Received: from localhost (unknown [200.46.208.211]) by mail.postgresql.org (Postfix) with ESMTP id 6B356632BA0 for ; Mon, 16 Mar 2009 15:44:55 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.208.211]) (amavisd-maia, port 10024) with ESMTP id 07354-06 for ; Mon, 16 Mar 2009 15:44:45 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from EXHUB018-3.exch018.msoutlookonline.net (exhub018-3.exch018.msoutlookonline.net [64.78.17.18]) by mail.postgresql.org (Postfix) with ESMTP id BF251634177 for ; Mon, 16 Mar 2009 15:44:44 -0300 (ADT) Received: from EXVMBX018-1.exch018.msoutlookonline.net ([64.78.17.47]) by EXHUB018-3.exch018.msoutlookonline.net ([64.78.17.18]) with mapi; Mon, 16 Mar 2009 11:44:37 -0700 From: Scott Carey To: Kevin Grittner , "david@lang.hm" , Kevin Grittner CC: Robert Haas , Greg Smith , "pgsql-performance@postgresql.org" , Tom Lane , "Jignesh K. Shah" Date: Mon, 16 Mar 2009 11:44:34 -0700 Subject: Re: Proposal of tunable fix for scalability of 8.4 Thread-Topic: [PERFORM] Proposal of tunable fix for scalability of 8.4 Thread-Index: AcmmV8m+ArnbHJP2SZmPKVZGDc/GTgAD3YfO Message-ID: In-Reply-To: <49BE3DC3.EE98.0025.0@wicourts.gov> Accept-Language: en-US Content-Language: en X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_C5E3EC223580scottrichrelevancecom_" MIME-Version: 1.0 X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.001 tagged_above=0 required=5 tests=AWL=-0.000, HTML_MESSAGE=0.001 X-Spam-Level: X-Archive-Number: 200903/214 X-Sequence-Number: 33136 --_000_C5E3EC223580scottrichrelevancecom_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Note, some have mentioned that my client breaks inline formatting. My only= comment is after Kevin's signature below: On 3/16/09 9:53 AM, "Kevin Grittner" wrote: I wrote: > One more reason this point is an interesting one is that it is one > that gets *worse* with the suggested patch, if only by half a percent. > > Without: > > 600: 80: Medium Throughput: 82632.000 Avg Medium Resp: 0.005 > > with: > > 600: 80: Medium Throughput: 82241.000 Avg Medium Resp: 0.005 Oops. A later version: > Redid the test with - waking up all waiters irrespective of shared, > exclusive > 600: 80: Medium Throughput: 82920.000 Avg Medium Resp: 0.005 The one that showed the decreased performance at 800 was: > a modified Fix (not the original one that I proposed but something > that works like a heart valve : Opens and shuts to minimum > default way thus controlling how many waiters are waked up ) -Kevin All three of those are probably within the margin of error of the measureme= nt. We would need to run the same test 3 or 4 times to gauge its variance b= efore concluding much. --_000_C5E3EC223580scottrichrelevancecom_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: [PERFORM] Proposal of tunable fix for scalability of 8.4 Note, some have mentioned that my client breaks inline formatting. &n= bsp;My only comment is after Kevin’s signature below:

On 3/16/09 9:53 AM, "Kevin Grittner" <Kevin.Grittner@wicourts.gov> wrote:

I wrote:
> One more reason this point is an interesting one is that it is one
> that gets *worse* with the suggested patch, if only by half a
percent.
>
> Without:
>
> 600: 80: Medium Throughput: 82632.000 Avg Medium Resp: 0.005
>
> with:
>
> 600: 80: Medium Throughput: 82241.000 Avg Medium Resp: 0.005

Oops.  A later version:

> Redid the test with - waking up all waiters irrespective of shared, > exclusive

> 600: 80: Medium Throughput: 82920.000 Avg Medium Resp: 0.005

The one that showed the decreased performance at 800 was:

> a modified Fix (not the original one that I proposed but something
> that works like a heart valve : Opens and shuts to minimum
> default way thus  controlling how many waiters are waked up )

-Kevin