dataguard 切換後更換IP,service_name

本帖最後由 selectshen 於 2014-10-28 16:55 編輯

測試DB資訊:
--DB1
os:rhel5.6 ip:123.0.0.52 oracle version:10.2.0.4 sid:rh10g03 db_role:primary
--DB2
os:rhel5.6 ip:123.0.0.54 oracle version:10.2.0.4 sid:rh10g02 db_role:standby

先做一個簡單的switchover
-----------------DB1
SQL> select switchover_status from v$database;

SWITCHOVER_STATUS
--------------------
SESSIONS ACTIVE  
           
----上條語句的結果如果是to_standby,切換就不需要加with session shutdown
SQL> alter database commit to switchover to physical standby with session shutdown;  


Database altered.    
SQL> shutdown immediate;
ORA-01507: database not mounted


ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area  599785472 bytes
Fixed Size                  2085776 bytes
Variable Size             293604464 bytes
Database Buffers          297795584 bytes
Redo Buffers                6299648 bytes
Database mounted.
SQL> alter database recover managed standby database disconnect from session   ;

Database altered.

---------------DB2
SQL> select switchover_status from v$database;

SWITCHOVER_STATUS
--------------------
TO PRIMARY

SQL> alter database commit to switchover to primary;

Database altered.

SQL> alter database open;

Database altered.

SQL> alter system switch logfile;                                          
System altered.

SQL> /

System altered.
--如果你的沒有出什麼錯的話,應該可以看到,就表示已經switchover成功了.
---------------DB2
SQL> select process,thread#,sequence#,status from v$managed_standby;

PROCESS      THREAD#  SEQUENCE# STATUS
--------- ---------- ---------- ------------
ARCH               1        281 CLOSING
ARCH               1        282 CLOSING
LNS                1        283 WRITING

---------------DB1
SQL> select process,thread#,sequence#,status from v$managed_standby;

PROCESS      THREAD#  SEQUENCE# STATUS
--------- ---------- ---------- ------------
ARCH               0          0 CONNECTED
ARCH               1        280 CLOSING
MRP0               1        283 WAIT_FOR_LOG
RFS                1        283 IDLE
RFS                0          0 IDLE

順便說一下failover,failover時是不用管DB1了,因為假設或事實DB1已經掛了,
只需在DB2上alter database recover managed standby database finish force;應用日誌,
然後alter database commit to switchover to primary;就行了.

    上面的很簡單,但生產環境可能就不只是這樣了.如果我們只是簡單的switchover,客戶端的
tnsnames裡存的可是之前的IP和service_name,此時客戶端就需要修改tnsnames裡對應的IP和
service_name,如果是B/s程式還好,直接的C/S程式每個客戶端都要修,有時甚至已經不現實.
所以常常會在switchover之後,還要修改對應的IP和service_name.最近產生了一個個人覺得比較好
的方案,就是我們只需要修改IP就可以了,不需要修改service_name,而是在建dataguard時就加
一個共有的service_name,客戶端連線都透過這個service_name,而主從之間的傳輸可用原本預設
的service_name(常常就是各自的sid).新加的service_name可以透過靜態註冊或動態註冊都可以.
    這樣可以有效避免,常規方式中,客戶端連線的service_name就是primary預設的service_name,
當switchover後,如果在要在新的primary上能讓使用者連線,就要加這個service_name.但如果加了這個
service_name,原有的主從就會因為名稱的衝突無法傳輸.這時的解決辦法可以是重建standby或是修改
sid等,就比較複雜了.
以下測試修改IP:
--假設客戶端連線的IP:123.0.0.52 service_name:rh10g   這裡的service_name已經是兩邊有加的service_name
透過DB1和DB2在 listener.ora中加入:
(SID_DESC =
     (SID_NAME = rh10g03)
     (ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
     (global_dbname = rh10g)
用於靜態註冊.或是透過在DB1和DB2中執行:
SQL> alter system set service_names=rh10g;
用於動態註冊.
--------------------DB1
--需要先把DB1的IP改為一箇中間IP:123.0.0.55,避免修改IP後衝突
--修改裡面IP對應的主機名
vi /etc/hosts
123.0.0.55      srhel10g03
--修改IP為中間IP123.0.0.55
vi /etc/sysconfig/network-scripts/ifcfg-eth0
--修改tnsnames.ora
RH10G02 =
 (DESCRIPTION =
   (ADDRESS = (PROTOCOL = TCP)(HOST = 123.0.0.52)(PORT = 1521))
   (CONNECT_DATA =
     (SERVER = DEDICATED)
     (SERVICE_NAME = rh10g02)
   )
 )

RH10G03 =
 (DESCRIPTION =
   (ADDRESS = (PROTOCOL = TCP)(HOST = 123.0.0.54)(PORT = 1521))
   (CONNECT_DATA =
     (SERVER = DEDICATED)
     (SERVICE_NAME = rh10g03)
   )
 )

--重啟網路
service network restart
---------------------------DB2
--修改裡面IP對應的主機名
vi /etc/hosts
123.0.0.52      srhel10g02
--修改IP
vi /etc/sysconfig/network-scripts/ifcfg-eth0
--修改tnsnames.ora
RH10G02 =
 (DESCRIPTION =
   (ADDRESS = (PROTOCOL = TCP)(HOST = 123.0.0.52)(PORT = 1521))
   (CONNECT_DATA =
     (SERVER = DEDICATED)
     (SERVICE_NAME = rh10g02)
   )
 )

RH10G03 =
 (DESCRIPTION =
   (ADDRESS = (PROTOCOL = TCP)(HOST = 123.0.0.54)(PORT = 1521))
   (CONNECT_DATA =
     (SERVER = DEDICATED)
     (SERVICE_NAME = rh10g03)
   )
 )

--重啟網路
service network restart
-------------------------DB1
--修改裡面IP對應的主機名
vi /etc/hosts
123.0.0.54     srhel10g03
----修改正確IP 123.0.0.54
vi /etc/sysconfig/network-scripts/ifcfg-eth0
--重啟網路
service network restart
-------------------------DB2
--網路修改完後,在DB2上切幾次日誌檢測是否正常

上面是switchover的方法,如果是failover那就簡單了,直接透過靜態或動態註冊加入原primary的service_name,
然後修改IP就可以了.

--dataguard的幾個引數:
log_archive_config='DG_CONFIG=(orcl01,orcl02)'
log_archive_dest_1='LOCATION=/u09/archivelog/orcl01 VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=orcl01'
LOG_ARCHIVE_DEST_2='SERVICE=orcl02 LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,primary_ROLE) DB_UNIQUE_NAME=orcl02'
LOG_ARCHIVE_DEST_STATE_1=ENABLE
LOG_ARCHIVE_DEST_STATE_2=defer
FAL_SERVER=orcl02
FAL_CLIENT=orcl01
db_file_name_convert='orcl02','orcl01' scope=spfile;
log_file_name_convert='orcl02','orcl01' scope=spfile;
standby_file_management=auto