>+-dg`。
**其他服務**
+ [Oracle Data Guard](https://docs.oracle.com/en/database/oracle/oracle-database/21/sbydb/introduction-to-oracle-data-guard-concepts.html#GUID-5E73667D-4A56-445E-911F-1E99092DD8D7) 可協助您建立、維護、管理和監控待命資料庫。此模式使用 Oracle Data Guard 最高效能來轉換角色 ([Oracle Data Guard 切換](https://docs.oracle.com/database/121/DGBKR/sofo.htm#DGBKR330))。
## 最佳實務
對於您的生產部署，我們建議您在第三個可用區域中啟動觀察器執行個體，與主要節點和僅供讀取複本節點分開。
## 史詩
### 啟動角色轉換
| 任務 | Description | 所需的技能 |
| --- | --- | --- |
| 暫停主要和複本的資料庫自動化。 | 雖然 RDS Custom 自動化架構不會干擾角色轉換程序，但最好在 Oracle Data Guard 切換期間暫停自動化。若要暫停和繼續 RDS Custom 資料庫自動化，請遵循[暫停和繼續 RDS Custom 自動化](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/custom-managing.html#custom-managing.pausing)中的指示。 | 雲端管理員，DBA |
| 檢查 Oracle Data Guard 狀態。 | 若要檢查 Oracle Data Guard 狀態，請登入主要資料庫。此模式包含使用多租戶容器資料庫 (CDB) 或非 CDB 執行個體的程式碼。**非 CDB**-bash-4.2$ dgmgrl RDS_DATAGUARD@RDS_CUSTOM_ORCL_A
DGMGRL for Linux: Release 19.0.0.0.0 - Production on Mon Nov 28 20:55:50 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_A"
Connected as SYSDG.
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 59 seconds ago)
DGMGRL>
**CDB**CDB-bash-4.2$ dgmgrl C##RDS_DATAGUARD@RDS_CUSTOM_RDSCDB_A
DGMGRL for Linux: Release 19.0.0.0.0 - Production on Wed Jan 18 06:13:07 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_A"
Connected as SYSDG.
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 52 seconds ago)
DGMGRL>
| DBA |
| 驗證執行個體角色。 | 開啟 AWS 管理主控台，然後導覽至 Amazon RDS 主控台。在資料庫的**複寫**區段的**連線與安全**索引標籤上，驗證主要和複本的執行個體角色。主要角色應與 Oracle Data Guard 主要資料庫相符，而複本角色應與 Oracle Data Guard 實體待命資料庫相符。 | 雲端管理員，DBA |
| 執行切換。 | 若要執行切換，`DGMGRL`請從主節點連線至 。**非 CDB**DGMGRL> switchover to orcl_d;
Performing switchover NOW, please wait...
Operation requires a connection to database "orcl_d"
Connecting ...
Connected to "ORCL_D"
Connected as SYSDG.
New primary database "orcl_d" is opening...
Operation requires start up of instance "ORCL" on database "orcl_a"
Starting instance "ORCL"...
Connected to an idle instance.
ORACLE instance started.
Connected to "ORCL_A"
Database mounted.
Database opened.
Connected to "ORCL_A"
Switchover succeeded, new primary is "orcl_d"
DGMGRL>
**CDB**DGMGRL> switchover to rdscdb_b
Performing switchover NOW, please wait...
New primary database "rdscdb_b" is opening...
Operation requires start up of instance "RDSCDB" on database "rdscdb_a"
Starting instance "RDSCDB"...
Connected to an idle instance.
ORACLE instance started.
Connected to "RDSCDB_A"
Database mounted.
Database opened.
