ORACLE 12CR2 RAC Flex集群与传统标准集群的区别与设置

本文主要讲述安装配置ORACLE 12C R2 RAC时，需要注意的方面：即是Flex集群还是传统的标准集群，默认安装的情况下为传统标准的Flex集群https://www.cndba.cn/Marvinn/article/2760

环境配置

环境 配置

数据库版本 12.2.0.1

系统版本 centos 7

物理内存 4G

CPU 2颗 逻辑4核

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IP配置

# Public Network - (eth0)

172.16.10.116 rac12chub1

172.16.10.142 rac12chub2

# Private Interconnect - (eth1)

192.168.122.222 rac12chub1-priv

192.168.122.238 rac12chub2-priv

# Public Virtual IP (VIP) addresses - (eth0:1)

172.16.10.134 rac12chub1-vip

172.16.10.135 rac12chub2-vip

172.16.10.150 racnode-scanip

标准集群安装方式，这里不再赘述…..跟11GR2 RAC安装基本相同,不同之处在于 MGMT是否跟OCRVOTE放一起以及是否采用Flex 冗余方式 ，另外值得注意的是：

注意: 标准集群即默认为Flex 集群，是因为在选私有IP选定时，默认选择为Private&Asm 导致为Flex ASM产生了Flex 集群，若只选择为Private,则为传统的标准集群，但可升级为Flex 集群(即传统Asm需变更为Flex Asm)，

默认选择Private&Asm安装集群后Mode查看为Flex 集群：

grid@rac12chub2:/home/grid>asmcmd showclustermode

ASM cluster : Flex mode enabled

但是，预检查碰到一个错误, Same core file name pattern，简单说两个节点core 文件值不同，具体原因请查看连接

解决方法：

两个节点执行查看ocre_pattern值

# sysctl kernel.core_pattern

关闭当前被更改core_pattern值节点上的abrtd 服务

# semanage fcontext -a -t public_content_rw_t "/some/dir(/.*)?"

# setsebool -P abrt_anon_write 1

# service abrtd stop

再次查看两个节点ocre_pattern值，检查相同通过

# sysctl kernel.core_pattern

至此…RAC12C 环境是搭建完成…

注意: 标准集群即默认为Flex 集群，是因为在选私有IP选定时，选择为Private&Asm 导致为Flex ASM产生了Flex 集群，若只选择为Private,则为传统的标准集群，但可升级为Flex 集群(即传统Asm需变更为Flex Asm)https://www.cndba.cn/Marvinn/article/2760

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演示过程：

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11G 传统集群RAC: 其中选定为私有Private,并未指定ASM

grid@rac2:/home/grid>oifcfg getif

ens160 172.41.176.0 global public

ens192 10.10.10.0 global cluster_interconnect

grid@rac2:/home/grid>crsctl check crs

CRS-4638: Oracle High Availability Services is online

CRS-4537: Cluster Ready Services is online

CRS-4529: Cluster Synchronization Services is online

CRS-4533: Event Manager is online

12C 传统FlexRAC：其中选定为私有Private&Asm，默认指定ASM为Private,

grid@rac12chub2:/home/grid>oifcfg getif

eth0 172.16.10.0 global public

eth1 192.168.122.0 global cluster_interconnect,asm

grid@rac12chub2:/home/grid>crsctl check crs

CRS-4638: Oracle High Availability Services is online

CRS-4537: Cluster Ready Services is online

CRS-4529: Cluster Synchronization Services is online

CRS-4533: Event Manager is online

grid@rac12chub2:/home/grid>crsctl get node role config -all

Node 'rac12chub1' configured role is 'hub'

Node 'rac12chub2' configured role is 'hub'

总结：

1、若想搭建跟11G RAC相同架构，则私有IP选择需只选择选择Private即可，但角色仍然为Hub.后续可以转换为Flex ASM

2、若想Private 跟 ASM 分开，则需要ASM 需独占IP(两个节点则需再添加两个网卡对应两个IP)，原私有IP只选定为Private,现指定ASM IP则指定为ASM，则输出结果为：ASM独占一行

