系统环境：
操作系统：RedHat EL5
Oracle： Oracle 11gR2
系统架构图
如图所示：
主数据库（生产库）： BJDB
备 库 （容灾库）： SHDB
DG的架构模式为Physical DG,数据保护模式为：Max Protection。
1、系统架构
主库：
04:44:13 SYS@ TestDB12>show parameter name
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_name string TestDB12
db_unique_name string bjdb
instance_name string TestDB12
service_names string bjdb
04:46:22 SYS@ TestDB12>select name,dbid,database_role,protection_mode from v$database;
NAME DBID DATABASE_ROLE PROTECTION_MODE
------------------------------ ---------- ---------------- --------------------
TESTDB12 2811829300 PRIMARY MAXIMUM PERFORMANCE
主库归档配置：
log_archive_dest_1 string LOCATION=/dsk4/arch_bj
VALID_FOR=(ALL_LOGFILES,ALL_
ROLES)
DB_UNIQUE_NAME=bjdb
log_archive_dest_2 string SERVICE=shdb ASYNC
VALID_FOR=(ONLINE_LOGFILES,P
RIMARY_ROLE)
DB_UNIQUE_NAME=shdb
备库：
04:44:02 SYS@ shdb>show parameter name
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_name string TestDB12
db_unique_name string shdb
instance_name string shdb
service_names string shdb
05:20:19 SYS@ shdb>select name,dbid,database_role,protection_mode from v$database;
NAME DBID DATABASE_ROLE PROTECTION_MODE
--------- ---------- ---------------- --------------------
TESTDB12 2811829300 PHYSICAL STANDBY MAXIMUM PERFORMANCE
备库归档日志：
log_archive_dest_1 string LOCATION=/dsk4/arch_sh
VALID_FOR=(ALL_LOGFILES,ALL_
ROLES)
DB_UNIQUE_NAME=shdb
log_archive_dest_2 string SERVICE=bjdb ASYNC
VALID_FOR=(ONLINE_LOGFILES,P
RIMARY_ROLE)
DB_UNIQUE_NAME=bjdb
主备库网络配置：
BJDB =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = bjsrv)(PORT = 1521))
)
(CONNECT_DATA = (SERVER = DEDICATED)
(SERVICE_NAME = bjdb)
)
)
SHDB =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = shsrv)(PORT = 1521))
)
(CONNECT_DATA = (SERVER = DEDICATED)
(SERVICE_NAME = shdb)
)
)
2、客户端TAF 配置
1）首先在主库上配置一个TAF的service
此服务在数据库出现故障时会发送通知给客户端，允许查询语句在故障转移发生后继续运行。
04:08:02 SYS@ TestDB12>begin
04:11:00 2 DBMS_SERVICE.CREATE_SERVICE
04:11:00 3 (service_name=> 'dg_sw',
04:11:00 4 network_name => 'dg_sw',
04:11:00 5 aq_ha_notifications =>TRUE,
04:11:00 6 failover_method => 'BASIC',
04:11:00 7 failover_type =>'SELECT',
04:11:00 8 failover_retries => 30,
04:11:00 9 failover_delay => 5);
04:11:00 10 end;
04:11:00 11 /
PL/SQL procedure successfully completed.
Elapsed: 00:00:00.15
2）建立一个存储过程，用于调用service，确保只在主库运行
我们创建一个存储过程来实现此目的，如果当前数据库是主库它就启动此服务，如果是备库就停止。
04:15:42 SYS@ TestDB12>create or replace procedure dg_taf_proc
04:15:43 2 is v_role
04:15:43 3 VARCHAR(30);
if v_role = 'PRIMARY'
begin
select DATABASE_ROLE into v_role from V$DATABASE;
04:15:43 6 if v_role = 'PRIMARY'
04:15:43 7 then
04:15:43 8 DBMS_SERVICE.START_SERVICE('dg_sw');
04:15:43 9 else
04:15:43 10 DBMS_SERVICE.STOP_SERVICE('dg_sw');
04:15:43 11 end if;
04:15:43 12 end;
04:15:43 13 /
Procedure created.
