1，Server-Side TAF具有TAF的所有特点
2，Client-Side TAF 是在客户端修改tnsnames.ora 文件来配置的，如果有很多客户端使用这个数据库，那么每次微调整都需要把所有的客户端修改一遍，既低效又容易出错。而Service-Side TAF 通过结合Service，在数据库里保存FAIL_MODE的配置，把所有的TAF配置保存在数据字典中，从而省去了客户端的配置工作，客户端的配置则不需要进行任何改动
从配置参数而言，Service-Side TAF和TAF 相比多了一个Instance Role(实例角色)的概念。 所谓的实例角色，就是当有多个Instance 参与一个Service时，可以配置优先使用哪一个Instance为用户提供服务。用户共有两种可选角色。
PREFERRED:首选实例，会优先选择拥有这个角色的实例提供服务。
AVAILABLE: 后备实例，用户连接会优先连接PREFFERRED的Instance，当PREFERRED的Instance不可用时，才会被转到AVAILBALE的Instance上。
要使用Server-Side TAF必须配置Service。 Service 可以在创建数据库时创建，也可以在创建数据库之后修改，既可以使用dbca 配置向导，也可以用命令行的方式配置。
具体配置步骤
1，首先增加一个service，可以使用dbca或者使用命令行
使用命令行方式
srvctl add service -d hnzz -s STAF -r hnzz1 -a hnzz2 -P basic 为dbname为hnzz的数据库创建一个名称为SerTAF的service，hnzz1为首选实例，hnzz2为后备实例，TAF Policy为basic
srvctl start service -d hnzz -s STAF 启动刚创建的service
2，可以使用下面的命令查看创建的结果
$ srvctl config service -d hnzz -s STAF
SerTAF PREF: hnzz1 AVAIL: hnzz2
3，用service TAF 修改配置，需要用dbms_service.modify_service包。
begin
dbms_service.modify_service(
service_name=>'STAF',
failover_method =>dbms_service.failover_method_basic,
failover_type =>dbms_service.failover_type_select,
failover_retries =>180,
failover_delay=>5);
end;
/
4,确认修改已经生效
select NAME,FAILOVER_METHOD,FAILOVER_TYPE,FAILOVER_DELAY from dba_services where NAME='STAF';
5,数据库启动时，会自动启动所有的Service。有时为了为了维护需要，需要禁用这个特性，在维护完成后再启动这个特性。
srvctl enable service -d hnzz -s STAF
查看监听状态
[oracle@node1 ~]$ lsnrctl status
LSNRCTL for Linux: Version 10.2.0.5.0 - Production on 17-FEB-2014 09:53:35
Copyright (c) 1991, 2010, Oracle. All rights reserved.
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
STATUS of the LISTENER
------------------------
Alias LISTENER_NODE1
Version TNSLSNR for Linux: Version 10.2.0.5.0 - Production
Start Date 17-FEB-2014 08:35:03
Uptime 0 days 1 hr. 18 min. 32 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /oracle/app/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File /oracle/app/product/10.2.0/db_1/network/log/listener_node1.log
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.114.151)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.114.131)(PORT=1521)))
Services Summary...
Service "+ASM" has 1 instance(s).
Instance "+ASM1", status BLOCKED, has 1 handler(s) for this service...
Service "+ASM_XPT" has 1 instance(s).
Instance "+ASM1", status BLOCKED, has 1 handler(s) for this service...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "STAF" has 1 instance(s).
Instance "hnzz2", status READY, has 1 handler(s) for this service...
Service "hnzz" has 1 instance(s).
Instance "hnzz2", status READY, has 1 handler(s) for this service...
Service "hnzzXDB" has 1 instance(s).
Instance "hnzz2", status READY, has 1 handler(s) for this service...
Service "hnzz_XPT" has 1 instance(s).
Instance "hnzz2", status READY, has 1 handler(s) for this service...
The command completed successfully
查看数据库中的service
SQL> show parameter service;
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
service_names string STAF
客户端的tnsnames.ora的配置如下
HNZZ =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.114.151)(PORT = 1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.114.152)(PORT = 1521))
(LOAD_BALANCE = yes)
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = STAF)
)
)
图中的两个是我在关闭实例1之前和之后的链接状态
二，删除service
1，首先停止service
srvctl stop service -d hnzz -s STAF
禁用开机启动
srvctl disable service -d hnzz -s STAF
2,删除服务
srvctl remove service -d hnzz -s STAF
$ srvctl remove service -d hnzz -s STAF
STAF PREF: hnzz1 AVAIL: hnzz2
Service STAF is disabled.
Remove service STAF from the database hnzz? (y/[n]) Y
3,查看数据字典中的信息
select name,failover_method,failover_type,goal,clb_goal from dba_services;
4，从数据字典中删除service
begin
dbms_service.delete_service(service_name=>'STAF');
end;
/
删除名称为SerTAF的服务