[root@dg2 ~]# oifcfg getif

eth0 192.168.8.0 global public

eth1 192.168.7.0 global cluster_interconnect

eth2 192.168.7.0 global asm

标准ORACLE Flex ASM架构

传统Flex 集群RAC12C 与传统集群的11G RAC相比，最大不同得是有Hub以及Leaf节点的存在，而Hub节点类似于传统集群节点，但是存在一个最大区别：即传统集群节点11G RAC是ASM实例与数据库实例绑定，ASM实例宕机则直接导致数据库实例无法访问，但是该方式在Flex集群中已将ASM和数据库实例进行了分割,本机ASM实例宕了，其ASM服务飘在其他节点，数据库实例仍然是可以访问的，架构如下：

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Oracle Flex ASM 配置上的 ASM 实例故障:

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1. 登录 RAC 数据库实例 1 (rac1)

[root@rac12chub2 bin]# hostname

rac12chub2

2. 检查 ASM 实例和 RAC 数据库实例的状态

oracle@rac12chub2:/home/oracle>ps -ef | grep pmon

grid 16355 1 0 13:23 ? 00:00:00 asm_pmon_+ASM2

oracle 16641 1 0 13:23 ? 00:00:00 ora_pmon_marvin2

oracle 18325 18277 0 13:28 pts/0 00:00:00 grep --color=auto pmon

3. 从数据库实例 检查 RAC 数据库实例中 ASM 实例的状态

oracle@rac12chub2:/home/oracle>srvctl status asm

ASM is running on rac12chub1,rac12chub2

4. 在ASM实例中检查集群状态

grid@rac12chub2:/home/grid>crsctl check cluster

CRS-4537: Cluster Ready Services is online

CRS-4529: Cluster Synchronization Services is online

CRS-4533: Event Manager is online

5. 用于检查 Oracle Flex ASM 是否启用的命令 (rac12chub2)

grid@rac12chub2:/home/grid>asmcmd showclustermode

ASM cluster : Flex mode enabled

grid@rac12chub2:/home/grid>asmcmd showclusterstate

Normal

6. 用于更改 ASM 基数的命令 (rac12chub2)

grid@rac12chub2:/home/grid>srvctl status asm -detail

ASM is running on rac12chub1,rac12chub2

ASM is enabled.

ASM instance +ASM1 is running on node rac12chub1

Number of connected clients: 2

Client names: marvin1:marvin:rac12ch-cluster rac12chub1:_OCR:rac12ch-cluster

ASM instance +ASM2 is running on node rac12chub2

Number of connected clients: 2

Client names: marvin2:marvin:rac12ch-cluster rac12chub2:_OCR:rac12ch-cluster

查看Asm配置

grid@rac12chub2:/home/grid>srvctl config asm -detail

ASM home:

Password file: +OCR/orapwASM

Backup of Password file:

ASM listener: LISTENER

ASM is enabled.

ASM is individually enabled on nodes:

ASM is individually disabled on nodes:

ASM instance count: 3

Cluster ASM listener: ASMNET1LSNR_ASM

8. 在 RAC 实例 2 (rac12chub) 中关闭 ASM 实例

grid@rac12chub2:/home/grid>srvctl stop asm -node rac12chub2 -stopoption abort -force

