>+-dg`。如需如何使用從 Secrets Manager 擷取的 SSH （安全殼層） 金鑰連線至 RDS Custom 執行個體的詳細資訊，請參閱[使用 SSH 連線至 RDS Custom 資料庫執行個體](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/custom-creating.html#custom-creating.ssh)。
若要透過 Data Guard 命令列 (`dgmgrl`) 存取 Oracle Data Guard 代理程式組態，請使用下列程式碼。
**非 CDB**$ dgmgrl RDS_DATAGUARD@RDS_CUSTOM_ORCL_D
DGMGRL for Linux: Release 19.0.0.0.0 - Production on Fri Sep 30 22:44:49 2022
Version 19.10.0.0.0
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
Welcome to DGMGRL, type "help" for information.
Password:
Connected to "ORCL_D"
Connected as SYSDG.
DGMGRL>
DGMGRL> show database orcl_d
Database - orcl_d
Role: PHYSICAL STANDBY
Intended State: APPLY-ON
Transport Lag: 0 seconds (computed 0 seconds ago)
Apply Lag: 0 seconds (computed 0 seconds ago)
Average Apply Rate: 11.00 KByte/s
Instance(s):
ORCL
SUCCESS
DGMGRL>
**CDB**-bash-4.2$ dgmgrl C##RDS_DATAGUARD@RDS_CUSTOM_RDSCDB_B
DGMGRL for Linux: Release 19.0.0.0.0 - Production on Wed Jan 11 20:24:11 2023
Version 19.16.0.0.0
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
Welcome to DGMGRL, type "help" for information.
Password:
Connected to "RDSCDB_B"
Connected as SYSDG.
DGMGRL>
DGMGRL> show database rdscdb_b
Database - rdscdb_b
Role: PHYSICAL STANDBY
Intended State: APPLY-ON
Transport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 0 seconds (computed 1 second ago)
Average Apply Rate: 2.00 KByte/s
Real Time Query: OFF
Instance(s):
RDSCDB
Database Status:
SUCCESS
DGMGRL>
| DBA |
| 從主節點連線至 DGMGRL 以變更日誌傳輸設定。 | 將日誌傳輸模式變更為 `FastSync`，對應於重做傳輸設定 `SYNC+NOAFFIRM`。為了確保您在角色切換後擁有有效的設定，請同時變更主要資料庫和待命資料庫。
**非 CDB**DGMGRL>
DGMGRL> edit database orcl_d set property logxptmode=fastsync;
Property "logxptmode" updated
DGMGRL> show database orcl_d LogXptMode;
LogXptMode = 'fastsync'
DGMGRL> edit database orcl_a set property logxptmode=fastsync;
Property "logxptmode" updated
DGMGRL> show database orcl_a logxptmode;
LogXptMode = 'fastsync'
DGMGRL>
**CDB**DGMGRL> edit database rdscdb_b set property logxptmode=fastsync;DGMGRL> edit database rdscdb_b set property logxptmode=fastsync;
Property "logxptmode" updated
DGMGRL> show database rdscdb_b LogXptMode;
LogXptMode = 'fastsync'
DGMGRL> edit database rdscdb_a set property logxptmode=fastsync;
Property "logxptmode" updated
DGMGRL> show database rdscdb_a logxptmode;
LogXptMode = 'fastsync'
DGMGRL>
| DBA |
| 將保護模式變更為 MaxAvailability。 | `DGMGRL` 從主節點`MaxAvailability`連線至 ，將保護模式變更為 。
**非 CDB**DGMGRL> edit configuration set protection mode as maxavailability;
Succeeded.
DGMGRL> show configuration;
Configuration - rds_dg
Protection Mode: MaxAvailability
Members:
orcl_a - Primary database
orcl_d - Physical standby database
Fast-Start Failover: Disabled
Configuration Status:
SUCCESS (status updated 38 seconds ago)
DGMGRL>
**CDB**DGMGRL> show configuration
Configuration - rds_dg
Protection Mode: MaxAvailability
Members:
rdscdb_a - Primary database
rdscdb_b - Physical standby database
Fast-Start Failover: Disabled
Configuration Status:
SUCCESS (status updated 57 seconds ago)
DGMGRL>
| DBA |
### 將複本狀態從掛載變更為唯讀，並啟用重做
| 任務 | Description | 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，您必須先`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-ON
Transport 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: OFF
Instance(s):
ORCL
Database Status:
SUCCESS
DGMGRL> edit database orcl_d set state=apply-off;
Succeeded.
