Data Guard Broker配置與主備庫切換指南

Data Guard Broker基於分佈式的管理框架，可以用來集中創建,管理,配置和監控oracle data guard; Data Guard Broker的組件：
客戶端：Oracle grid control和命令行工具DGMGRL
服務端：DMON進程和配置文件
DMON進程的作用: 響應用戶的請求，更新broker的配置文件，和data guard配置中的其他服務器通信

Data Guard Broker配置要求：
數據庫版本爲：企業版10G R1以上,可以是單實例或者rac環境；
在主庫和備庫上的COMPATIBLE參數必須設定爲9.2.0或更高；
必須有oracle網絡支持，必須配置LOCAL_LISTENER靜態監聽器註冊(非1521端口必須)；
GLOBAL_DBNAME屬性必須設定爲db_uniquename_DGMGRL.db_domain；
DG_BROKER_START參數要設置爲TRUE；
主庫必須運行在歸檔模式；
使用spfile來保證broker的配置文件和服務器初始化參數文件的一致；
所有的數據庫必須在mount(物理備庫)或者open(主庫和邏輯備庫)狀態；
在rac環境下還需要配置DB_BROKER_CONFIG_FILEn參數，將該參數指定共享存儲上；
rac環境下，需要在OCR中要設定start_options參數爲mount；

srvctl add database -d <db_unique_name> -o <ORACLE_HOME> -s mount
或者
srvctl modify database -d <db_unique_name> -o <ORACLE_HOME> -s mount

data guard broker體系結構示意圖:

配置Data Guard Broker，開始之前應該配置好data guard，並保證日誌同步和應用正常

1：配置listener.ora文件和tnsnames.ora文件，添加GLOBAL_DBNAME參數，重啓監聽器，所有的節點都需要配置

[oracle@orcl ~]$ cat $ORACLE_HOME/network/admin/listener.ora
SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (GLOBAL_DBNAME = physical_DGMGRL.herostart.com)
      (ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1)
      (PROGRAM = extproc)
    )
  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.227.30)(PORT = 1521))
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
    )
  )

[oracle@orcl ~]$ lsnrctl services |grep DGMGRL
Service "physical_DGMGRL.herostart.com" has 1 instance(s).

[oracle@physical ~]$ cat $ORACLE_HOME/network/admin/tnsnames.ora
PRIMARY =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.227.20)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = primary.herostart.com)
    )
  )

PHYSICAL =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.227.30)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = physical.herostart.com)
    )
  )

2：設置DG_BROKER_START參數，所有的節點都需要配置

SQL> show parameter dg_broker_start;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
dg_broker_start                      boolean     FALSE
SQL> !ps -ef |grep dmon
oracle   17111 17094  0 15:59 pts/2    00:00:00 /bin/bash -c ps -ef |grep dmon
oracle   17113 17111  0 15:59 pts/2    00:00:00 grep dmon

SQL> alter system set dg_broker_start=TRUE;
System altered.

SQL> !ps -ef |grep dmon
oracle   17128     1  0 15:59 ?        00:00:00 ora_dmon_orcl
oracle   17129 17094  0 15:59 pts/2    00:00:00 /bin/bash -c ps -ef |grep dmon

3:創建並啓用配置文件

[oracle@primary dbs]$ dgmgrl sys/123456@primary
DGMGRL for Linux: Version 10.2.0.1.0 - Production
Copyright (c) 2000, 2005, Oracle. All rights reserved.
Welcome to DGMGRL, type "help" for information.
Connected.
DGMGRL> show configuration;
Error: ORA-16532: Data Guard broker configuration does not exist

Configuration details cannot be determined by DGMGRL
DGMGRL> create configuration 'DG_YANG' as primary database   is 'primary' connect identifier is primary;
Configuration "DG_YANG" created with primary database "primary"
DGMGRL> show database verbose primary;

Database
  Name:            primary
  Role:            PRIMARY
  Enabled:         NO
  Intended State:  OFFLINE
  Instance(s):
    orcl

  Properties:
    InitialConnectIdentifier        = 'primary'
    LogXptMode                      = 'ASYNC'
    Dependency                      = ''
    DelayMins                       = '0'
    Binding                         = 'OPTIONAL'
    MaxFailure                      = '0'
    MaxConnections                  = '1'
    ReopenSecs                      = '300'
    NetTimeout                      = '180'
    LogShipping                     = 'ON'
    PreferredApplyInstance          = ''
    ApplyInstanceTimeout            = '0'
    ArchiveLagTarget                = '0'
    LogArchiveMaxProcesses          = '2'
    LogArchiveMinSucceedDest        = '1'
    FastStartFailoverTarget         = ''
    StatusReport                    = '(monitor)'
    InconsistentProperties          = '(monitor)'
    InconsistentLogXptProps         = '(monitor)'
    SendQEntries                    = '(monitor)'
    LogXptStatus                    = '(monitor)'
    RecvQEntries                    = '(monitor)'
    HostName                        = 'primary.herostart.com'
    SidName                         = 'orcl'
    LocalListenerAddress            = '(ADDRESS=(PROTOCOL=tcp)(HOST=primary.herostart.com)(PORT=1521))'
    StandbyArchiveLocation          = 'dgsby_primary'
    AlternateLocation               = ''
    LogArchiveTrace                 = '0'
    LogArchiveFormat                = '%t_%s_%r.dbf'
    LatestLog                       = '(monitor)'
    TopWaitEvents                   = '(monitor)'

