截至本文撰寫為止，RDS Custom for Oracle 不支援多可用區選項，此選項可供 Amazon RDS for Oracle 使用儲存複寫做為 HA 解決方案使用。反之，此模式會使用建立和維護主要資料庫實體複本的待命資料庫來達成 HA。此模式著重於使用 Oracle Data Guard 設定僅供讀取複本，在具有 HA 的 Amazon RDS Custom 上執行 PeopleSoft 應用程式資料庫的步驟。
此模式也會將僅供讀取複本變更為唯讀模式。讓僅供讀取複本處於唯讀模式，可提供額外的優點：
從主要資料庫卸載唯讀工作負載
使用 Oracle Active Data Guard 功能從待命資料庫擷取運作狀態良好的區塊，以啟用損毀區塊的自動修復
使用 Far Sync 功能讓遠端待命資料庫保持同步，而不會產生與長途重做日誌傳輸相關聯的效能額外負荷。
在唯讀模式下使用複本需要 Oracle Active Data Guard 選項，因為這是 Oracle Database Enterprise Edition 的單獨授權功能，因此需要支付額外費用。
依預設，僅供讀取複本會在 MOUNT 模式中建立。若要以唯讀模式開啟它，您首先需要DGMGRL從主要節點或待命節點連線至 來關閉重做套用。
非 CDB
DGMGRL> show database orcl_dDGMGRL> show database orcl_d
Database - orcl_d
Role: PHYSICAL STANDBY
Intended State: APPLY-ONTransport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 0 seconds (computed 1 second ago)
Average Apply Rate: 11.00 KByte/s
Real Time Query: OFFInstance(s):
ORCLDatabase Status:
SUCCESSDGMGRL> edit database orcl_d set state=apply-off;
Succeeded.
DGMGRL> show database orcl_d
Database - orcl_d
Role: PHYSICAL STANDBY
Intended State: APPLY-OFFTransport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 42 seconds (computed 1 second ago)
Average Apply Rate: (unknown)
Real Time Query: OFFInstance(s):
ORCLDatabase Status:
SUCCESSDGMGRL>
CDB
DGMGRL>showconfigurationDGMGRL>showconfigurationConfiguration-rds_dgProtection Mode:MaxAvailabilityMembers:rdscdb_a-Primarydatabaserdscdb_b-PhysicalstandbydatabaseFast-Start Failover:DisabledConfiguration Status:SUCCESS(statusupdated57secondsago)DGMGRL>showdatabaserdscdb_b;Database-rdscdb_bRole:PHYSICALSTANDBYIntended State:APPLY-ONTransport Lag:0seconds(computed1secondago)Apply Lag:0seconds(computed1secondago)Average Apply Rate:2.00KByte/sReal Time Query:OFFInstance(s):RDSCDBDatabase Status:SUCCESSDGMGRL>editdatabaserdscdb_bsetstate=apply-off;Succeeded.DGMGRL>showdatabaserdscdb_b;Database-rdscdb_bRole:PHYSICALSTANDBYIntended State:APPLY-OFFTransport Lag:0seconds(computed1secondago)Apply Lag:0seconds(computed1secondago)Average Apply Rate:(unknown)Real Time Query:OFFInstance(s):RDSCDBDatabase Status:SUCCESS
DBA
以唯讀模式開啟僅供讀取複本執行個體。
使用 TNS 項目連接至待命資料庫，並從主要節點或待命節點連接至待命資料庫，以唯讀模式開啟。
非 CDB
$ sqlplus RDS_DATAGUARD@RDS_CUSTOM_ORCL_D as sysdg
-bash-4.2$ sqlplus RDS_DATAGUARD@RDS_CUSTOM_ORCL_D as sysdg
SQL*Plus: Release19.0.0.0.0- Production on Fri Sep 3023:00:142022
Version 19.10.0.0.0
Copyright (c) 1982, 2020, Oracle. All rights reserved.
Enter password:
Last Successful login time: Fri Sep 30202222:48:27+00:00
Connected to:
Oracle Database 19c Enterprise Edition Release19.0.0.0.0- Production
Version 19.10.0.0.0SQL>select open_mode from v$database;
OPEN_MODE
--------------------
MOUNTED
SQL>alter database open read only;
Database altered.
SQL>select open_mode from v$database;
OPEN_MODE
--------------------
READ ONLYSQL>
CDB
-bash-4.2$ sqlplus C##RDS_DATAGUARD@RDS_CUSTOM_RDSCDB_B as sysdg
SQL*Plus: Release19.0.0.0.0- Production on Wed Jan 1121:14:072023
Version 19.16.0.0.0
Copyright (c) 1982, 2022, Oracle. All rights reserved.
Enter password:
Last Successful login time: Wed Jan 11202321:12:05+00:00
Connected to:
Oracle Database 19c Enterprise Edition Release19.0.0.0.0- Production
Version 19.16.0.0.0SQL>select name,open_mode from v$database;
NAME OPEN_MODE
--------- --------------------
RDSCDB MOUNTED
SQL>alter database open read only;
Database altered.
