10g taf 分享
介绍：
没有配置 TAF的情况下，客户端连接数据库，一个节点宕机，客户端需要重新连接，才能正常连接。
通过 TAF去连接数据库时，当一个节点宕机时，无需重连，会自动切换到另外一个节点，但是前提条件是没有未提交的事务，若有未提交的事务，则会报错 ORA-25405: transaction status unknown，重新连接即可。 三种方法： Client-Side Connect time Failover、 Client-Side TAF、 Service-Side TAF
Service-Side TAF 配置
创建taf服务
srvctl add service -d test -s taf -r "test1,test2" -P BASIC-s 服务名-r 需要创建服务的节点的instance_name-P taf的状态，BASIC为基础状态-d unique name
开启taf服务
srvctl start service -d test -s taf 服务ora.TEST.taf.TEST1.srv
查看状态
srvctl status service -d TEST -s taf
查看taf服务的service_id
SQL> select name,service_id from dba_services where name='taf'; NAME SERVICE_ID-------------------------------------- ----------taf 7
查看taf服务的信息
SQL> select name, failover_method, failover_type, failover_retries,goal, clb_goal,aq_ha_notifications from dba_services where service_id = 7; NAME METHOD TYPE RETRIES GOAL CLB_GOAL AQNOT--------------- ----------- ---------- -------- ---------- -------- -----taf LONG NO
修改参数taf服务的参数
begindbms_service.modify_service(service_name => 'taf', goal => DBMS_SERVICE.goal_throughput, aq_ha_notifications => TRUE, failover_method => DBMS_SERVICE.failover_method_basic, failover_type => DBMS_SERVICE.failover_type_select, failover_retries => 10, failover_delay => 1, clb_goal => DBMS_SERVICE.clb_goal_long);end;/
检查配置情况
再次查看taf服务参数
SQL> select name, failover_method, failover_type, failover_retries,goal, clb_goal,aq_ha_notifications from dba_services where service_id = 7; NAME METHOD TYPE RETRIES GOAL CLB_GOAL AQNOT--------------- ----------- ---------- -------- ---------- -------- -----taf BASIC SELECT 10 THROUGHPUT LONG YES method:basic/nonetype:select/session/nonefailover_retries为failover重试次数goal:
throughput
（数据吞吐量）/
service_time
（服务时间）
/ noneclb_goal:
long
（会将服务均分给每个
rac instance
）
修改tnsname
vi tnsnames.ora TAF = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = rac1-vip.yang.com)(PORT = 1521)) (ADDRESS = (PROTOCOL = TCP)(HOST = rac2-vip.yang.com)(PORT = 1521)) (LOAD_BALANCE = yes) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = taf) ) )
