测试场景1（模拟NH SITE故障，OB在NH）【推荐】
--master observer 维护DR SITE ：prdb19 DGMGRL> show observer Configuration - dg_config Primary: orcl2dg Active Target: orcl0dg Observer "prdb19" - Master Host Name: prdb19 Last Ping to Primary: 1 second ago Last Ping to Target: 2 seconds ago Observer "prdg19" - Backup Host Name: prdg19 Last Ping to Primary: 2 seconds ago Last Ping to Target: 3 seconds ago DGMGRL> --主库配置：FastStartFailoverTarget ：orcl0dg 该实例位于：prdg19 DGMGRL> show database verbose orcl2dg Database - orcl2dg Role: PRIMARY Intended State: TRANSPORT-ON Instance(s): orcl2dg Properties: DGConnectIdentifier = 'prdg19/orcl2dg' ObserverConnectIdentifier = '' FastStartFailoverTarget = 'orcl0dg' 设置本地DB --全部配置如下： DGMGRL> SHOW CONFIGURATION lag verbose Configuration - dg_config Protection Mode: MaxPerformance Members: orcl2dg - Primary database orcl0dg - (*) Physical standby database Transport Lag: 0 seconds (computed 1 second ago) Apply Lag: 0 seconds (computed 1 second ago) orcl - Physical standby database Transport Lag: 0 seconds (computed 1 second ago) Apply Lag: 0 seconds (computed 1 second ago) (*) Fast-Start Failover target Properties: FastStartFailoverThreshold = '45' OperationTimeout = '40' TraceLevel = 'SUPPORT' FastStartFailoverLagLimit = '30' CommunicationTimeout = '180' ObserverReconnect = '5' FastStartFailoverAutoReinstate = 'TRUE' FastStartFailoverPmyShutdown = 'TRUE' BystandersFollowRoleChange = 'ALL' ObserverOverride = 'TRUE' ExternalDestination1 = '' ExternalDestination2 = '' PrimaryLostWriteAction = 'CONTINUE' ConfigurationWideServiceName = 'orcl_CFG' Fast-Start Failover: Enabled in Potential Data Loss Mode Lag Limit: 30 seconds Threshold: 45 seconds Active Target: orcl0dg Potential Targets: "orcl0dg" --只有本地DB orcl0dg valid Observers: (*) prdb19 prdg19 Shutdown Primary: TRUE Auto-reinstate: TRUE Observer Reconnect: 5 seconds Observer Override: TRUE Configuration Status: SUCCESS DGMGRL>
站点故障模拟：虚拟机断电，备库和ob同时失去联系！
--主库没有关闭，正常 DGMGRL> show observer Configuration - dg_config Primary: orcl2dg Active Target: orcl0dg Observer "prdg19" - Master Host Name: prdg19 Last Ping to Primary: 1 second ago Last Ping to Target: 3 seconds ago Observer "prdb19" - Backup Host Name: prdb19 Last Ping to Primary: 131 seconds ago Last Ping to Target: 100 seconds ago DGMGRL>
测试场景2：(模拟本地SIT 故障，OB在本地)(主库关闭)【隐患较大】
DGMGRL> SET MASTEROBSERVER to prdb19;
Succeeded.
DGMGRL> show observer
Configuration - dg_config
Primary: orcl2dg
Active Target: orcl0dg
Observer "prdb19" - Master
Host Name: prdb19 --本地OB MASTER
Last Ping to Primary: 0 seconds ago
Last Ping to Target: 0 seconds ago
Observer "prdg19" - Backup
Host Name: prdg19
Last Ping to Primary: 1 second ago
Last Ping to Target: 0 seconds ago
DGMGRL>
DGMGRL> edit database orcl2dg set property FastStartFailoverTarget='orcl';
Error: ORA-16654: fast-start failover is enabled
Failed.
DGMGRL> disable fast_start failover
Disabled.
DGMGRL> edit database orcl2dg set property FastStartFailoverTarget='orcl'; 本地DB
Property "faststartfailovertarget" updated
DGMGRL> enable fast_start failover
Enabled in Potential Data Loss Mode.
