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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>