[Oracle维护工程师手记系列]Data Guard Broker中改属性是否需要两侧分别执行？

Posted 2020-11-06 健哥的数据花园

Data Guard Broker中改属性是否需要两侧分别执行？

Data Guard Broker有一些属性，可以通过 show configuration 看到。
我有时会想，这些个属性，是否是分别属于primary 和 standby，如果
想要修改，是否需要分别登陆到primary 和 standby ，来分别修改呢？

这也是很多客户经常有的疑问。故此我进行了如下的实验。

先看看primary 端的 属性值：

-bash-4.1$ dgmgrl /
DGMGRL for Linux: Version 12.1.0.2.0 - 64bit Production

Copyright (c) 2000, 2013, Oracle. All rights reserved.

Welcome to DGMGRL, type "help" for information.
Connected as SYSDG.

DGMGRL> show configuration verbose;

Configuration - DRSolution

 Protection Mode: MaxPerformance
 Members:
 orcl12102      - Primary database
   orcl12102_stby - Physical standby database

 Properties:
   FastStartFailoverThreshold      = ‘30‘
   OperationTimeout                = ‘30‘
   TraceLevel                      = ‘USER‘
   FastStartFailoverLagLimit       = ‘30‘
   CommunicationTimeout            = ‘180‘　
   ObserverReconnect               = ‘0‘
   FastStartFailoverAutoReinstate  = ‘TRUE‘
   FastStartFailoverPmyShutdown    = ‘TRUE‘
   BystandersFollowRoleChange      = ‘ALL‘
   ObserverOverride                = ‘FALSE‘
   ExternalDestination1            = ‘‘
   ExternalDestination2            = ‘‘
   PrimaryLostWriteAction          = ‘CONTINUE‘

Fast-Start Failover: DISABLED

Configuration Status:
SUCCESS

DGMGRL>

 

再看Standby 端的属性：

-bash-4.1$ dgmgrl /
DGMGRL for Linux: Version 12.1.0.2.0 - 64bit Production

Copyright (c) 2000, 2013, Oracle. All rights reserved.

Welcome to DGMGRL, type "help" for information.
Connected as SYSDG.

DGMGRL> show configuration verbose;

Configuration - DRSolution

 Protection Mode: MaxPerformance
 Members:
 orcl12102      - Primary database
   orcl12102_stby - Physical standby database

 Properties:
   FastStartFailoverThreshold      = ‘30‘
   OperationTimeout                = ‘30‘
   TraceLevel                      = ‘USER‘
   FastStartFailoverLagLimit       = ‘30‘
   CommunicationTimeout            = ‘180‘
   ObserverReconnect               = ‘0‘
   FastStartFailoverAutoReinstate  = ‘TRUE‘
   FastStartFailoverPmyShutdown    = ‘TRUE‘
   BystandersFollowRoleChange      = ‘ALL‘
   ObserverOverride                = ‘FALSE‘
   ExternalDestination1            = ‘‘
   ExternalDestination2            = ‘‘
   PrimaryLostWriteAction          = ‘CONTINUE‘

Fast-Start Failover: DISABLED

Configuration Status:
SUCCESS

DGMGRL>

从 primary 和 standby 两边看到的属性值都是一样的。所以我有一个猜测，这些属性值是共通的。
下面通过修改 CommunicationTimeout 的值来进行验证：

在primary 端修改：

DGMGRL> EDIT CONFIGURATION SET PROPERTY CommunicationTimeout=120;
Property "communicationtimeout" updated

改完后验证一下：

DGMGRL> show configuration verbose;

Configuration - DRSolution

 Protection Mode: MaxPerformance
 Members:
 orcl12102      - Primary database
   orcl12102_stby - Physical standby database

 Properties:
   FastStartFailoverThreshold      = ‘30‘
   OperationTimeout                = ‘30‘
   TraceLevel                      = ‘USER‘
   FastStartFailoverLagLimit       = ‘30‘
   CommunicationTimeout            = ‘120‘　******
   ObserverReconnect               = ‘0‘
   FastStartFailoverAutoReinstate  = ‘TRUE‘
   FastStartFailoverPmyShutdown    = ‘TRUE‘
   BystandersFollowRoleChange      = ‘ALL‘
   ObserverOverride                = ‘FALSE‘
   ExternalDestination1            = ‘‘
   ExternalDestination2            = ‘‘
   PrimaryLostWriteAction          = ‘CONTINUE‘

Fast-Start Failover: DISABLED

Configuration Status:
SUCCESS

DGMGRL>

那么，在 standby 端，会看到怎样的结果呢？

DGMGRL> show configuration verbose;

Configuration - DRSolution

 Protection Mode: MaxPerformance
 Members:
 orcl12102      - Primary database
   orcl12102_stby - Physical standby database

 Properties:
   FastStartFailoverThreshold      = ‘30‘
   OperationTimeout                = ‘30‘
   TraceLevel                      = ‘USER‘
   FastStartFailoverLagLimit       = ‘30‘
   CommunicationTimeout            = ‘120‘　<<<<<<<<<<<<<  从 standby 端，也可以看到这个值，确实被改变了。
   ObserverReconnect               = ‘0‘
   FastStartFailoverAutoReinstate  = ‘TRUE‘
   FastStartFailoverPmyShutdown    = ‘TRUE‘
   BystandersFollowRoleChange      = ‘ALL‘
   ObserverOverride                = ‘FALSE‘
   ExternalDestination1            = ‘‘
   ExternalDestination2            = ‘‘
   PrimaryLostWriteAction          = ‘CONTINUE‘

Fast-Start Failover: DISABLED

Configuration Status:
SUCCESS

DGMGRL>

事实上，从 standby 端来更改其他的属性值，也是可以的，我们也可以从primary 端，连接到 data guard broker，看到同样的改变。

所以说，Data Guard Broker 搭建完毕后，如果想更改其属性值，无论是从primary 端，还是从standby 端，登陆连接到broker 后，
在哪一端修改都是可以的。