AW: DB CPU and resmgr.cpu.quantum event in top 10 foreground events
Date: Wed, 28 Oct 2020 12:10:19 +0100 (CET)
Message-ID: <1603883419348.39884.a74d5c1fa72f640f9fd76451457637c51d1486bd_at_spica.telekom.de>
Hi all,
I found the reason for our performance problem: For some reason the cpu_count on the new instance was set to 16 (the old instance used 52). I overlooked this basic parameter at the beginning.
Best regards
Ahmed
-----Original-Nachricht-----
Betreff: DB CPU and resmgr.cpu.quantum event in top 10 foreground events
Datum: 2020-10-27T20:20:04+0100
Von: "ahmed.fikri_at_t-online.de" <ahmed.fikri_at_t-online.de>
An: "list, oracle" <oracle-l_at_freelists.org>
Hi all,
after migrating a database from 11.2.0.4 to 12.1.0.2 we encountered some performance issues.
The AWR report is showing this:
Top 10 Foreground Events by Total Wait Time:
Event Wait Total Wait Time (sec) Wait Avg(ms) % DB time Wait Class DB CPU 201.1K 75.5 resmgr.cpu.quantum 930,919 33.7K 36.22 12.7 Scheduler
I think to explain DB CPU would not be easy, but we have found by investigating other java program on the oracle server (Redhat ) that the ulimit was set to a lower value (1024). I'm not sure if this has to do with DB CPU time.
Furthermore I checked the parameter resource_manager_plan and found following:
in the new instance (12.1.2.1 RAC) the parameter is set to
MIXED_WORKLOAD_PLAN. Here we have performance problems
in the old instance (11.2.0.4 RAC) the parameter is set to null.
(Everything work as expected)
Maybe this could explain the 12.7% DB time for resmgr.cpu.quantum
Has anyone encountered problem using this parameter set to
MIXED_WORKLOAD_PLAN?
Best regards
Ahmed
-- http://www.freelists.org/webpage/oracle-lReceived on Wed Oct 28 2020 - 12:10:19 CET