DGMGRL>
DGMGRL> SHOW CONFIGURATION lag verbose
Configuration - dg_config
Protection Mode: MaxPerformance
Members:
orcl2dg - Primary database
orcl - (*) Physical standby database
Transport Lag: 0 seconds (computed 0 seconds ago)
Apply Lag: 0 seconds (computed 0 seconds ago)
orcl0dg - Physical standby database
Transport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 0 seconds (computed 1 second ago)
(*) Fast-Start Failover target
Properties:
FastStartFailoverThreshold = '45'
OperationTimeout = '40'
TraceLevel = 'SUPPORT'
FastStartFailoverLagLimit = '30'
CommunicationTimeout = '180'
ObserverReconnect = '5'
FastStartFailoverAutoReinstate = 'TRUE'
FastStartFailoverPmyShutdown = 'TRUE'
BystandersFollowRoleChange = 'ALL'
ObserverOverride = 'TRUE'
ExternalDestination1 = ''
ExternalDestination2 = ''
PrimaryLostWriteAction = 'CONTINUE'
ConfigurationWideServiceName = 'orcl_CFG'
Fast-Start Failover: Enabled in Potential Data Loss Mode
Lag Limit: 30 seconds
Threshold: 45 seconds
Active Target: orcl
Potential Targets: "orcl"
orcl valid
Observers: (*) prdb19
prdg19
Shutdown Primary: TRUE
Auto-reinstate: TRUE
Observer Reconnect: 5 seconds
Observer Override: TRUE
Configuration Status:
SUCCESS
DGMGRL>
模拟办法：见本页面图
主库关闭，
2024-10-17T13:17:24.515534+08:00
Primary has heard from neither observer nor target standby within FastStartFailoverThreshold seconds.
It is likely an automatic failover has already occurred. Primary is shutting down.
2024-10-17T13:17:24.549536+08:00
Errors in file /u01/app/oracle/diag/rdbms/orcl2dg/orcl2dg/trace/orcl2dg_lgwr_4385.trc:
ORA-16830: primary isolated from fast-start failover partners longer than FastStartFailoverThreshold seconds: shutting down
LGWR (ospid: ): terminating the instance due to ORA error
2024-10-17T13:17:24.584808+08:00
System state dump requested by (instance=1, osid=4385 (LGWR)), summary=[abnormal instance termination].
System State dumped to trace file /u01/app/oracle/diag/rdbms/orcl2dg/orcl2dg/trace/orcl2dg_diag_4361.trc
2024-10-17T13:17:25.200753+08:00
Dumping diagnostic data in directory=[cdmp_20241017131724], requested by (instance=1, osid=4385 (LGWR)), summary=[abnormal instance termination].
2024-10-17T13:17:26.368261+08:00
Instance terminated by LGWR, pid = 4385
测试场景3 ： FastStartFailoverTarget，多名称配置，第三站点配置在后面，OB第三站点，虽然达到目的，今天测试和昨天测试现象不一样，建议多次测试
DGMGRL> SET MASTEROBSERVER to prdb19;
Succeeded.
DGMGRL> show observer
Configuration - dg_config
Primary: orcl2dg
Active Target: orcl0dg
Observer "prdb19" - Master
Host Name: prdb19
Last Ping to Primary: 0 seconds ago
Last Ping to Target: 0 seconds ago
Observer "prdg19" - Backup
Host Name: prdg19
Last Ping to Primary: 1 second ago
Last Ping to Target: 0 seconds ago
DGMGRL>
DGMGRL> disable fast_start failover
Disabled.
DGMGRL> edit database orcl2dg set property FastStartFailoverTarget='orcl0dg,orcl';
Property "faststartfailovertarget" updated
DGMGRL> enable fast_start failover
Enabled in Potential Data Loss Mode.
DGMGRL>
DGMGRL> SHOW CONFIGURATION lag verbose
Configuration - dg_config
Protection Mode: MaxPerformance
Members:
orcl2dg - Primary database
orcl0dg - (*) Physical standby database
Transport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 0 seconds (computed 1 second ago)
orcl - Physical standby database
Transport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 0 seconds (computed 1 second ago)
(*) Fast-Start Failover target
Properties:
FastStartFailoverThreshold = '45'
OperationTimeout = '40'
TraceLevel = 'SUPPORT'
FastStartFailoverLagLimit = '30'
CommunicationTimeout = '180'
ObserverReconnect = '5'
FastStartFailoverAutoReinstate = 'TRUE'
FastStartFailoverPmyShutdown = 'TRUE'
BystandersFollowRoleChange = 'ALL'
ObserverOverride = 'TRUE'
ExternalDestination1 = ''
ExternalDestination2 = ''
PrimaryLostWriteAction = 'CONTINUE'
ConfigurationWideServiceName = 'orcl_CFG'
Fast-Start Failover: Enabled in Potential Data Loss Mode
Lag Limit: 30 seconds
Threshold: 45 seconds
Active Target: orcl0dg
Potential Targets: "orcl0dg,orcl"
orcl0dg valid
orcl valid
Observers: (*) prdb19
prdg19
Shutdown Primary: TRUE
Auto-reinstate: TRUE
Observer Reconnect: 5 seconds
Observer Override: TRUE
Configuration Status:
SUCCESS
DGMGRL>
模拟故障方法见图：
主库没有关闭，broker 发生切换，建议多次测试！
Configuration - dg_config
Primary: orcl2dg
Active Target: orcl0dg
Observer "prdg19" - Master
Host Name: prdg19
Last Ping to Primary: 3 seconds ago
Last Ping to Target: 1 second ago
Observer "prdb19" - Backup
Host Name: prdb19
Last Ping to Primary: 145 seconds ago
Last Ping to Target: 114 seconds ago
DGMGRL>
测试场景4 ： FastStartFailoverTarget，多名称配置，第三站点配置在前面，OB第三站点，测试结果和昨天一样，不推荐
DGMGRL> SET MASTEROBSERVER to prdb19;
Succeeded.