Connected to "RDSCDB_A"
Switchover succeeded, new primary is "rdscdb_b"
| DBA |
| 驗證 Oracle Data Guard 連線。 | 切換後，驗證從主節點到 的 Oracle Data Guard 連線`DGMGRL`。**非 CDB**DGMGRL> show configuration;
Configuration - rds_dg
Protection Mode: MaxAvailability
Members:
orcl_d - Primary database
orcl_a - Physical standby database
Fast-Start Failover: Disabled
Configuration Status:
SUCCESS (status updated 60 seconds ago)
DGMGRL>
DGMGRL> show configuration lag;
Configuration - rds_dg
Protection Mode: MaxAvailability
Members:
orcl_d - Primary database
orcl_a - Physical standby database
Transport Lag: 0 seconds (computed 0 seconds ago)
Apply Lag: 0 seconds (computed 0 seconds ago)
Fast-Start Failover: Disabled
Configuration Status:
SUCCESS (status updated 44 seconds ago)
DGMGRL>
**CDB**DGMGRL> show configuration
DGMGRL> show configuration
Configuration - rds_dg
Protection Mode: MaxAvailability
Members:
rdscdb_b - Primary database
rdscdb_a - Physical standby database
Fast-Start Failover: Disabled
Configuration Status:
SUCCESS (status updated 52 seconds ago)
DGMGRL>
DGMGRL> show configuration lag
Configuration - rds_dg
Protection Mode: MaxAvailability
Members:
rdscdb_b - Primary database
rdscdb_a - Physical standby database
Transport Lag: 0 seconds (computed 0 seconds ago)
Apply Lag: 0 seconds (computed 0 seconds ago)
Fast-Start Failover: Disabled
Configuration Status:
SUCCESS (status updated 53 seconds ago)
DGMGRL>
| DBA |
| 在 Amazon RDS 主控台上驗證執行個體角色。 | 在您執行角色切換後，Amazon RDS 主控台會在**資料庫****連線與安全**索引標籤的**複寫**區段下顯示新角色。**複寫狀態**可能需要幾分鐘的時間才能從空白更新為**複寫**。 | DBA |
### 設定 FSFO
| 任務 | Description | 所需的技能 |
| --- | --- | --- |
| 重設切換。 | 將切換設回主節點。 | DBA |
| 安裝並啟動觀察者。 | 觀察者程序是`DGMGRL`用戶端元件，通常在與主要和待命資料庫不同的機器中執行。觀察者的 ORACLE HOME 安裝可以是 Oracle Client Administrator 安裝，也可以安裝 Oracle Database Enterprise Edition 或 Personal Edition。如需資料庫版本的觀察程式安裝詳細資訊，請參閱[安裝和啟動觀察程式](https://docs.oracle.com/en/database/oracle/oracle-database/19/dgbkr/using-data-guard-broker-to-manage-switchovers-failovers.html#GUID-11EF3897-8FCA-4A54-B63B-E8C1668AE21B)。若要設定觀察者程序的高可用性，建議您執行下列動作：[\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/zh_tw/prescriptive-guidance/latest/patterns/transition-roles-for-an-oracle-peoplesoft-application-on-amazon-rds-custom-for-oracle.html)對於 Oracle 12c 版本 2 和更新版本，您最多可以部署三個觀察者。一個觀察者是主要觀察者，其餘則是備份觀察者。當主要觀察者失敗時，其中一個備份觀察者會擔任主要角色。 | DBA |
| 從觀察者主機連線至 DGMGRL。 | 觀察者主機設定了主要和待命資料庫連線`tnsnames.ora`的項目。只要資料遺失在 [FastStartFailoverLagLimit](https://docs.oracle.com/en/database/oracle/oracle-database/19/dgbkr/oracle-data-guard-broker-properties.html) 組態 （以秒為單位的值） 內，您就可以啟用具有最大效能保護模式的 FSFO。不過，您必須使用最大可用性保護模式才能達到零資料遺失 (RPO=0)。**非 CDB**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 58 seconds ago)
DGMGRL> show configuration lag
Configuration - rds_dg
Protection Mode: MaxAvailability
Members:
orcl_a - Primary database
orcl_d - Physical standby database
Transport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 0 seconds (computed 1 second ago)
Fast-Start Failover: Disabled
Configuration Status:
SUCCESS (status updated 5 seconds ago)
DGMGRL>
**CDB**-bash-4.2$ dgmgrl C##RDS_DATAGUARD@RDS_CUSTOM_RDSCDB_A
DGMGRL for Linux: Release 19.0.0.0.0 - Production on Wed Jan 18 06:55:09 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_A"
Connected as SYSDG.
