Re: high log file sync wait
Date: Wed, 28 Nov 2012 22:12:33 +0100
Message-ID: <CALH8A90ONihAUSGN-qcLGUER1D7Qd55cHpbUoQfrJ=vPxCUWxA_at_mail.gmail.com>
Suya,
I don't see any more details to investigate here. Log File Sync of 40ms is just 'slow' in current environments. This is pure physical write IO - so you must go any way to make your physical write IO faster - OR reduce the number of commits in your application.
I don't see any other path to resolve this issue - maybe others do?
Martin
On Mon, Nov 26, 2012 at 7:36 AM, Suya <suya.huang_at_gmail.com> wrote:
> Hi,
> I have a four-node RAC system, the workload runs against the database waits
> on log file sync heavily, average wait time is 82.41 ms, account for 75% DB
> time. The system CPU resource is rich enough, average 70% idle time.
>
> similar testing was done previously, which has log file sync wait with
> average 40 ms, and because the CPU resource shortage, this time, we added
> two logical CPU to the system. but see that the log file sync wait event
> was even worse.
>
> any ideas on what else I should check in the AWR report?
>
> Thanks!
> Suya
>
>
> --
> http://www.freelists.org/webpage/oracle-l
>
-- http://www.freelists.org/webpage/oracle-lReceived on Wed Nov 28 2012 - 22:12:33 CET