DGMGRL> show database orcl_d
Database - orcl_d
Role: PHYSICAL STANDBY
Intended State: APPLY-OFF
Transport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 42 seconds (computed 1 second ago)
Average Apply Rate: (unknown)
Real Time Query: OFF
Instance(s):
ORCL
Database Status:
SUCCESS
DGMGRL>
**CDB**DGMGRL> show configurationDGMGRL> show configuration
Configuration - rds_dg
Protection Mode: MaxAvailability
Members:
rdscdb_a - Primary database
rdscdb_b - Physical standby database
Fast-Start Failover: Disabled
Configuration Status:
SUCCESS (status updated 57 seconds ago)
DGMGRL> show database rdscdb_b;
Database - rdscdb_b
Role: PHYSICAL STANDBY
Intended State: APPLY-ON
Transport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 0 seconds (computed 1 second ago)
Average Apply Rate: 2.00 KByte/s
Real Time Query: OFF
Instance(s):
RDSCDB
Database Status:
SUCCESS
DGMGRL> edit database rdscdb_b set state=apply-off;
Succeeded.
DGMGRL> show database rdscdb_b;
Database - rdscdb_b
Role: PHYSICAL STANDBY
Intended State: APPLY-OFF
Transport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 0 seconds (computed 1 second ago)
Average Apply Rate: (unknown)
Real Time Query: OFF
Instance(s):
RDSCDB
Database 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，以唯讀模式開啟該資料庫。
**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: Release 19.0.0.0.0 - Production on Fri Sep 30 23:00:14 2022
Version 19.10.0.0.0
Copyright (c) 1982, 2020, Oracle. All rights reserved.
Enter password:
Last Successful login time: Fri Sep 30 2022 22:48:27 +00:00
Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.10.0.0.0
SQL> 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 ONLY
SQL>
**CDB**-bash-4.2$ sqlplus C##RDS_DATAGUARD@RDS_CUSTOM_RDSCDB_B as sysdg
SQL*Plus: Release 19.0.0.0.0 - Production on Wed Jan 11 21:14:07 2023
Version 19.16.0.0.0
Copyright (c) 1982, 2022, Oracle. All rights reserved.
Enter password:
Last Successful login time: Wed Jan 11 2023 21:12:05 +00:00
Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.16.0.0.0
SQL> 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 ONLY
SQL>
| DBA |
| 在僅供讀取複本執行個體上啟用重做。 | 使用主要節點或待命節點中的 `DGMGR`L，在僅供讀取複本執行個體上啟用重做。
**非 CDB**$ dgmgrl RDS_DATAGUARD@RDS_CUSTOM_ORCL_D
DGMGRL for Linux: Release 19.0.0.0.0 - Production on Fri Sep 30 23:02:16 2022
Version 19.10.0.0.0
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
Welcome to DGMGRL, type "help" for information.
Password:
Connected to "ORCL_D"
Connected as SYSDG.
DGMGRL>
edit database orcl_d set state=apply-on;
DGMGRL> edit database orcl_d set state=apply-on;
Succeeded.
DGMGRL> show database orcl_d
Database - orcl_d
Role: PHYSICAL STANDBY
Intended State: APPLY-ON
Transport Lag: 0 seconds (computed 0 seconds ago)
Apply Lag: 0 seconds (computed 0 seconds ago)
Average Apply Rate: 496.00 KByte/s
Real Time Query: ON
Instance(s):
ORCL
Database Status:
SUCCESS
DGMGRL>
**CDB**-bash-4.2$ dgmgrl C##RDS_DATAGUARD@RDS_CUSTOM_RDSCDB_B-bash-4.2$ dgmgrl C##RDS_DATAGUARD@RDS_CUSTOM_RDSCDB_B
DGMGRL for Linux: Release 19.0.0.0.0 - Production on Wed Jan 11 21:21:11 2023
Version 19.16.0.0.0
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
Welcome to DGMGRL, type "help" for information.
Password:
Connected to "RDSCDB_B"
Connected as SYSDG.