Current status for "primary":
DISABLED

DGMGRL>  add database 'physical' as connect identifier is physical  maintained as physical;
Database "physical" added
DGMGRL> show database verbose physical;

Database
  Name:            physical
  Role:            PHYSICAL STANDBY
  Enabled:         NO
  Intended State:  OFFLINE
  Instance(s):
    orcl

  Properties:
    InitialConnectIdentifier        = 'physical'
    LogXptMode                      = 'ARCH'
    Dependency                      = ''
    DelayMins                       = '0'
    Binding                         = 'OPTIONAL'
    MaxFailure                      = '0'
    MaxConnections                  = '1'
    ReopenSecs                      = '300'
    NetTimeout                      = '180'
    LogShipping                     = 'ON'
    PreferredApplyInstance          = ''
    ApplyInstanceTimeout            = '0'
    ApplyParallel                   = 'AUTO'
    StandbyFileManagement           = 'AUTO'
    ArchiveLagTarget                = '0'
    LogArchiveMaxProcesses          = '2'
    LogArchiveMinSucceedDest        = '1'
    DbFileNameConvert               = ''
    LogFileNameConvert              = ''
    FastStartFailoverTarget         = ''
    StatusReport                    = '(monitor)'
    InconsistentProperties          = '(monitor)'
    InconsistentLogXptProps         = '(monitor)'
    SendQEntries                    = '(monitor)'
    LogXptStatus                    = '(monitor)'
    RecvQEntries                    = '(monitor)'
    HostName                        = 'physical.herostart.com'
    SidName                         = 'orcl'
    LocalListenerAddress            = '(ADDRESS=(PROTOCOL=tcp)(HOST=physical.herostart.com)(PORT=1521))'
    StandbyArchiveLocation          = '/u01/arch/physical_logs/'
    AlternateLocation               = ''
    LogArchiveTrace                 = '0'
    LogArchiveFormat                = '%t_%s_%r.dbf'
    LatestLog                       = '(monitor)'
    TopWaitEvents                   = '(monitor)'

Current status for "physical":
DISABLED
DGMGRL> enable configuration;
Enabled.

備註：在enbale configration這步有個小插曲，出現了“Failed to connect to remote database primary. Error is ORA-12514”錯誤！
詳細內容請參考：http://www.itpub.net/thread-1500089-1-1.html

enable過程需要點時間，可以在備庫上查看日誌：
[oracle@physical ~]$ tail -f /u01/app/oracle/admin/orcl/bdump/drcorcl.log

DGMGRL> show configuration;

Configuration
  Name:                DG_YANG
  Enabled:             YES
  Protection Mode:     MaxPerformance
  Fast-Start Failover: DISABLED
  Databases:
    primary  - Primary database
    physical - Physical standby database

Current status for "DG_YANG":
SUCCESS

更詳細的資料請參考：http://download.oracle.com/docs/cd/B12037_01/server.101/b10822/cli.htm

4：主備庫切換

SQL> select name,open_mode,database_role,switchover_status from v$database;

NAME      OPEN_MODE  DATABASE_ROLE    SWITCHOVER_STATUS
--------- ---------- ---------------- --------------------
ORCL      READ WRITE PRIMARY          SESSIONS ACTIVE


SQL> select name,open_mode,database_role,switchover_status from v$database;

NAME      OPEN_MODE  DATABASE_ROLE    SWITCHOVER_STATUS
--------- ---------- ---------------- --------------------
ORCL      MOUNTED    PHYSICAL STANDBY NOT ALLOWED

開始切換，中間會提示連接不到數據庫，不知道11g版本會不會這樣
DGMGRL> switchover to physical;
Performing switchover NOW, please wait...
Operation requires shutdown of instance "orcl" on database "primary"
Shutting down instance "orcl"...
ORA-01109: database not open

Database dismounted.
ORACLE instance shut down.
Operation requires shutdown of instance "orcl" on database "physical"
Shutting down instance "orcl"...
ORA-01109: database not open

Database dismounted.
ORACLE instance shut down.
Operation requires startup of instance "orcl" on database "primary"
Starting instance "orcl"...
Unable to connect to database
ORA-12521: TNS:listener does not currently know of instance requested in connect descriptor Failed.
You are no longer connected to ORACLE
Please connect again.
Unable to start instance "orcl"
You must start instance "orcl" manually
Operation requires startup of instance "orcl" on database "physical"
You must start instance "orcl" manually
Switchover succeeded, new primary is "physical"

[oracle@primary dbs]$ sqlplus /nolog
SQL*Plus: Release 10.2.0.1.0 - Production on Thu Oct 13 14:36:08 2011
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
SQL> conn /as sysdba
Connected to an idle instance.
SQL> startup mount
ORACLE instance started.