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 18 seconds ago)
DGMGRL>
| DBA |
| 將待命資料庫修改為容錯移轉目標。 | 從主節點或觀察者節點連線到一個待命資料庫。（雖然您的初始化可能具有 mulitiple 待命資料庫，但您目前只需要連線到一個。)**非 CDB**DGMGRL> edit database orcl_a set property FastStartFailoverTarget='orcl_d';
Property "faststartfailovertarget" updated
DGMGRL> edit database orcl_d set property FastStartFailoverTarget='orcl_a';
Property "faststartfailovertarget" updated
DGMGRL> show database orcl_a FastStartFailoverTarget;
FastStartFailoverTarget = 'orcl_d'
DGMGRL> show database orcl_d FastStartFailoverTarget;
FastStartFailoverTarget = 'orcl_a'
DGMGRL>
**CDB**DGMGRL> edit database orcl_a set property FastStartFailoverTarget='rdscdb_b';
Object "orcl_a" was not found
DGMGRL> edit database rdscdb_a set property FastStartFailoverTarget='rdscdb_b';
Property "faststartfailovertarget" updated
DGMGRL> edit database rdscdb_b set property FastStartFailoverTarget='rdscdb_a';
Property "faststartfailovertarget" updated
DGMGRL> show database rdscdb_a FastStartFailoverTarget;
FastStartFailoverTarget = 'rdscdb_b'
DGMGRL> show database rdscdb_b FastStartFailoverTarget;
FastStartFailoverTarget = 'rdscdb_a'
DGMGRL>
| DBA |
| 為 DGMGRL 的連線設定 FastStartFailoverThreshold。 | 在 Oracle 19c 中，預設值為 30 秒，最小值為 6 秒。較低的值可能會縮短容錯移轉期間的復原時間目標 (RTO)。較高的值有助於降低主要資料庫發生不必要的容錯移轉暫時性錯誤的機率。RDS Custom for Oracle 自動化架構會監控資料庫運作狀態，並每隔幾秒執行修正動作。因此，我們建議將 FastStartFailoverThreshold 設定為高於 10 秒的值。下列範例會將閾值設定為 35 秒。**非 CBD 或 CDB**DGMGRL> edit configuration set property FastStartFailoverThreshold=35;
Property "faststartfailoverthreshold" updated
DGMGRL> show configuration FastStartFailoverThreshold;
FastStartFailoverThreshold = '35'
DGMGRL>
| DBA |
| 從主要節點或觀察者節點連線至 DGMGRL 以啟用 FSFO。 | 如果資料庫未啟用 [Flashback 資料庫](https://docs.oracle.com/en/database/oracle/oracle-database/19/rcmrf/FLASHBACK-DATABASE.html#GUID-584AC79A-40C5-45CA-8C63-DED3BE3A4511)，則`ORA-16827`會顯示警告訊息。如果 [FastStartFailoverAutoReinstate](https://docs.oracle.com/en/database/oracle/oracle-database/19/dgbkr/oracle-data-guard-broker-properties.html#GUID-824E97C0-EEB0-4E1B-BD4A-F5AE282CEA28) 組態屬性設定為 `TRUE`（這是預設值），則選用的閃存資料庫有助於自動將失敗的主要資料庫恢復到容錯移轉之前的某個時間點。**非 CDB**DGMGRL> enable fast_start failover;
Warning: ORA-16827: Flashback Database is disabled
Enabled in Zero Data Loss Mode.
DGMGRL>
DGMGRL> show configuration
Configuration - rds_dg
Protection Mode: MaxAvailability
Members:
orcl_a - Primary database
Warning: ORA-16819: fast-start failover observer not started
orcl_d - (*) Physical standby database
Warning: ORA-16819: fast-start failover observer not started
Fast-Start Failover: Enabled in Zero Data Loss Mode
Configuration Status:
WARNING (status updated 29 seconds ago)
DGMGRL>
**CDB**DGMGRL> enable fast_start failover;
Warning: ORA-16827: Flashback Database is disabled
Enabled in Zero Data Loss Mode.
DGMGRL> show configuration;
Configuration - rds_dg
Protection Mode: MaxAvailability
Members:
rdscdb_a - Primary database
Warning: ORA-16819: fast-start failover observer not started
rdscdb_b - (*) Physical standby database
Fast-Start Failover: Enabled in Zero Data Loss Mode
Configuration Status:
WARNING (status updated 11 seconds ago)
DGMGRL>
| DBA |
| 啟動觀察者以進行 FSFO 監控，並驗證狀態。 | 您可以在啟用 FSFO 之前或之後啟動觀察者。如果已啟用 FSFO，觀察者會立即開始監控主要和目標待命資料庫的狀態和連線。如果未啟用 FSFO，在啟用 FSFO 之前，觀察者不會開始監控。當您啟動觀察者時，主要資料庫組態會顯示為沒有任何錯誤訊息，如上一個`show configuration`命令所證明。**非 CDB**DGMGRL> start observer;
[W000 2022-12-01T06:16:51.271+00:00] FSFO target standby is orcl_d
Observer 'ip-10-0-1-89' started
[W000 2022-12-01T06:16:51.352+00:00] Observer trace level is set to USER
DGMGRL> show configuration
Configuration - rds_dg
Protection Mode: MaxAvailability
Members:
orcl_a - Primary database
orcl_d - (*) Physical standby database
Fast-Start Failover: Enabled in Zero Data Loss Mode
Configuration Status:
SUCCESS (status updated 56 seconds ago)
DGMGRL>
DGMGRL> show observer
Configuration - rds_dg
Primary: orcl_a
Active Target: orcl_d
Observer "ip-10-0-1-89" - Master
Host Name: ip-10-0-1-89
Last Ping to Primary: 1 second ago
Last Ping to Target: 1 second ago
DGMGRL>
**CDB**DGMGRL> start observer;
Succeeded in opening the observer file "/home/oracle/fsfo_ip-10-0-1-56.dat".