grid@rac12chub2:/home/grid>

9. 在 RAC 实例 2 (rac12chub) 中检查 ASM 实例的状态 ，发现ASM实例并未运行在节点2上

grid@rac12chub2:/home/grid>srvctl status asm

ASM is running on rac12chub1

10. 在 RAC 实例 2 (rac12chub) 中检查集群服务的状态，但是集群状态确实正常

grid@rac12chub2:/home/grid>crsctl check cluster

CRS-4537: Cluster Ready Services is online

CRS-4529: Cluster Synchronization Services is online

CRS-4533: Event Manager is online

11. 在 RAC 实例 2 (rac12chub) 中检查 ASM 和 RAC 数据库的状态

grid@rac12chub2:/home/grid>ps -ef | grep pmon

oracle 16641 1 0 13:23 ? 00:00:00 ora_pmon_marvin2

grid 20676 18559 0 13:35 pts/0 00:00:00 grep --color=auto pmon

注：在这里，数据库实例与特定节点中运行的特定 ASM 实例关联。如果因为某种原因，ASM 实例无法启动/服务关闭(当前服务关闭)，数据库实例仍然可以启动，因为数据库实例将查找同一集群中运行的其他 ASM 实例。上图已描绘了 Flex ASM 的高可用特性。

12. 在 RAC 数据库实例 2 (rac12chub) 中检查没有 ASM 实例的正在运行的 RAC 数据库实例的状态

oracle@rac12chub2:/home/oracle>. oraenv

ORACLE_SID = [marvin2] ?

ORACLE_HOME = [/home/oracle] ?

ORACLE_BASE environment variable is not being set since this

information is not available for the current user ID oracle.

You can set ORACLE_BASE manually if it is required.

Resetting ORACLE_BASE to its previous value or ORACLE_HOME

The Oracle base remains unchanged with value /u01/oracle

13. 从RAC 数据库实例 2 (rac12chub) 登录数据库实例

oracle@rac12chub2:/home/oracle>sqlplus / as sysdba

SQL*Plus: Release 12.2.0.1.0 Production on Wed May 2 13:37:48 2018

Copyright (c) 1982, 2016, Oracle. All rights reserved.

Connected to:

Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production

SQL>

SQL>

SQL> exit

Disconnected from Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production

oracle@rac12chub2:/home/oracle>sqlplus / as sysdba

SQL*Plus: Release 12.2.0.1.0 Production on Wed May 2 13:37:57 2018

Copyright (c) 1982, 2016, Oracle. All rights reserved.

Connected to:

Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production

SQL> select instance_name,instance_number from gv$instance;

INSTANCE_NAME INSTANCE_NUMBER

---------------- ---------------

marvin2 2

marvin1 1

SQL> select instance_name,instance_number from v$instance;

INSTANCE_NAME INSTANCE_NUMBER

---------------- ---------------

marvin2 2

SQL> select instance_name,instance_number from gv$instance;

INSTANCE_NAME INSTANCE_NUMBER

---------------- ---------------

marvin2 2

marvin1 1

14. 查看RAC实例2 GI状态

grid@rac12chub2:/home/grid>crsctl status res -t

1 OFFLINE OFFLINE STABLE

ora.asm

1 ONLINE ONLINE rac12chub1 Started,STABLE

2 OFFLINE OFFLINE Instance Shutdown,ST

ABLE

3 OFFLINE OFFLINE STABLE

ora.cvu

1 ONLINE ONLINE rac12chub1 STABLE

总结：数据库实例使用一个专用 ASM 实例，我们强制该 ASM 实例被停止工作来模拟故障，因此数据库实例重新连接到另一节点，并且数据库仍然可以正常使用(在本示例中为节点 1 (rac12chub1))上的现有 ASM 实例。

15. 重新节点2上ASM服务

grid@rac12chub2:/home/grid>srvctl start asm -node rac12chub2

grid@rac12chub2:/home/grid>crsctl status res -t

---------------------------------------------------

ora.LISTENER_SCAN1.lsnr

1 ONLINE ONLINE rac12chub1 STABLE

ora.MGMTLSNR

1 OFFLINE OFFLINE STABLE

ora.asm

1 ONLINE ONLINE rac12chub1 Started,STABLE

2 ONLINE ONLINE rac12chub2 Started,STABLE

3 OFFLINE OFFLINE STABLE

ora.cvu

1 ONLINE ONLINE rac12chub1 STABLE

grid@rac12chub2:/home/grid>srvctl status asm

ASM is running on rac12chub1,rac12chub2

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