Total System Global Area  167772160 bytes
Fixed Size                  1218316 bytes
Variable Size              71305460 bytes
Database Buffers           92274688 bytes
Redo Buffers                2973696 bytes
Database mounted.
SQL> alter database recover managed standby database disconnect from session;
Database altered.

SQL> select open_mode,name,database_role,switchover_status from v$database;

OPEN_MODE  NAME      DATABASE_ROLE    SWITCHOVER_STATUS
---------- --------- ---------------- --------------------
MOUNTED    ORCL      PHYSICAL STANDBY NOT ALLOWED



[oracle@physical ~]$ sqlplus /nolog
SQL*Plus: Release 10.2.0.1.0 - Production on Thu Oct 13 14:37:06 2011
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
SQL> conn /as sysdba
Connected to an idle instance.
SQL> startup
ORACLE instance started.

Total System Global Area  167772160 bytes
Fixed Size                  1218316 bytes
Variable Size              62916852 bytes
Database Buffers          100663296 bytes
Redo Buffers                2973696 bytes
Database mounted.
Database opened.
SQL> select open_mode,name,database_role,switchover_status from v$database;

OPEN_MODE  NAME      DATABASE_ROLE    SWITCHOVER_STATUS
---------- --------- ---------------- --------------------
READ WRITE ORCL      PRIMARY          SESSIONS ACTIVE


SQL> archive log list;
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /u01/arch/physical_logs/
Oldest online log sequence     15
Next log sequence to archive   16
Current log sequence           16
SQL> alter system switch logfile;
System altered.

SQL> archive log list;
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /u01/arch/physical_logs/
Oldest online log sequence     15
Next log sequence to archive   17
Current log sequence           17


備庫：
SQL> select first_time,next_time,sequence#,applied from v$archived_log where sequence# >= 15;

FIRST_TIME          NEXT_TIME            SEQUENCE# APP
------------------- ------------------- ---------- ---
2011-10-13:14:33:14 2011-10-13:14:38:16         15 YES
2011-10-13:14:38:16 2011-10-13:14:42:38         16 YES

5：DGMGRL報錯如下

[oracle@physical u01]$ dgmgrl sys/123456@physical
DGMGRL for Linux: Version 10.2.0.1.0 - Production
Copyright (c) 2000, 2005, Oracle. All rights reserved.
Welcome to DGMGRL, type "help" for information.
Connected.
DGMGRL> show configuration;

Configuration
  Name:                DG_YANG
  Enabled:             YES
  Protection Mode:     MaxPerformance
  Fast-Start Failover: DISABLED
  Databases:
    primary  - Physical standby database
    physical - Primary database

Current status for "DG_YANG":
Warning: ORA-16608: one or more databases have warnings

DGMGRL> show database physical statusreport;
STATUS REPORT
       INSTANCE_NAME   SEVERITY ERROR_TEXT

DGMGRL> show database primary statusreport;
STATUS REPORT
       INSTANCE_NAME   SEVERITY ERROR_TEXT
                   *    WARNING ORA-16826: apply service state is inconsistent with the DelayMins property

原因：
Oracle Error :: ORA-16826 apply service state is inconsistent with the DelayMins property

Cause
This warning was caused by one of the following reasons:
- The apply service was started without specifying the real-time apply option or without the NODELAY option when the DelayMins property was set to zero.

- The apply service was started with the real-time apply option or with the NODELAY option when the DelayMins property was set to a value greater than zero.

Action
Reenable the standby database to allow the broker to restart the apply service with the apply options that are consistent with the specified value of the DelayMins property.


DGMGRL> show database primary DelayMins;
  DelayMins = '0'
DGMGRL> edit database primary set property DelayMins=1;
Property "delaymins" updated

DGMGRL> edit database physical set property DelayMins=1;
Property "delaymins" updated

DGMGRL> show configuration;

Configuration
  Name:                DG_YANG
  Enabled:             YES
  Protection Mode:     MaxPerformance
  Fast-Start Failover: DISABLED
  Databases:
    primary  - Physical standby database
    physical - Primary database

Current status for "DG_YANG":
SUCCESS

DGMGRL> show database primary statusreport;
STATUS REPORT
       INSTANCE_NAME   SEVERITY ERROR_TEXT

 2011年11月2日更新，之前提到在switchover中間會提示連不上數據庫，經過排查，發現是tnsnames.ora文件service_name配置不正確導致，參考文檔：

https://forums.oracle.com/forums/thread.jspa?threadID=307281