[W000 2023-01-18T07:31:32.589+00:00] FSFO target standby is rdscdb_b
Observer 'ip-10-0-1-56' started
The observer log file is '/home/oracle/observer_ip-10-0-1-56.log'.
DGMGRL> show configuration
Configuration - rds_dg
Protection Mode: MaxAvailability
Members:
rdscdb_a - Primary database
rdscdb_b - (*) Physical standby database
Fast-Start Failover: Enabled in Zero Data Loss Mode
Configuration Status:
SUCCESS (status updated 12 seconds ago)
DGMGRL>
DGMGRL> show observer;
Configuration - rds_dg
Primary: rdscdb_a
Active Target: rdscdb_b
Observer "ip-10-0-1-56" - Master
Host Name: ip-10-0-1-56
Last Ping to Primary: 1 second ago
Last Ping to Target: 2 seconds ago
DGMGRL>
| DBA |
| 驗證容錯移轉。 | 在此案例中，可以透過手動停止主要 EC2 執行個體來執行容錯移轉測試。在停止 EC2 執行個體之前，請使用 `tail`命令，根據您的組態監控觀察者日誌檔案。使用 `DGMGRL`以`orcl_d`使用者 登入待命資料庫`RDS_DATAGUARD`，並檢查 Oracle Data Guard 狀態。它應該顯示 `orcl_d`是新的主要資料庫。在此容錯移轉測試案例中， `orcl_d`是非 CDB 資料庫。在容錯移轉之前，已在 上啟用快閃記憶體資料庫`orcl_a`。在前一個主要資料庫返回線上並開始處於 `MOUNT` 狀態後，觀察者會將其恢復為新的待命資料庫。恢復的資料庫可做為新主要資料庫的 FSFO 目標。您可以在觀察者日誌中驗證詳細資訊。DGMGRL> show configuration
Configuration - rds_dg
Protection Mode: MaxAvailability
Members:
orcl_d - Primary database
Warning: ORA-16824: multiple warnings, including fast-start failover-related warnings, detected for the database
orcl_a - (*) Physical standby database (disabled)
ORA-16661: the standby database needs to be reinstated
Fast-Start Failover: Enabled in Zero Data Loss Mode
Configuration Status:
WARNING (status updated 25 seconds ago)
DGMGRL>
以下顯示 中的範例輸出`observer.log`。$ tail -f /tmp/observer.log
Unable to connect to database using rds_custom_orcl_a
[W000 2023-01-18T07:50:32.589+00:00] Primary database cannot be reached.
[W000 2023-01-18T07:50:32.589+00:00] Fast-Start Failover threshold has expired.
[W000 2023-01-18T07:50:32.590+00:00] Try to connect to the standby.
[W000 2023-01-18T07:50:32.590+00:00] Making a last connection attempt to primary database before proceeding with Fast-Start Failover.
[W000 2023-01-18T07:50:32.591+00:00] Check if the standby is ready for failover.
[S002 2023-01-18T07:50:32.591+00:00] Fast-Start Failover started...
2023-01-18T07:50:32.591+00:00
Initiating Fast-Start Failover to database "orcl_d"...
[S002 2023-01-18T07:50:32.592+00:00] Initiating Fast-start Failover.
Performing failover NOW, please wait...
Failover succeeded, new primary is "orcl_d"
2023-01-18T07:55:32.101+00:00
[S002 2023-01-18T07:55:32.591+00:00] Fast-Start Failover finished...
[W000 2023-01-18T07:55:32.591+00:00] Failover succeeded. Restart pinging.
[W000 2023-01-18T07:55:32.603+00:00] Primary database has changed to orcl_d.
[W000 2023-01-18T07:55:33.618+00:00] Try to connect to the primary.
[W000 2023-01-18T07:55:33.622+00:00] Try to connect to the primary rds_custom_orcl_d.
[W000 2023-01-18T07:55:33.634+00:00] The standby orcl_a needs to be reinstated
[W000 2023-01-18T07:55:33.654+00:00] Try to connect to the new standby orcl_a.
[W000 2023-01-18T07:55:33.654+00:00] Connection to the primary restored!
