Oracle Study之--resmgr:cpu quantum等待事件 心已赠人 2022-08-05 02:44 211阅读 0赞 **Oracle Study之--resmgr:cpu quantum等待事件** **在AWR Report中出现“resmgr:cpu quantum”等待事件：** **![Center][]** **“resmgr:cpu quantum”等待事件：** 参考metalink的解决方案，是oracle资源管理方面的问题，原文如下： ## Symptoms ## High waits on event 'resmgr:cpu quantum' might be noticed even when resource manager is disabled. You already have confirmed parameter RESOURCE\_MANAGER\_PLAN is set to null but still noticing the above wait events. Top 5 Timed Foreground Events: > Event Waits Time(s) Avg wait(ms) % DB time Wait Class > ------------------------ ------- -------- ------------ -------------- ---------- ----------- > resmgr:cpu quantum 1,596 346,281 216968 89.19 Scheduler > db file scattered read 171,071 14,778 86 3.81 User I/O > log file sync 28,575 10,810 378 2.78 Commit > db file sequential read 943,457 6,569 7 1.69 User I/O > DB CPU 2,133 0.55 ## Cause ## **This could be due to DEFAULT\_MAINTENANCE\_PLAN. From 11g onwards every weekday window has a pre-defined Resource Plan called DEFAULT\_MAINTENANCE\_PLAN, which will become active once the related window opens. Following entries can also be noted in alert log at the time of issue.** Wed Sep 16 02:00:00 2009 Clearing Resource Manager plan via parameter： Wed Sep 16 22:00:00 2009 Setting Resource Manager plan SCHEDULER\[0x2C55\]:DEFAULT\_MAINTENANCE\_PLAN via scheduler window Setting Resource Manager plan DEFAULT\_MAINTENANCE\_PLAN via parameter Wed Sep 16 22:00:05 2009 Begin automatic SQL Tuning Advisor run for special tuning task "SYS\_AUTO\_SQL\_TUNING\_TASK" ## ## ## Solution ## **To disable the DEFAULT\_MAINTENANCE\_PLAN you can use the below steps as suggested in[Note 786346.1][] 1. Set the current resource manager plan to null (or another plan that is not restrictive):** `alter system set resource_manager_plan='';` 2. Change the active windows to use the null resource manager plan (or other nonrestrictive plan) using:``3. Then, for each window\_name (WINDOW\_NAME from DBA\_SCHEDULER\_WINDOWS), run:`` `execute dbms_scheduler.set_attribute('WEEKNIGHT_WINDOW','RESOURCE_PLAN',''); execute dbms_scheduler.set_attribute('WEEKEND_WINDOW','RESOURCE_PLAN','');` 3. Then, for each window\_name (WINDOW\_NAME from DBA\_SCHEDULER\_WINDOWS), run: execute dbms\_scheduler.set\_attribute('<window name>','RESOURCE\_PLAN',''); `execute dbms_scheduler.set_attribute('<window name>','RESOURCE_PLAN','');` ## ## ## References ## **[NOTE:392037.1][NOTE_392037.1] - Database Hangs. Sessions wait for 'resmgr:cpu quantum' [NOTE:756734.1][NOTE_756734.1] - 11g: Scheduler Maintenance Tasks or Autotasks [NOTE:786346.1][Note 786346.1] - Resource Manager and Sql Tunning Advisory DEFAULT\_MAINTENANCE\_PLAN [NOTE:806893.1][NOTE_806893.1] - Large Waits With The Wait Event "Resmgr:Cpu Quantum" 注意：** **但是很多用户会发现禁用资源计划很多时候没有作用.可以禁用Oracle缺省启用的资源调度,最后通过以下参数设置解决问题: \_resource\_manager\_always\_on = false** [Center]: /images/20220805/8c95138533bb4f8bafaae596381fe719.png [Note 786346.1]: https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&id=786346.1 [NOTE_392037.1]: https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&id=392037.1 [NOTE_756734.1]: https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&id=756734.1 [NOTE_806893.1]: https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&id=806893.1
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