Re: log buffer size and log file syncs

From: saurabh manroy <saurabhmanroy_at_gmail.com>
Date: Mon, 30 Apr 2012 22:17:26 +0200
Message-ID: <CAELkjfV+S8MT4sOJ0NQDG+VZo8Pkvgc4Y+rEAL7-W3aNDNSEUg_at_mail.gmail.com>

Because its 11gR1 and RAC, I wonder how much time is *wait for scn ack* contributing to the log file sync wait? There are few bugs on top of 11gR1 related to broadcast on commit scheme of SCN propagation, that you might want to check:
Bug 8490879 – Long “log file sync” latencies due to broadcast on commit scheme
Bug 7716356 – Long “log file sync” latencies with broadcast on commit scheme in RAC
Bug 7610362 – Long “log file sync” waits in RAC with broadcast on commit in RAC Regards,
Saurabh Manroy

In case you are interested, I have written about log file sync waits in rac here: http://tinyurl.com/89k6jem <http://tinyurl.com/89k6jem>

On Mon, Apr 30, 2012 at 4:56 PM, CRISLER, JON A <JC1706_at_att.com> wrote:

> Interesting thoughts Tanel: in this case of this specific app, the
> majority of the work is made of up small commits to a handful of tables on
> a 6 node RAC cluster. I/O times are generally quite good, and with 32
> cores per node the CPU and load average is very low. Its 11gR1 - I was
> wondering if some of the tweaks to put LGWR at "real time" priority that
> are mentioned for 10g also apply to 11g.
>
>

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Received on Mon Apr 30 2012 - 15:17:26 CDT