晚上配了一套11.2.0.2 的DataGuard物理备库，准备用DGMGRL做切换测试，结果发现在切换过程中会遇到"Unable to connect to database"的问题，具体日志如下:
DGMGRL> switchover to dgogg
Performing switchover NOW, please wait...
New primary database "dgogg" is opening...
Operation requires shutdown of instance "SBDB" on database "sbdb"
Shutting down instance "SBDB"...
ORACLE instance shut down.
Operation requires startup of instance "SBDB" on database "sbdb"
Starting instance "SBDB"...
Unable to connect to database
ORA-12541: TNS:no listener
Failed.
Warning: You are no longer connected to ORACLE.
Please complete the following steps to finish switchover:
start up instance "SBDB" of database "sbdb"
ORA-12541: TNS:no listener显然是因为DGMGRL使用的连接串ConnectIdentifier存在问题，但是在创建DGMGRL的Configuration之前我已经将SERIVCENAME_DGMGLR形式的静态信息添加到listener.ora文件中了，如:
DGLSN =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = vrh3.oracle.com)(PORT = 1588))
)
SID_LIST_DGLSN =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = DGOGG)
(ORACLE_HOME = /s01/orabase/product/11.2.0/dbhome_1)
(SID_NAME = DGOGG)
)
(SID_DESC =
(GLOBAL_DBNAME = DGOGG_DGB)
(ORACLE_HOME = /s01/orabase/product/11.2.0/dbhome_1)
(SID_NAME = DGOGG)
)
(SID_DESC =
(GLOBAL_DBNAME = DGOGG_DGMGRL)
(ORACLE_HOME = /s01/orabase/product/11.2.0/dbhome_1)
(SID_NAME = DGOGG)
)
)
查了半天最后终于发现时因为监听端口的问题，我创建的LISTENER DGLSN使用1588端口，而dgmgrl中的静态连接串默认使用1521端口，如:
DGMGRL> show database dgogg
Database - dgogg
Role: PRIMARY
Intended State: TRANSPORT-ON
Instance(s):
DGOGG
Database Status:
SUCCESS
DGMGRL> show database verbose dgogg
Database - dgogg
Role: PRIMARY
Intended State: TRANSPORT-ON
Instance(s):
DGOGG
Properties:
DGConnectIdentifier = 'dgogg_dgb'
ObserverConnectIdentifier = ''
LogXptMode = 'sync'
DelayMins = '0'
Binding = 'optional'
MaxFailure = '0'
MaxConnections = '1'
ReopenSecs = '300'
NetTimeout = '30'
RedoCompression = 'DISABLE'
LogShipping = 'ON'
PreferredApplyInstance = ''
ApplyInstanceTimeout = '0'
ApplyParallel = 'AUTO'
StandbyFileManagement = 'MANUAL'
ArchiveLagTarget = '0'
LogArchiveMaxProcesses = '4'
LogArchiveMinSucceedDest = '1'
DbFileNameConvert = ''
LogFileNameConvert = ''
FastStartFailoverTarget = ''
InconsistentProperties = '(monitor)'
InconsistentLogXptProps = '(monitor)'
SendQEntries = '(monitor)'
LogXptStatus = '(monitor)'
RecvQEntries = '(monitor)'
SidName = 'DGOGG'
StaticConnectIdentifier = '(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=vrh3.oracle.com)
(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=DGOGG_DGMGRL)(INSTANCE_NAME=DGOGG)(SERVER=DEDICATED)))'
StandbyArchiveLocation = '/s01/orabase/arch'
AlternateLocation = ''
LogArchiveTrace = '0'
LogArchiveFormat = '%t_%s_%r.dbf'
TopWaitEvents = '(monitor)'
了解到问题所在后就容易解决了，只需要修改Broker中的StaticConnectIdentifier就可以了:
edit database dgogg set property StaticConnectIdentifier='(DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = vrh3.oracle.com)(PORT = 1588)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = DGOGG_DGMGRL)))'; edit database sbdb set property StaticConnectIdentifier='(DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = vrh4.oracle.com)(PORT = 1588))) (CONNECT_DATA = (SERVICE_NAME = SBDB_DGMGRL)))';再次尝试切换Switchover DataGuard，不再需要手动启动standby 实例了:
SUCCESS
本文转自maclean_007 51CTO博客，原文链接:
http://blog.51cto.com/maclean/1278070
