DGMGRL> show configuration;
Configuration - dg_config
Protection Mode: MaxPerformance
Members:
orcldg - Primary database
orcl - Physical standby database
Warning: ORA-16857: standby disconnected from redo source for longer than specified threshold
Fast-Start Failover: DISABLED
Configuration Status:
WARNING (status updated 41 seconds ago)
DGMGRL> exit
$oerr ora 16857
16857,0000, "standby disconnected from redo source for longer than specified threshold"
// *Cause: The amount of time the standby was disconnected from the
// redo source database exceeded the value specified by the
// 'TransportDisconnectedThreshold' database property. It is caused by
// no network connectivity between the redo source and the standby
// databases.
// *Action: Ensure that there is network connectivity between the redo source
// and standby databases, and the redo source is working properly.
$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;
Configuration - dg_config
Protection Mode: MaxPerformance
Members:
orcldg - Primary database
orcl - Physical standby database
Fast-Start Failover: DISABLED
Configuration Status:
SUCCESS (status updated 20 seconds ago)
DGMGRL> The Data Guard broker also has configurable database properties that can be used to generate warnings when a transport or apply lag exceed a user defined value:
The ApplyLagThreshold configurable database property generates a warning status for a logical or physical standby when the database's apply lag exceeds the value specified by the property. The property value is expressed in seconds. A value of 0 seconds results in no warnings being generated when an apply lag exists. As a best practice, Oracle recommends setting ApplyLagThreshold to at least 15 minutes.
The TransportLagThreshold configurable database property can be used to generate a warning status for a logical, physical, or snapshot standby when the database's transport lag exceeds the value specified by the property. The property value is expressed in seconds. A value of 0 seconds results in no warnings being generated when a transport lag exists. As a best practice, Oracle recommends setting TransportLagThreshold to at least 15 minutes.另外有需要云服务器可以了解下创新互联cdcxhl.cn，海内外云服务器15元起步，三天无理由+7*72小时售后在线，公司持有idc许可证，提供“云服务器、裸金属服务器、高防服务器、香港服务器、美国服务器、虚拟主机、免备案服务器”等云主机租用服务以及企业上云的综合解决方案，具有“安全稳定、简单易用、服务可用性高、性价比高”等特点与优势，专为企业上云打造定制，能够满足用户丰富、多元化的应用场景需求。
