RE: "wait for scn from all nodes" wait in RAC
- From: "Kevin Closson" <kevinc@xxxxxxxxxxxxx>
- To: <Amir.Hameed@xxxxxxxxx>, <Cary.Millsap@xxxxxxxxxx>, <oracle-l@xxxxxxxxxxxxx>
- Date: Sat, 16 Jul 2005 15:04:13 -0700
> 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
> enough bandwidth available to the IC path.
bandwidth of the interconnect is most likely not a problem. Latency?
Perhaps.
Processor spikes/saturation on certain nodes, more likely.
Amir
________________________________
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Cary Millsap
Sent: Friday, July 15, 2005 4:47 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: RE: "wait for scn from all nodes" wait in RAC
Amir,
Only you can tell us whether the issue is of legitimate
concern, right? :-)
Is the event a dominant contributor to the response time
of an important business task?
Cary Millsap
Hotsos Enterprises, Ltd.
http://www.hotsos.com
Nullius in verba
Visit www.hotsos.com for curriculum and schedule
details...
________________________________
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Hameed, Amir
Sent: Friday, July 15, 2005 3:14 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: "wait for scn from all nodes" wait in RAC
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
Amir
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