What's the problem?
Via awr report, below top event was found. How to solve Top 1 event: resmgr:cpu quantum ?
Top 5 Timed Foreground Events
| Event | Waits | Time(s) | Avg wait (ms) | % DB time | Wait Class |
|---|---|---|---|---|---|
| resmgr:cpu quantum | 150,482 | 109,717 | 729 | 26.75 | Scheduler |
| DB CPU | 40,945 | 9.98 | |||
| latch: cache buffers chains | 192,607 | 35,567 | 185 | 8.67 | Concurrency |
| log file sync | 75,662 | 13,579 | 179 | 3.31 | Commit |
| db file sequential read | 128,196 | 3,371 | 26 | 0.82 | User I/O |
Host CPU (CPUs: 2 Cores: Sockets: )
What's the root cause?
ResourceManager:
Subject | 10g | 11g |
Maintenance Window | 2 windows, WEEK and WEEKEND | Each day has its own window |
Resource manager | Not enabled per default | Default resource plan specified |
SqlTunning Advisory:
Oracle Database 11g, bydefault, the Automatic Tunning Optimizer runs regularly during the Oraclescheduler Maintenance window, as the new automated maintenance task called theSQL Tunning Advisory task.
So this is a default behavior in Oracle 11g.
1].To disable the resource manager you can use the below steps.
++ set thecurrent resource manager plan to null (or another plan that is not restrictive):
alter system set resource_manager_plan='' scope=both
++ change the active windows to use the null resource manager plan (or othernonrestrictive plan) using:
execute dbms_scheduler.set_attribute('WEEKNIGHT_WINDOW','RESOURCE_PLAN',''); and
execute dbms_scheduler.set_attribute('WEEKEND_WINDOW','RESOURCE_PLAN','');
For 11g,you need to change those too:
executedbms_scheduler.set_attribute('SATURDAY_WINDOW','RESOURCE_PLAN','');
execute dbms_scheduler.set_attribute('SUNDAY_WINDOW','RESOURCE_PLAN','');
execute dbms_scheduler.set_attribute('MONDAY_WINDOW','RESOURCE_PLAN','');
execute dbms_scheduler.set_attribute('TUESDAY_WINDOW','RESOURCE_PLAN','');
execute dbms_scheduler.set_attribute('WEDNESDAY_WINDOW','RESOURCE_PLAN','');
execute dbms_scheduler.set_attribute('THURSDAY_WINDOW','RESOURCE_PLAN','');
execute dbms_scheduler.set_attribute('FRIDAY_WINDOW','RESOURCE_PLAN','');
++ Then, for each window_name (WINDOW_NAME from DBA_SCHEDULER_WINDOWS),run:
SQL> execute dbms_scheduler.set_attribute('<windowname>','RESOURCE_PLAN','');
補充如何獲得awr report：
pwd
/home/oracle
export ORACLE_SID=xx
sqlplus / as sysdba
SQL> @?/rdbms/admin/awrrpt.sql
Current Instance
~~~~~~~~~~~~~~~~
DB Id DB Name Inst Num Instance
----------- ------------ -------- ------------
165375853 WAPI2 1 wapi2
Specify the Report Type
~~~~~~~~~~~~~~~~~~~~~~~
Would you like an HTML report, or a plain text report?
Enter 'html' for an HTML report, or 'text' for plain text
Defaults to 'html'
Enter value for report_type: html
Type Specified: html
Instances in this Workload Repository schema
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
DB Id Inst Num DB Name Instance Host
------------ -------- ------------ ------------ ------------
* 165375853 1 WAPI2 wapi2 oradbhasvr00
1
Using 165375853 for database Id
Using 1 for instance number
Specify the number of days of snapshots to choose from
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Entering the number of days (n) will result in the most recent
(n) days of snapshots being listed. Pressing <return> without
specifying a number lists all completed snapshots.
Enter value for num_days: 1
Listing the last day's Completed Snapshots
Snap
Instance DB Name Snap Id Snap Started Level
------------ ------------ --------- ------------------ -----
wapi2 WAPI2 13418 02 Aug 2013 00:00 1
13419 02 Aug 2013 01:00 1
13420 02 Aug 2013 02:00 1
Specify the Begin and End Snapshot Ids
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Enter value for begin_snap: 13418
Begin Snapshot Id specified: 13418
Enter value for end_snap: 13420
End Snapshot Id specified: 13420
Specify the Report Name
~~~~~~~~~~~~~~~~~~~~~~~
The default report file name is awrrpt_1_13418_13420.html. To use this name,
press <return> to continue, otherwise enter an alternative.
Enter value for report_name: wapi2.html
....
然後在當前目錄下獲得圖章診斷報告wapi2.html。