SQL>select name,open_mode from v$database;
NAME OPEN_MODE
--------- --------------------
RDSCDB READ ONLYSQL>
DBA
啟用重做會套用至僅供讀取複本執行個體。
使用主要節點或待命節點中的 DGMGRL，在僅供讀取複本執行個體上啟用重做。
非 CDB
$dgmgrlRDS_DATAGUARD@RDS_CUSTOM_ORCL_DDGMGRL for Linux:Release19.0.0.0.0-ProductiononFriSep3023:02:162022Version19.10.0.0.0Copyright(c)1982,2019,Oracleand/oritsaffiliates.Allrightsreserved.WelcometoDGMGRL,type"help"forinformation.Password:Connectedto"ORCL_D"ConnectedasSYSDG.DGMGRL>editdatabaseorcl_dsetstate=apply-on;DGMGRL>editdatabaseorcl_dsetstate=apply-on;Succeeded.DGMGRL>showdatabaseorcl_dDatabase-orcl_dRole:PHYSICALSTANDBYIntended State:APPLY-ONTransport Lag:0seconds(computed0secondsago)Apply Lag:0seconds(computed0secondsago)Average Apply Rate:496.00KByte/sReal Time Query:ONInstance(s):ORCLDatabase Status:SUCCESSDGMGRL>
CDB
-bash-4.2$dgmgrlC##RDS_DATAGUARD@RDS_CUSTOM_RDSCDB_B-bash-4.2$dgmgrlC##RDS_DATAGUARD@RDS_CUSTOM_RDSCDB_BDGMGRL for Linux:Release19.0.0.0.0-ProductiononWedJan1121:21:112023Version19.16.0.0.0Copyright(c)1982,2019,Oracleand/oritsaffiliates.Allrightsreserved.WelcometoDGMGRL,type"help"forinformation.Password:Connectedto"RDSCDB_B"ConnectedasSYSDG.DGMGRL>editdatabaserdscdb_bsetstate=apply-on;Succeeded.DGMGRL>showdatabaserdscdb_bDatabase-rdscdb_bRole:PHYSICALSTANDBYIntended State:APPLY-ONTransport Lag:0seconds(computed0secondsago)Apply Lag:0seconds(computed0secondsago)Average Apply Rate:35.00KByte/sReal Time Query:ONInstance(s):RDSCDBDatabase Status:SUCCESSDGMGRL>showdatabaserdscdb_bDatabase-rdscdb_bRole:PHYSICALSTANDBYIntended State:APPLY-ONTransport Lag:0seconds(computed1secondago)Apply Lag:0seconds(computed1secondago)Average Apply Rate:16.00KByte/sReal Time Query:ONInstance(s):RDSCDBDatabase Status:SUCCESSDGMGRL>
DBA
將複本狀態從掛載變更為唯讀，並啟用重做
任務
描述
所需的技能
停止重做會套用至待命資料庫。
依預設，僅供讀取複本會在 MOUNT 模式中建立。若要以唯讀模式開啟它，您首先需要DGMGRL從主要節點或待命節點連線至 來關閉重做套用。
非 CDB
DGMGRL> show database orcl_dDGMGRL> show database orcl_d
Database - orcl_d
Role: PHYSICAL STANDBY
Intended State: APPLY-ONTransport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 0 seconds (computed 1 second ago)
Average Apply Rate: 11.00 KByte/s
Real Time Query: OFFInstance(s):
ORCLDatabase Status:
SUCCESSDGMGRL> edit database orcl_d set state=apply-off;
Succeeded.
DGMGRL> show database orcl_d
Database - orcl_d
Role: PHYSICAL STANDBY
Intended State: APPLY-OFFTransport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 42 seconds (computed 1 second ago)
Average Apply Rate: (unknown)
Real Time Query: OFFInstance(s):
ORCLDatabase Status:
SUCCESSDGMGRL>
CDB
DGMGRL>showconfigurationDGMGRL>showconfigurationConfiguration-rds_dgProtection Mode:MaxAvailabilityMembers:rdscdb_a-Primarydatabaserdscdb_b-PhysicalstandbydatabaseFast-Start Failover:DisabledConfiguration Status:SUCCESS(statusupdated57secondsago)DGMGRL>showdatabaserdscdb_b;Database-rdscdb_bRole:PHYSICALSTANDBYIntended State:APPLY-ONTransport Lag:0seconds(computed1secondago)Apply Lag:0seconds(computed1secondago)Average Apply Rate:2.00KByte/sReal Time Query:OFFInstance(s):RDSCDBDatabase Status:SUCCESSDGMGRL>editdatabaserdscdb_bsetstate=apply-off;Succeeded.DGMGRL>showdatabaserdscdb_b;Database-rdscdb_bRole:PHYSICALSTANDBYIntended State:APPLY-OFFTransport Lag:0seconds(computed1secondago)Apply Lag:0seconds(computed1secondago)Average Apply Rate:(unknown)Real Time Query:OFFInstance(s):RDSCDBDatabase Status:SUCCESS
DBA
以唯讀模式開啟僅供讀取複本執行個體。
使用 TNS 項目連接至待命資料庫，並從主要節點或待命節點連接至待命資料庫，以唯讀模式開啟。
非 CDB
$ sqlplus RDS_DATAGUARD@RDS_CUSTOM_ORCL_D as sysdg
-bash-4.2$ sqlplus RDS_DATAGUARD@RDS_CUSTOM_ORCL_D as sysdg
SQL*Plus: Release19.0.0.0.0- Production on Fri Sep 3023:00:142022
Version 19.10.0.0.0
Copyright (c) 1982, 2020, Oracle. All rights reserved.
