RE: High "log buffer space" wait in BATCH Type Transactions
- From: VIVEK_SHARMA <VIVEK_SHARMA@xxxxxxxxxxx>
- To: Asif Momen <asif_oracle@xxxxxxxxx>, "oracle-l@xxxxxxxxxxxxx" <oracle-l@xxxxxxxxxxxxx>
- Date: Sun, 24 Feb 2008 21:33:28 +0530
Thanks Asif for responding & the advice
Redo Logfiles are being MOVED to RAW Devices to handle this wait.
6 Redo Log Groups exist with 2 Members each(Multiplexed) , size 750 MB
Storage Box is a SAN Storage - Hitachi , Storage Box Model - Sun StoreEdge -
9990
OS Block Size 8K
Stripe Unit size 64 K
Total Cache on the storage box – 128 GB
Cache Management Policy - Write Behind
CIO/DIO - am NOT sure if it is used.
Cheers
Vivek
________________________________
From: Asif Momen [asif_oracle@xxxxxxxxx]
Sent: Sunday, February 24, 2008 4:42 PM
To: VIVEK_SHARMA; oracle-l@xxxxxxxxxxxxx
Subject: RE: High "log buffer space" wait in BATCH Type Transactions
Hi Vivek,
"log buffer space" wait event occurs normally when Log Writer is too slow or
when the log buffer is too small.
I think in your case LGWR is slow.
> Currently The Redo logfiles are on Mounted filesystem.
What is the OS block size of this mount point?
Did you enable CIO/DIO on this mount point?
How many redo log members do you have?
Regards
Asif Momen
VIVEK_SHARMA <VIVEK_SHARMA@xxxxxxxxxxx> wrote:
Folks
During a Benchmark Run on Batch Type Transactions on NON-RAC Database using
Dedicated sessions following High "log buffer space" wait is seen.
NOTE - Increasing log_buffer size from 7Mb to 32 Mb only resulted in a further
REDUCED Performance.
Currently The Redo logfiles are on Mounted filesystem.
Qs Will moving the Redo back to RAW Devices also Reduce the "log buffer space"
wait wait for BATCH Runs?
NOTE - Previously, For OLTP type Transactions on the SAME Database, High "log
file sync" wait was also seen with Redo on Mounted filesystem which
disappreared when the Redo were moved to RAW Devices.
Oracle 10.2.0.3
Solaris 10
**************** CAUTION - Disclaimer *****************
This e-mail contains PRIVILEGED AND CONFIDENTIAL INFORMATION intended solely
for the use of the addressee(s). If you are not the intended recipient, please
notify the sender by e-mail and delete the original message. Further, you are
not to copy, disclose, or distribute this e-mail or its contents to any other
person and any such actions are unlawful. This e-mail may contain viruses.
Infosys has taken every reasonable precaution to minimize this risk, but is not
liable for any damage you may sustain as a result of any virus in this e-mail.
You should carry out your own virus checks before opening the e-mail or
attachment. Infosys reserves the right to monitor and review the content of all
messages sent to or from this e-mail address. Messages sent to or from this
e-mail address may be stored on the Infosys e-mail system.
***INFOSYS******** End of Disclaimer ********INFOSYS***
--
//www.freelists.org/webpage/oracle-l
Other related posts:
