a
>>> mystery why the performance is so much worse.
>
>> double ouch - losing that much in performance without an idea WHY it
>> happened is really unfortunate :-(
>
> Keep in mind that Arjen's test exercises some rather narrow scenarios;
> IIRC its performance is mostly determined by some complicated
> bitmap-indexscan cases. So that "30% slower" bit certainly doesn't
> represent an across-the-board figure. As best I can tell, the decisions
> the planner happened to be making in late June were peculiarly nicely
> suited to his test, but not so much for other cases.
understood - I was not trying to imply that we suffer a 30% performance
drop overall.
But still it means we know about a set of queries that we once could
handle faster than we can now ...
Stefan
^ permalink raw reply [nested|flat] 11+ messages in thread
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2007-03-02 15:01 Re: [kris@obsecurity.org: Progress on scaling of FreeBSD on 8 CPU systems] Alvaro Herrera <alvherre@commandprompt.com>
2007-03-02 15:49 ` Arjen van der Meijden <acmmailing@tweakers.net>
2007-03-05 10:52 ` Arjen van der Meijden <acmmailing@tweakers.net>
2007-03-05 11:44 ` Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>
2007-03-05 11:51 ` Arjen van der Meijden <acmmailing@tweakers.net>
2007-03-05 20:17 ` Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>
2007-03-05 20:38 ` Tom Lane <tgl@sss.pgh.pa.us>
2007-03-05 20:50 ` Arjen van der Meijden <acmmailing@tweakers.net>
2007-03-07 18:48 ` Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>
2007-03-05 11:49 ` Richard Huxton <dev@archonet.com>
2007-03-02 16:35 ` Scott Marlowe <smarlowe@g2switchworks.com>
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