Enter password:
Last Successful login time: Fri Sep 30202222:48:27+00:00
Connected to:
Oracle Database 19c Enterprise Edition Release19.0.0.0.0- Production
Version 19.10.0.0.0SQL>select open_mode from v$database;
OPEN_MODE
--------------------
MOUNTED
SQL>alter database open read only;
Database altered.
SQL>select open_mode from v$database;
OPEN_MODE
--------------------
READ ONLYSQL>
CDB
-bash-4.2$ sqlplus C##RDS_DATAGUARD@RDS_CUSTOM_RDSCDB_B as sysdg
SQL*Plus: Release19.0.0.0.0- Production on Wed Jan 1121:14:072023
Version 19.16.0.0.0
Copyright (c) 1982, 2022, Oracle. All rights reserved.
Enter password:
Last Successful login time: Wed Jan 11202321:12:05+00:00
Connected to:
Oracle Database 19c Enterprise Edition Release19.0.0.0.0- Production
Version 19.16.0.0.0SQL>select name,open_mode from v$database;
NAME OPEN_MODE
--------- --------------------
RDSCDB MOUNTED
SQL>alter database open read only;
Database altered.
SQL>select name,open_mode from v$database;
NAME OPEN_MODE
--------- --------------------
RDSCDB READ ONLYSQL>
DBA
啟用重做會套用至僅供讀取複本執行個體。
使用主要節點或待命節點中的 DGMGRL，在僅供讀取複本執行個體上啟用重做。
非 CDB
$dgmgrlRDS_DATAGUARD@RDS_CUSTOM_ORCL_DDGMGRL for Linux:Release19.0.0.0.0-ProductiononFriSep3023:02:162022Version19.10.0.0.0Copyright(c)1982,2019,Oracleand/oritsaffiliates.Allrightsreserved.WelcometoDGMGRL,type"help"forinformation.Password:Connectedto"ORCL_D"ConnectedasSYSDG.DGMGRL>editdatabaseorcl_dsetstate=apply-on;DGMGRL>editdatabaseorcl_dsetstate=apply-on;Succeeded.DGMGRL>showdatabaseorcl_dDatabase-orcl_dRole:PHYSICALSTANDBYIntended State:APPLY-ONTransport Lag:0seconds(computed0secondsago)Apply Lag:0seconds(computed0secondsago)Average Apply Rate:496.00KByte/sReal Time Query:ONInstance(s):ORCLDatabase Status:SUCCESSDGMGRL>
CDB
-bash-4.2$dgmgrlC##RDS_DATAGUARD@RDS_CUSTOM_RDSCDB_B-bash-4.2$dgmgrlC##RDS_DATAGUARD@RDS_CUSTOM_RDSCDB_BDGMGRL for Linux:Release19.0.0.0.0-ProductiononWedJan1121:21:112023Version19.16.0.0.0Copyright(c)1982,2019,Oracleand/oritsaffiliates.Allrightsreserved.WelcometoDGMGRL,type"help"forinformation.Password:Connectedto"RDSCDB_B"ConnectedasSYSDG.DGMGRL>editdatabaserdscdb_bsetstate=apply-on;Succeeded.DGMGRL>showdatabaserdscdb_bDatabase-rdscdb_bRole:PHYSICALSTANDBYIntended State:APPLY-ONTransport Lag:0seconds(computed0secondsago)Apply Lag:0seconds(computed0secondsago)Average Apply Rate:35.00KByte/sReal Time Query:ONInstance(s):RDSCDBDatabase Status:SUCCESSDGMGRL>showdatabaserdscdb_bDatabase-rdscdb_bRole:PHYSICALSTANDBYIntended State:APPLY-ONTransport Lag:0seconds(computed1secondago)Apply Lag:0seconds(computed1secondago)Average Apply Rate:16.00KByte/sReal Time Query:ONInstance(s):RDSCDBDatabase Status:SUCCESSDGMGRL>
