Oracle RAC failover 测试(Server TAF方式)

1、服务器端、客户端的环境
  #服务器端环境，host信息
  oracle@bo2dbp:~> cat /etc/hosts |grep vip
  192.168.7.61   bo2dbp-vip.2gotrade.com    bo2dbp-vip
  192.168.7.62   bo2dbs-vip.2gotrade.com    bo2dbs-vip
  
  #服务器端环境，集群信息
  oracle@bo2dbp:~> ./crs_stat.sh 
   Resource name                                Target     State             
  --------------                                ------     -----             
  ora.GOBO4.GOBO4A.inst                         ONLINE     ONLINE on bo2dbp  
  ora.GOBO4.GOBO4B.inst                         ONLINE     ONLINE on bo2dbs  
  ora.GOBO4.db                                  ONLINE     ONLINE on bo2dbp  
  ora.bo2dbp.ASM1.asm                           ONLINE     ONLINE on bo2dbp  
  ora.bo2dbp.LISTENER_BO2DBP.lsnr               ONLINE     ONLINE on bo2dbp  
  ora.bo2dbp.LISTENER_ORA10G_BO2DBP.lsnr        ONLINE     ONLINE on bo2dbp  
  ora.bo2dbp.gsd                                ONLINE     ONLINE on bo2dbp  
  ora.bo2dbp.ons                                ONLINE     ONLINE on bo2dbp  
  ora.bo2dbp.vip                                ONLINE     ONLINE on bo2dbp  
  ora.bo2dbs.ASM2.asm                           ONLINE     ONLINE on bo2dbs  
  ora.bo2dbs.LISTENER_BO2DBS.lsnr               ONLINE     ONLINE on bo2dbs  
  ora.bo2dbs.LISTENER_ORA10G_BO2DBS.lsnr        ONLINE     ONLINE on bo2dbs  
  ora.bo2dbs.gsd                                ONLINE     ONLINE on bo2dbs  
  ora.bo2dbs.ons                                ONLINE     ONLINE on bo2dbs  
  ora.bo2dbs.vip                                ONLINE     ONLINE on bo2dbs  
  ora.ora10g.db                                 ONLINE     ONLINE on bo2dbp 

  #客户端环境
  robin@SZDB:~> cat /etc/issue
  
  Welcome to SUSE Linux Enterprise Server 10 SP3 (x86_64) - Kernel \r (\l).
  
  robin@SZDB:~> sqlplus -v
  
  SQL*Plus: Release 10.2.0.3.0 - Production
  
  #客户端tnsnames配置
  GOBO4 =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.7.61)(PORT = 1521))
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.7.62)(PORT = 1521))
      (LOAD_BALANCE = yes)
      (CONNECT_DATA =
        (SERVER = DEDICATED)
        (SERVICE_NAME = TAF)  #注意我们客户端的SERVICE_NAME，我们设置为TAF 
      )
    )

2、在服务器端配置service
  配置service有多种方式，如dbca，oem，srvctl命令行。下面直接以命令行方式配置
  关于什么是service以及如何使用srvctl命令行创建service，请参考: http://blog.csdn.net/robinson_0612/article/details/8124232
  oracle@bo2dbp:~> srvctl add service -d GOBO4 -s TAF -r GOBO4A -a GOBO4B -P basic
  oracle@bo2dbp:~> srvctl start service -d GOBO4 -s TAF
  oracle@bo2dbp:~> ./crs_stat.sh | grep TAF
  ora.GOBO4.TAF.GOBO4A.srv                      ONLINE     ONLINE on bo2dbp  
  ora.GOBO4.TAF.cs                              ONLINE     ONLINE on bo2dbp            
  oracle@bo2dbp:~> srvctl config service -d GOBO4 -a
  TAF PREF: GOBO4A AVAIL: GOBO4B TAF: basic
  oracle@bo2dbp:~> export ORACLE_SID=GOBO4A
  oracle@bo2dbp:~> sqlplus / as sysdba
  
  SQL*Plus: Release 10.2.0.3.0 - Production on Mon Dec 17 14:55:02 2012
  
  Copyright (c) 1982, 2006, Oracle.  All Rights Reserved.
  
