From oracle-l-bounce@freelists.org Sat Jul 16 17:06:13 2005 Return-Path: Received: from air891.startdedicated.com (root@localhost) by orafaq.com (8.12.10/8.12.10) with ESMTP id j6GM6C4V021788 for ; Sat, 16 Jul 2005 17:06:12 -0500 X-ClientAddr: 206.53.239.180 Received: from turing.freelists.org (freelists-180.iquest.net [206.53.239.180]) by air891.startdedicated.com (8.12.10/8.12.10) with ESMTP id j6GM64IP021777 for ; Sat, 16 Jul 2005 17:06:04 -0500 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id A31E41CBFB3; Sat, 16 Jul 2005 17:06:03 -0500 (EST) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 31045-05; Sat, 16 Jul 2005 17:06:03 -0500 (EST) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 19E2C1CBB38; Sat, 16 Jul 2005 17:06:03 -0500 (EST) X-MimeOLE: Produced By Microsoft Exchange V6.5.7226.0 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C58A52.4D2E3ACB" Subject: RE: "wait for scn from all nodes" wait in RAC Date: Sat, 16 Jul 2005 15:04:13 -0700 Message-ID: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: "wait for scn from all nodes" wait in RAC Thread-Index: AcWJebRHC7FnOZ/0TfGrHgDqJCFMLQABGL7QACn8AkAACxXcQA== From: "Kevin Closson" To: , , X-archive-position: 22570 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-To: oracle-l-bounce@freelists.org X-original-sender: kevinc@polyserve.com Precedence: normal Reply-To: kevinc@polyserve.com X-list: oracle-l X-Virus-Scanned: by amavisd-new-20030616-p9 (Debian) at avenirtech.net X-mailscan-MailScanner-Information: Please contact the ISP for more information X-mailscan-MailScanner: Found to be clean X-MailScanner-From: oracle-l-bounce@freelists.org X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on air891.startdedicated.com X-Spam-Status: No, hits=-4.6 required=5.0 tests=AWL,BAYES_00,HTML_60_70, HTML_FONTCOLOR_BLUE,HTML_FONTCOLOR_RED,HTML_FONTCOLOR_UNKNOWN, HTML_MESSAGE autolearn=no version=2.63 ------_=_NextPart_001_01C58A52.4D2E3ACB Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable > roundtrip for the confirmation of the SCN so that the LGWR can write the redo. We are using three private gigabit interconnects and in theory there =20 > enough bandwidth available to the IC path.=20 =20 =20 =20 bandwidth of the interconnect is most likely not a problem. Latency? Perhaps. Processor spikes/saturation on certain nodes, more likely. =20 =20 =20 =20 =20 =20 Amir ________________________________ From: oracle-l-bounce@freelists.org [mailto:oracle-l-bounce@freelists.org] On Behalf Of Cary Millsap Sent: Friday, July 15, 2005 4:47 PM To: oracle-l@freelists.org Subject: RE: "wait for scn from all nodes" wait in RAC =09 =09 Amir, =20 Only you can tell us whether the issue is of legitimate concern, right? :-) =20 Is the event a dominant contributor to the response time of an important business task? =20 Cary Millsap Hotsos Enterprises, Ltd. http://www.hotsos.com Nullius in verba =09 Visit www.hotsos.com for curriculum and schedule details... =09 ________________________________ From: oracle-l-bounce@freelists.org [mailto:oracle-l-bounce@freelists.org] On Behalf Of Hameed, Amir Sent: Friday, July 15, 2005 3:14 PM To: oracle-l@freelists.org Subject: "wait for scn from all nodes" wait in RAC =20 Does anyone know what this wait (wait for scn from all nodes) is about in RAC. We are currently running a test on a two-node RAC/11i instance. Statspack is showing this wait among the top five (at #5). We are using the "broadcast on commit" scheme as it is recommended by Oracle for 11i instances. Per Metalink, this event is related to the broadcast scheme that we are using. But what does it really mean and at what point it becomes a matter of concern? Any feedback will be appreciated. Thank you=20 Amir=20 ------_=_NextPart_001_01C58A52.4D2E3ACB Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable "wait for scn = from all nodes" wait in RAC
 > roundtrip for the = confirmation of=20 the SCN so that the LGWR can write the redo. We are using three private = gigabit=20 interconnects and in theory there  
enough = bandwidth=20 available to the IC path. 
 
 
 
bandwidth of the interconnect is most likely = not a=20 problem. Latency? Perhaps.
Processor spikes/saturation on certain nodes, = more=20 likely.
 
 
 
 
 
 
Amir


From: = oracle-l-bounce@freelists.org=20 [mailto:oracle-l-bounce@freelists.org] On Behalf Of Cary=20 Millsap
Sent: Friday, July 15, 2005 4:47 PM
To:=20 oracle-l@freelists.org
Subject: RE: "wait for scn from all = nodes"=20 wait in RAC

Amir,

 

Only = you can tell us whether the = issue is=20 of legitimate concern, right? J

 

Is the = event a=20 dominant contributor to the response time of an important business=20 task?

 

Cary=20 Millsap
Hotsos=20 Enterprises, Ltd.
http://www.hotsos.com
Nullius in=20 verba


Visit www.hotsos.com for curriculum and = schedule=20 details...


From:=20 oracle-l-bounce@freelists.org [mailto:oracle-l-bounce@freelists.org] = On Behalf Of Hameed, = Amir
Sent: = Friday, July 15,=20 2005 3:14 PM
To:=20 oracle-l@freelists.org
Subject:
"wait for scn from = all nodes"=20 wait in RAC

 

Does anyone = know what=20 this wait (wait for = scn from all=20 nodes) is about in = RAC. We=20 are currently running a test on a two-node RAC/11i instance. = Statspack is=20 showing this wait among the top five (at #5). We are using the = "broadcast on=20 commit" scheme as it is recommended by Oracle for 11i instances. Per = Metalink, this event is related to the broadcast scheme that we are = using.=20 But what does it really mean and at what point it becomes a matter = of=20 concern? Any feedback will be = appreciated.

Thank=20 you
Amir=20

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