Difference in writer response time
From: Pap <oracle.developer35_at_gmail.com>
Date: Thu, 8 Apr 2021 13:35:53 +0530
Message-ID: <CAEjw_fhbnmyKMDCCWKACsmUPy5_ErfkzpgCdHcHM+0AJXEUzvQ_at_mail.gmail.com>
Hello Lister, We have two databases which are the same in all the hardware configurations along with DB parameters and are in sync/replicated using golden gate. And those are treated as primary and DR for us and both are active. But we are seeing differences in behaviour when our application points to primary VS when it points to DR. We are seeing during specific times of the day when our system is at its peak, in one of the database i.e DR the DBWR response times spikes till ~200+ms slowing down the write queries while in another database the dbwr response time stays ~65ms for a similar amount of data and transaction volume. So wanted to understand what can cause such drastic differences? Note- Its version 11.2.0.4 of Oracle.
Date: Thu, 8 Apr 2021 13:35:53 +0530
Message-ID: <CAEjw_fhbnmyKMDCCWKACsmUPy5_ErfkzpgCdHcHM+0AJXEUzvQ_at_mail.gmail.com>
Hello Lister, We have two databases which are the same in all the hardware configurations along with DB parameters and are in sync/replicated using golden gate. And those are treated as primary and DR for us and both are active. But we are seeing differences in behaviour when our application points to primary VS when it points to DR. We are seeing during specific times of the day when our system is at its peak, in one of the database i.e DR the DBWR response times spikes till ~200+ms slowing down the write queries while in another database the dbwr response time stays ~65ms for a similar amount of data and transaction volume. So wanted to understand what can cause such drastic differences? Note- Its version 11.2.0.4 of Oracle.
I tried capturing a few key sections of AWR as during the peak time and put it in the attachment in two different tabs. I am seeing the one having a high DBWR response is doing lesser work as compared to the other one. So wondering if it could be the difference in SAN? but As confirmed by the infra team its solid state disk for both of the databases with no difference in infra level. So wanted to understand , why do we see such differences in both databases then?
Thanks and regards
Pap
-- http://www.freelists.org/webpage/oracle-lReceived on Thu Apr 08 2021 - 10:05:53 CEST
- application/vnd.openxmlformats-officedocument.spreadsheetml.sheet attachment: List_Awr_Compare.xlsx