3）创建2个触发器来确保服务可以运行
创建两个触发器，让数据库在启动和角色转换时运行此存储过程。
04:15:44 SYS@ TestDB12>
create or replace TRIGGER
04:17:02 2 dg_taf_trg_startup
after startup on database
04:17:02 4 begin
04:17:02 5 dg_taf_proc;
04:17:02 6 end;
04:17:02 7 /
Trigger created.
Elapsed: 00:00:00.08
用于当数据库open时，如果是主库则执行存储过程。
04:17:03 SYS@ TestDB12>
04:18:19 SYS@ TestDB12>create or replace TRIGGER
04:18:21 2 dg_taf_trg_rolechange
04:18:21 3 after db_role_change on database
04:18:21 4 begin
04:18:21 5 dg_taf_proc;
04:18:21 6 end;
04:18:21 7 /
Trigger created.
当数据库切换后，如果是主库则执行存储过程。
4）客户端tnsnames 配置
DG_SW =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.8.120)(PORT = 1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.8.130)(PORT = 1521))
(LOAD_BALANCE = yes)
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = dg_sw)
(FAILOVER_MODE =
(TYPE = session)
(METHOD = basic)
(RETRIES = 180)
(DELAY = 5)
)
)
)
注：8.120 是主库，8.130 是备库
3、验证客户端的TAF
1）首先在主库上执行该存储过程
04:19:09 SYS@ TestDB12>execute dg_taf_proc;
PL/SQL procedure successfully completed.
Elapsed: 00:00:00.06
04:22:55 SYS@ TestDB12>show parameter name
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_name string TestDB12
db_unique_name string bjdb
instance_name string TestDB12
service_names string dg_sw
注：service_name 变为dg_sw
04:23:01 SYS@ TestDB12> alter system switch logfile;
在主库做日志的切换，将变化应用到备库
2）在备库查询
04:27:30 SYS@ shdb>select trigger_name,trigger_name from dba_triggers
04:28:00 2 where trigger_name like '%DG%';
TRIGGER_NAME TRIGGER_NAME
------------------------------ ------------------------------
DG_TAF_TRG_STARTUP DG_TAF_TRG_STARTUP
DG_TAF_TRG_ROLECHANGE DG_TAF_TRG_ROLECHANGE
3）客户端连接测试
C:\Documents and Settings\tiany>sqlplus sys/oracle@dg_sw as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on 星期三 4月 23 16:35:28 2014
Copyright (c) 1982, 2010, Oracle. All rights reserved.
连接到:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP, Data Mining,
Oracle Database Vault and Real Application Testing options
SQL>
此时应连接到主库！
4、主备库切换后的TAF测试
1）主备库切换
主库切换后：
04:41:31 SYS@ TestDB12>select database_role ,switchover_status from v$database;
DATABASE_ROLE SWITCHOVER_STATUS
---------------- --------------------
PHYSICAL STANDBY RECOVERY NEEDED
备库切换后：
04:31:17 SYS@ shdb>select database_role ,switchover_status from v$database;
DATABASE_ROLE SWITCHOVER_STATUS
---------------- --------------------
PRIMARY NOT ALLOWED
Elapsed: 00:00:00.02
2）客户端连接测试
C:\Documents and Settings\tiany>sqlplus sys/oracle@dg_sw as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on 星期三 4月 23 16:43:49 2014
Copyright (c) 1982, 2010, Oracle. All rights reserved.
连接到:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP, Data Mining,
Oracle Database Vault and Real Application Testing options
SQL> show parameter name
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_name string TestDB12
db_unique_name string shdb
instance_name string shdb
service_names string dg_sw
切换后，在备库上存储过程启动了TAF的service ，客户端再连接时，自动连接到了当前的主库（原备库）。
@至此，在DG环境下客户端的TAF配置基本完成。