  Connected to:
  Oracle Database 10g Release 10.2.0.3.0 - 64bit Production
  With the Real Application Clusters option
  
  SQL> show parameter service
  
  NAME                                 TYPE        VALUE
  ------------------------------------ ----------- ------------------------------
  service_names                        string      SYS$SYS.KUPC$S_1_2012102317304
                                                   4.GOBO4, SYS$SYS.KUPC$C_1_2012
                                                   1023173044.GOBO4, GOBO4, TAF
  
  SQL> begin   
    2  dbms_service.modify_service(   
    3  service_name=>'TAF',   
    4  failover_method =>dbms_service.failover_method_basic,   
    5  failover_type =>dbms_service.failover_type_select,   
    6  failover_retries =>180,   
    7  failover_delay=>5);   
    8  end;   
    9  /
  
  PL/SQL procedure successfully completed.
    
  SQL> select name,failover_method,failover_type,goal,clb_goal from dba_services
    2  where name='TAF';
  
  NAME                 FAILOVER_METHOD      FAILOVER_TYPE   GOAL         CLB_G
  -------------------- -------------------- --------------- ------------ -----
  TAF                  BASIC                SELECT                       LONG                                                   
  
  SQL> ho lsnrctl status
    ..........
  Service "TAF" has 1 instance(s).
    Instance "GOBO4A", status READY, has 2 handler(s) for this service...
  The command completed successfully

3、测试服务器端TAF
  robin@SZDB:~> sqlplus fail_over/fail@gobo4
  fail_over@GOBO4> get verify.sql
    1  REM the following query is for TAF connection verification
    2  col sid format 99999
    3  col serial# format 9999999
    4  col failover_type format a13
    5  col failover_method format a15
    6  col failed_over format a11
    7  Prompt
    8  Prompt Failover status for current user
    9  Prompt ============================================
   10  SELECT   sid,
   11   serial#,
   12   failover_type,
   13   failover_method,
   14   failed_over
   15   FROM   v$session
   16   WHERE   username = 'FAIL_OVER';
   17  REM the following query is for load balancing verification
   18  col host_name format a20
   19  Prompt
   20  Prompt Current instance name and host name
   21  Prompt ========================================
   22* SELECT   instance_name,host_name FROM v$instance;
   23  
   
  #下面的连接查询中表明客户端当前连接到了节点bo2dbp，其实例名为GOBO4A 
  fail_over@GOBO4> @verify        
  
  Failover status for current user
  ============================================
  
     SID  SERIAL# FAILOVER_TYPE FAILOVER_METHOD FAILED_OVER
  ------ -------- ------------- --------------- -----------
    1073       48 SELECT        BASIC           NO
  
  
  Current instance name and host name
  ========================================
  
  INSTANCE_NAME    HOST_NAME
  ---------------- --------------------
  GOBO4A           bo2dbp  
  
  #此时停止节点bo2dbp
  oracle@bo2dbp:~> srvctl stop instance -d GOBO4 -i GOBO4A
  #查看停止节点bo2dbp即实例GOBO4A后的结果
  oracle@bo2dbp:~> ./crs_stat.sh |grep inst
  ora.GOBO4.GOBO4A.inst                         OFFLINE    OFFLINE           
  ora.GOBO4.GOBO4B.inst                         ONLINE     ONLINE on bo2dbs  
  
  #此时回到客户端再次执行查询，FAILED_OVER的值已经变成YES，即表明当前的session为failover过来的
  #同时实例名和节点名也发生了变化
  fail_over@GOBO4> set timing on;
  fail_over@GOBO4> @verify
  
  Failover status for current user
  ============================================
  
     SID  SERIAL# FAILOVER_TYPE FAILOVER_METHOD FAILED_OVER
  ------ -------- ------------- --------------- -----------
    1082      396 SELECT        BASIC           YES
  
  Elapsed: 00:00:04.19
  
  Current instance name and host name
  ========================================
  
  INSTANCE_NAME    HOST_NAME
  ---------------- --------------------
  GOBO4B           bo2dbs
  
  Elapsed: 00:00:00.01

4、小结
  a、服务器端的TAF方式的failover通过在服务器端配置service来完成
  b、服务器端的TAF方式与客户端的TAF方式产生同样的效果
  b、一旦在服务端配置了基于服务器端的TAF，客户端再无需通过在客户端添加FAILOVER_MODE项
  c、该方式简化客户端配置，通过集中统一管理service实现failover