1.定义
上一篇介绍的TAF是Client-Side，配置在客户端的tnsname.ora文件，如果有很多客户端，将不利于维护，容易出错，而这里介绍的Server-Side TAF结合Service，把所有的TAF配置都保存在数据字典中，这样客户端就无须再做配置了。
2.Service
1）创建一个新的service：
srvctl add service -d O01RCD0 -s taf_test -r O01RCD0A -a O01RCD0B  -P basic
2）查看service是否创建成功：
srvctl config service -d O01RCD0 -s taf_test -a
3）启动该服务：
srvctl start service -d O01RCD0 -s taf_test
4）在数据库上修改Service的TAF配置
begin
 dbms_service.modify_service(
 service_name=>'taf_test',
 failover_method=>dbms_service.failover_method_basic,
 failover_type=>dbms_service.failover_type_select,
 failover_retries=>180,
 failover_delay=>5
 );
 end;
 /

PL/SQL procedure successfully completed.
5) 确认新Service已在数据字典里存在
A105024@O01RCD0>select NAME,FAILOVER_METHOD,FAILOVER_TYPE,FAILOVER_DELAY from dba_services where NAME='taf_test';

NAME                 FAILOVER_METHOD FAILOVER_TYPE   FAILOVER_DELAY
-------------------- --------------- --------------- --------------
taf_test             BASIC           SELECT                       5

3.Listener的配置
我们需要新建一个listener监听该service：
TNS_TAF_TEST =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = drcdd0ra)(PORT = 1521))
    )
  )

SID_LIST_TNS_TAF_TEST =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = taf_test)
      (ORACLE_HOME = /usr/local/oracle/10.2.0-64)
    )
  )


4.客户端配置
客户端配置很简单，只要配置成通过service连接数据库即可。
编辑tnsnames.ora文件如下：
O01RCD0 =
  (DESCRIPTION =
    (failover = on)
        (enable = broken)
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = drcdd0ra)(PORT = 1521))
      (ADDRESS = (PROTOCOL = TCP)(HOST = drcdd0rb)(PORT = 1521))
      (LOAD_BALANCE = yes)
    )
    (CONNECT_DATA =
      (SERVICE_NAME = taf_test)
      )
    )
  )

4.测试
测试环境：两节点的RAC （O01RCD0A，O01RCD0B）
连接数据库，查看连接到哪个实例：
A105024@O01RCD0>select INSTANCE_NAME,status from v$instance;

INSTANCE_NAME    STATUS
---------------- ------------
O01RCD0A         OPEN

3）在服务端kill掉相应的服务进程以拟实例故障
查出用户对应的OS服务进程id：
A105024@O01RCD0>select PID,SPID from v$process where ADDR in (select PADDR from v$session where username='A105024');

       PID SPID
---------- ------------
        43 28563
在OS上杀掉该进程：
kill -9 28563
4）稍等几秒，再次执行语句，发现已经自动切换到了B节点
A105024@O01RCD0>select INSTANCE_NAME,status from v$instance;

A105024@O01RCD0>select INSTANCE_NAME,status from v$instance;

INSTANCE_NAME    STATUS
---------------- ------------
O01RCD0B         OPEN