物理DataGuard客户端无缝切换--客户端TAF 配置

物理 DG 客户端无缝切换 -- 客户端 TAF 配置

    项目客户一直想实现DataGuard的主备切换的自动化，即主库故障后自动切换到备库，并此过程要让应用感知。咨询了DG broker后，考虑到其可用性，易用性，和license问题，放弃了broker。但是物理备库切换到主库还是可以实现对应用透明的。之前我有篇歪门邪道的文章，通过linux系统的IP漂移设置，实现主备切换对应用的透明。对于oracle 11g的dataguard switchover,可以通过创建触发器方式实现自动切换。下面是主要操作步骤：

主库执行：

1. 创建 service

begin

  DBMS_SERVICE.CREATE_SERVICE(service_name        => 'dg_taf_pri',

                              network_name        => 'dg_taf_pri',

                              aq_ha_notifications => TRUE,

                              failover_method     => 'BASIC',

                              failover_type       => 'SELECT',

                              failover_retries    => 30,

                              failover_delay      => 5);

end;

/

2. 创建存储过程，主库启动 service 监听

create or replace procedure dg_taf_proc is                   

    v_role VARCHAR(30);                             

  begin                                             

    select DATABASE_ROLE into v_role from V$DATABASE;

    if v_role = 'PRIMARY' then                      

      DBMS_SERVICE.START_SERVICE('dg_taf_pri');     

    else                                            

      DBMS_SERVICE.STOP_SERVICE('dg_taf_pri');      

    end if;                                         

  end;                                              

  /  

 

select owner,object_name ,procedure_name from dba_procedures where procedure_name='dg_taf_proc'; --procedure_name 列出 package 中的 procedure 、 function

select owner,object_name ,procedure_name from dba_procedures where object_name='DG_TAF_PROC';

select distinct name,owner  from dba_source where name like 'DG_TAF_PROC%';

 

3. 创建触发器，主备切换时触发

create or replace TRIGGER dg_taf_trg_startup

  after startup or db_role_change on database

begin

  dg_taf_proc;

end;

/

select trigger_name, trigger_name

from dba_triggers where trigger_name = 'DG_TAF_TRG_STARTUP';

 

 4. 客户端配置：

dg_taf =

    (DESCRIPTION =

        (ADDRESS = (PROTOCOL = tcp)(HOST = 12.12.12.123)(PORT = 1521))

        (ADDRESS = (PROTOCOL = tcp)(HOST = 12.12.12.125)(PORT = 1521))

            (LOAD_BALANCE = yes)

                (CONNECT_DATA =

                    (SERVER = DEDICATED)

                    (SERVICE_NAME = dg_taf_pri)

                (FAILOVER_MODE =

                    (TYPE = session)

                    (METHOD = basic)

                    (RETRIES = 180)

                    (DELAY = 5)

               )

        )

)

 

【参考】

【DATAGUARD】物理dg配置客户端无缝切换 (八.3)--客户端TAF 配置

http://blog.itpub.net/26736162/viewspace-1811944/

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转载于:http://blog.itpub.net/16976507/viewspace-2636976/