DGMGRL> edit database rdscdb_b set state=apply-on;
Succeeded.
DGMGRL> show database rdscdb_b
Database - rdscdb_b
Role: PHYSICAL STANDBY
Intended State: APPLY-ON
Transport Lag: 0 seconds (computed 0 seconds ago)
Apply Lag: 0 seconds (computed 0 seconds ago)
Average Apply Rate: 35.00 KByte/s
Real Time Query: ON
Instance(s):
RDSCDB
Database Status:
SUCCESS
DGMGRL> show database rdscdb_b
Database - rdscdb_b
Role: PHYSICAL STANDBY
Intended State: APPLY-ON
Transport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 0 seconds (computed 1 second ago)
Average Apply Rate: 16.00 KByte/s
Real Time Query: ON
Instance(s):
RDSCDB
Database Status:
SUCCESS
DGMGRL>
| DBA |
## 相關資源
+ [將 Amazon RDS 設定為 Oracle PeopleSoft 資料庫](https://d1.awsstatic.com/whitepapers/configuring-amazon-rds-as-peoplesoft-database.pdf) (AWS 白皮書）
+ [Oracle Data Guard Broker 指南 ](https://docs.oracle.com/en/database/oracle/oracle-database/19/dgbkr/index.html)(Oracle 參考文件）
+ [Data Guard 概念和管理 ](https://docs.oracle.com/en/database/oracle/oracle-database/19/sbydb/index.html)(Oracle 參考文件）
## 其他資訊
**選取您的資料庫保護模式**
Oracle Data Guard 提供三種保護模式，根據您的可用性、保護和效能需求來設定 Data Guard 環境。下表摘要說明這三種模式。
|
|
| 保護模式 | 重做傳輸設定 | Description |
| --- |--- |--- |
| ***最大效能*** | `ASYNC` | 對於主要資料庫上發生的交易，重做資料會以非同步方式傳輸並寫入待命資料庫重做日誌。因此，效能影響極小。
`MaxPerformance` 由於非同步日誌運送， 無法提供 RPO=0。 |
| ***最大保護*** | `SYNC+AFFIRM` | 對於主要資料庫上的交易，在確認交易之前，重做資料會同步傳輸並寫入待命資料庫重做磁碟上的日誌。如果待命資料庫無法使用，主要資料庫會自行關閉，以確保交易受到保護。 |
| ***最大可用性*** | `SYNC+AFFIRM` | 這類似於 `MaxProtection` 模式，除非未收到來自待命資料庫的確認。在這種情況下，它會像處於 `MaxPerformance` 模式一樣運作，以保留主要資料庫的可用性，直到能夠將其重做串流再次寫入同步待命資料庫為止。 |
| `SYNC+NOAFFIRM` | 對於主要資料庫上的交易，重做會同步傳輸至待命資料庫，而主要只會等待確認已在待命上收到重做，而不是已寫入待命磁碟。此模式也稱為 `FastSync`，可在發生多個同時故障的特殊情況下，提供可能暴露於資料遺失的效能優勢。 |
RDS Custom for Oracle 中的僅供讀取複本會以最大效能保護模式建立，這也是 Oracle Data Guard 的預設保護模式。最大效能模式可為主要資料庫提供最低的效能影響，這可協助您符合以秒為單位測量的復原點目標 (RPO) 需求。
若要實現零資料遺失 (RPO=0) 目標，您可以自訂 Oracle Data Guard 保護模式為 `MaxAvailability`，並使用 `SYNC+NOAFFIRM`設定進行重做傳輸以獲得更好的效能。由於只有在對應的重做向量成功傳輸到待命資料庫之後，才會確認主要資料庫上的遞交，因此主要執行個體和複本之間的網路延遲對於對遞交敏感的工作負載至關重要。我們建議您為工作負載執行負載測試，以評估在 僅供讀取複本自訂為在 `MaxAvailability` 模式下執行時的效能影響。
與在不同可用區域中部署僅供讀取複本相比，在與主要資料庫相同的可用區域中部署僅供讀取複本可提供較低的網路延遲。不過，在相同可用區域中部署主要和僅供讀取複本可能不符合您的 HA 需求，因為在極少數的可用區域無法使用的情況下，主要執行個體和僅供讀取複本執行個體都會受到影響。