1、环境变量：ORACLE_SID=rac1/2
2、initsid.ora：
db_name=ora92
service_names = ora92
instance_name=rac1/2
global_names=false
db_domain=""
3、listener.ora：
SID_LIST_RAC1 =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = ora92)
(ORACLE_HOME = /oracle/oracle9/app/oracle/product/9.2.0)
(SERVICE_NAME=ora92)(SID_NAME = rac1)
)
)
SID_LIST_RAC2 =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = ora92)
(ORACLE_HOME = /oracle/oracle9/app/oracle/product/9.2.0)
(SERVICE_NAME=ora92)(SID_NAME = rac2)
)
)
RAC1 =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 10.1.3.1)(PORT = 1522))
)
)
)
RAC2 =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 10.1.3.2)(PORT = 1522))
)
)
)
三、TAF的设置
其实TAF设置很简单，在tnsnames.ora中添加failover=on即可，有两种不同的设置方法：
1、公用一个tns name方式：==================================================
myrac =
(description=
(load_balance=on)
(failover=on)
(address= (protocol=tcp)(host=10.1.3.1)(port=1522))
(address= (protocol=tcp)(host=10.1.3.2)(port=1522))
(connect_data= (service_name=ora92)
(failover_mode=(type=select)(method=basic)(retries=20)(delay=20))
)
)
==========================================================================
2、指明instance backup方式：===============================================
rac1 =
(description=
(load_balance=on)
(failover=on)
(address= (protocol=tcp)(host=10.1.3.1)(port=1522))
(connect_data= (service_name=ora92)
(failover_mode=(type=select)(method=basic)
(backup=rac2)(retries=20)(delay=20))
)
)
rac2 =
(description=
(load_balance=on)
(failover=on)
(address= (protocol=tcp)(host=10.1.3.2)(port=1522))
(connect_data= (service_name=ora92)
(failover_mode=(type=select)(method=basic)
(backup=rac1)(retries=20)(delay=20))
)
)
==========================================================================
四、TAF测试方法
一般可以将当前连接的instance down下来，client端将不会断开，并自动切换到backup节点上。相反也会自动切换回来。
当然也有人提出用post_transaction的方式来测试TAF，其实这样有时是得不到预期结果的，原因在于Oracle连接到一个instance上后，此后它会优先尝试对该instance的连接，当你disconnect后，client端一有新的请求就会自动尝试对最近连接的instance进行连接，如果不成功才会尝试对backup instance进行连接。
