- 最后登录
- 2023-8-16
- 在线时间
- 1686 小时
- 威望
- 2135
- 金钱
- 50532
- 注册时间
- 2011-10-12
- 阅读权限
- 200
- 帖子
- 5207
- 精华
- 39
- 积分
- 2135
- UID
- 2
|
10#
发表于 2012-7-10 13:42:16
Description
Oracle NUMA (Non Uniform Memory Architecture) support can be used with large SMP multiprocessor environments with NUMA hardware. When enabled Oracle NUMA support facilitates efficient use of underlying NUMA hardware and may improve database performance.
Oracle NUMA support needs the right combination of hardware, operating system and Oracle version.
With 10.2.0.4 and 11.1.0.7 patchsets, Oracle NUMA support can be enabled on common Operating Systems like AIX, HP-UX, Solaris, Linux and Windows if the underlying hardware characteristic is NUMA.
When running an Oracle database with NUMA support in a NUMA capable environment, Oracle will by default detect if the hardware and operating system are NUMA capable and enable Oracle NUMA support.
Some OS upgrades/patches may enable NUMA (For example on Linux NUMA is enabled with kernel release 2.6.9-67). Care should be taken before enabling NUMA support or leaving it on by default. Please see below under the âRecommendationâ section. Contact your hardware vendor for recommendation and information on your system and operating system NUMA capabilities
Likelihood of Occurrence
The symptoms described in the following section generally occur when:
Oracle database NUMA support is enabled
Both operating system and hardware are NUMA capable.
And :
Database workload is memory constrained (or apply too much memory pressure on a given NUMA memory pool)
Dynamic reconfiguration events change the characteristics of the hardware or partition (e.g number of CPUs, memory available).
Some issues are OS/hardware specific. See bugs caused by NUMA section below.
Dynamic reconfiguration events removing resources from NUMA system such as an entire cell and all its processors are not supported (Please review Note:761065.1)
Possible Symptoms
The problems manifest usually with crashes with internal errors including:
ORA-4031
ORA-600 with argument KSKRECONFIGNUMA2
ORA-600 with argument KSBASEND_INTERNAL
ORA-600 with argument KSMHEAP_ALLOC1
ORA-27302: FAILURE OCCURRED AT: SSKGXPCRE3
Workaround or Resolution
Recommendation
Customers who have their SLAâs unaffected with NUMA enabled can continue to run with no changes.
It is strongly recommended to customers who want to enable NUMA do sufficient testing before going into production.
Apply all the bug fixes or patchset required for your Oracle database version. Fixes for all known NUMA issues in the Oracle database is available for download. Please review the known bugs section.
To disable NUMA consult the section "Steps to disable NUMA" covering the instructions to disable NUMA at the Oracle database level. To disable NUMA at the operating system or hardware level contact your hardware vendor.
Please review the "Caution" section below when disabling NUMA.
Caution
Disabling or enabling NUMA can change application performance.
It is strongly recommended to evaluate the performance after disabling or before enabling NUMA in a test environment.
Operating system and/or hardware configuration may need to be tuned or reconfigured when disabling Oracle NUMA support. Consult your hardware vendor for more information or recommendation
Steps to disable NUMA
Customers can download and apply patch for Bug 8199533 to disable NUMA support. This is a database patch and should be applied to the Database home. This patch is available for common platforms on 10.2.0.4 and 11.1.0.7 releases.
If you apply patch for Bug 8199533 then Oracle will no longer enabled NUMA support by default even if it detects a NUMA capable environment.
Oracle support does not recommended using init.ora parameter "_enable_NUMA_optimization" to disable NUMA. Customers should apply fix for Patch 8199533 to disable NUMA . The patch is rolling upgradeable.
This patch does not need to be applied to the ASM home. However if the same Oracle home is used for both RDBMS and ASM instances then this patch can be applied to the Oracle home.
To enable NUMA optimization after applying patch 8199533, set init.ora parameter _enable_NUMA_optimization=TRUE
上面的参数禁用了 NUMA , NUMA的介绍可以参考 上面的文档, 不推荐 使用 Linux 6.2 + 10gR2这样的组合, 如果使用的话 本质上我也建议禁用NUMA |
|