[W000 2023-01-18T07:55:35.654+00:00] Disconnecting from database rds_custom_orcl_d.
[W000 2023-01-18T07:55:57.701+00:00] Try to connect to the new standby orcl_a.
ORA-12170: TNS:Connect timeout occurred
| DBA |
### 設定 Oracle Peoplesoft 應用程式與資料庫之間的連線
| 任務 | Description | 所需的技能 |
| --- | --- | --- |
| 在主要資料庫中建立和啟動服務。 | 您可以使用同時包含組態中主要和待命資料庫端點的 TNS 項目，以避免角色轉換期間的應用程式組態變更。您可以定義兩個角色型資料庫服務，以支援讀取/寫入和唯讀工作負載。在下列範例中， `orcl_rw`是主要資料庫上作用中的讀取/寫入服務。 `orcl_ro`是唯讀服務，並且是已在唯讀模式中開啟的待命資料庫上作用中。SQL> select name,open_mode from v$database;
NAME OPEN_MODE
--------- --------------------
ORCL READ WRITE
SQL> exec dbms_service.create_service('orcl_rw','orcl_rw');
PL/SQL procedure successfully completed.
SQL> exec dbms_service.create_service('orcl_ro','orcl_ro');
PL/SQL procedure successfully completed.
SQL> exec dbms_service.start_service('orcl_rw');
PL/SQL procedure successfully completed.
SQL>
| DBA |
| 在待命資料庫中啟動服務。 | 若要在唯讀待命資料庫中啟動服務，請使用下列程式碼。SQL> select name,open_mode from v$database;
NAME OPEN_MODE
--------- --------------------
ORCL READ ONLY WITH APPLY
SQL> exec dbms_service.start_service('orcl_ro');
PL/SQL procedure successfully completed.
SQL>
| DBA |
| 重新啟動主要資料庫時，自動啟動服務。 | 若要在重新啟動時在主要資料庫中自動啟動服務，請使用下列程式碼。SQL> CREATE OR REPLACE TRIGGER TrgDgServices after startup on database
DECLARE
db_role VARCHAR(30);
db_open_mode VARCHAR(30);
BEGIN
SELECT DATABASE_ROLE, OPEN_MODE INTO db_role, db_open_mode FROM V$DATABASE;
IF db_role = 'PRIMARY' THEN
DBMS_SERV 2 ICE.START_SERVICE('orcl_rw');
END IF;
IF db_role = 'PHYSICAL STANDBY' AND db_open_mode LIKE 'READ ONLY%' THEN
DBMS_SERVICE.START_SERVICE('orcl_ro');
END IF;
END;
/
Trigger created.
SQL>
| DBA |
| 設定讀取/寫入和唯讀資料庫之間的連線。 | 您可以針對讀取/寫入和唯讀連線使用下列應用程式組態範例。ORCL_RW = (DESCRIPTION =
(CONNECT_TIMEOUT= 120)(RETRY_COUNT=20)(RETRY_DELAY=3)(TRANSPORT_CONNECT_TIMEOUT=3)
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST=devpsftdb.******.us-west-2.rds.amazonaws.com)(PORT=1521))
(ADDRESS = (PROTOCOL = TCP)(HOST=psftread.******.us-west-2.rds.amazonaws.com)(PORT=1521))
)
(CONNECT_DATA=(SERVICE_NAME = orcl_rw))
)
ORCL_RO = (DESCRIPTION =
(CONNECT_TIMEOUT= 120)(RETRY_COUNT=20)(RETRY_DELAY=3)(TRANSPORT_CONNECT_TIMEOUT=3)
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST=devpsftdb.******.us-west-2.rds.amazonaws.com)(PORT=1521))
(ADDRESS = (PROTOCOL = TCP)(HOST=psftread.******.us-west-2.rds.amazonaws.com)(PORT=1521))
)
(CONNECT_DATA=(SERVICE_NAME = orcl_ro))
)
| DBA |
## 相關資源
+ [使用 Amazon RDS Custom for Oracle 上的 Data Guard 啟用高可用性](https://d1.awsstatic.com/whitepapers/enabling-high-availability-with-data-guard-on-amazon-rds-custom-for-oracle.pdf) (AWS 技術指南）
+ [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）
+ [Oracle Data Guard 特定 FAN 和 FCF 組態需求 ](https://docs.oracle.com/en/database/oracle/oracle-database/19/dgbkr/using-data-guard-broker-to-manage-switchovers-failovers.html#GUID-DFFDAA2B-A889-49AD-AB85-747D73FF0FF5)(Oracle 參考文件）