DGMGRL> show observer
Configuration - dg_config
Primary: orcl2dg
Active Target: orcl0dg
Observer "prdb19" - Master
Host Name: prdb19
Last Ping to Primary: 0 seconds ago
Last Ping to Target: 0 seconds ago
Observer "prdg19" - Backup
Host Name: prdg19
Last Ping to Primary: 1 second ago
Last Ping to Target: 0 seconds ago
DGMGRL>
DGMGRL> disable fast_start failover
Disabled.
DGMGRL> edit database orcl2dg set property FastStartFailoverTarget='orcl,orcl0dg';
Property "faststartfailovertarget" updated
DGMGRL> enable fast_start failover
Enabled in Potential Data Loss Mode.
DGMGRL>
DGMGRL> SHOW CONFIGURATION lag verbose
Protection Mode: MaxPerformance
Members:
orcl2dg - Primary database
orcl - (*) Physical standby database
Transport Lag: 0 seconds (computed 0 seconds ago)
Apply Lag: 0 seconds (computed 0 seconds ago)
orcl0dg - Physical standby database
Transport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 0 seconds (computed 1 second ago)
(*) Fast-Start Failover target
Properties:
FastStartFailoverThreshold = '45'
OperationTimeout = '40'
TraceLevel = 'SUPPORT'
FastStartFailoverLagLimit = '30'
CommunicationTimeout = '180'
ObserverReconnect = '5'
FastStartFailoverAutoReinstate = 'TRUE'
FastStartFailoverPmyShutdown = 'TRUE'
BystandersFollowRoleChange = 'ALL'
ObserverOverride = 'TRUE'
ExternalDestination1 = ''
ExternalDestination2 = ''
PrimaryLostWriteAction = 'CONTINUE'
ConfigurationWideServiceName = 'orcl_CFG'
Fast-Start Failover: Enabled in Potential Data Loss Mode
Lag Limit: 30 seconds
Threshold: 45 seconds
Active Target: orcl
Potential Targets: "orcl,orcl0dg"
orcl valid
orcl0dg valid
Observers: (*) prdb19
prdg19
Shutdown Primary: TRUE
Auto-reinstate: TRUE
Observer Reconnect: 5 seconds
Observer Override: TRUE
Configuration Status:
SUCCESS
模拟故障方法见图
主库关闭：
2024-10-17T13:37:50.874595+08:00
Primary has heard from neither observer nor target standby within FastStartFailoverThreshold seconds.
It is likely an automatic failover has already occurred. Primary is shutting down.
2024-10-17T13:37:50.910293+08:00
Errors in file /u01/app/oracle/diag/rdbms/orcl2dg/orcl2dg/trace/orcl2dg_lgwr_1607.trc:
ORA-16830: primary isolated from fast-start failover partners longer than FastStartFailoverThreshold seconds: shutting down
LGWR (ospid: ): terminating the instance due to ORA error
2024-10-17T13:37:50.947834+08:00
System state dump requested by (instance=1, osid=1607 (LGWR)), summary=[abnormal instance termination].
System State dumped to trace file /u01/app/oracle/diag/rdbms/orcl2dg/orcl2dg/trace/orcl2dg_diag_1588.trc
2024-10-17T13:37:51.512835+08:00
Dumping diagnostic data in directory=[cdmp_20241017133750], requested by (instance=1, osid=1607 (LGWR)), summary=[abnormal instance termination].
2024-10-17T13:37:52.622822+08:00
Instance terminated by LGWR, pid = 1607
大概80秒
Configuration - dg_config
Primary: orcl2dg
Active Target: orcl
Observer "prdb19" - Master
Host Name: prdb19
Last Ping to Primary: 79 seconds ago
Last Ping to Target: 77 seconds ago
Observer "prdg19" - Backup
Host Name: prdg19
Last Ping to Primary: 2 seconds ago
Last Ping to Target: 78 seconds ago
DGMGRL> /
ORA-03135: connection lost contact
Process ID: 3938
Session ID: 423 Serial number: 56624
Configuration details cannot be determined by DGMGRL
DGMGRL> /
标签：ago,seconds,Ping,Primary,FSFOtest,DGMGRL,orcl2dg From： https://www.cnblogs.com/notonlydba/p/18472043