Managing an Amazon RDS Custom for Oracle DB instance

Amazon RDS Custom supports a subset of the usual management tasks for Amazon RDS DB instances. Following, you can find instructions for the supported RDS Custom for Oracle management tasks using the Amazon Web Services Management Console and the Amazon CLI.

Working with container databases (CDBs) in RDS Custom for Oracle

You can either create your RDS Custom for Oracle DB instance with the Oracle Multitenant architecture (custom-oracle-ee-cdb engine type) or with the traditional non-CDB architecture (custom-oracle-ee engine type). When you create a container database (CDB), it contains one pluggable database (PDB) and one PDB seed. You can create additional PDBs manually using Oracle SQL.

PDB and CDB names

When you create an RDS Custom for Oracle CDB instance, you specify a name for the initial PDB. By default, your initial PDB is named ORCL. You can choose a different name.

By default, your CDB is named RDSCDB. You can choose a different name. The CDB name is also the name of your Oracle system identifier (SID), which uniquely identifies the memory and processes that manage your CDB. For more information about the Oracle SID, see Oracle System Identifier (SID) in Oracle Database Concepts.

You can't rename existing PDBs using Amazon RDS APIs. You also can't rename the CDB using the modify-db-instance command.

PDB management

In the RDS Custom for Oracle shared responsibility model, you are responsible for managing PDBs and creating any additional PDBs. RDS Custom doesn't restrict the number of PDBs. You can manually create, modify, and delete PDBs by connecting to the CDB root and running a SQL statement. Create PDBs on an Amazon EBS data volume to prevent the DB instance from going outside the support perimeter.

To modify your CDBs or PDBs, complete the following steps:

Automatic recovery of the CDB root

RDS Custom keeps the CDB root open in the same way as it keeps a non-CDB open. If the state of the CDB root changes, the monitoring and recovery automation attempts to recover the CDB root to the desired state. You receive RDS event notifications when the root CDB is shut down (RDS-EVENT-0004) or restarted (RDS-EVENT-0006), similar to the non-CDB architecture. RDS Custom attempts to open all PDBs in READ WRITE mode at DB instance startup. If some PDBs can't be opened, RDS Custom publishes the following event: tenant database shutdown.

Working with high availability features for RDS Custom for Oracle

To support replication between RDS Custom for Oracle instances, you can configure high availability (HA) with Oracle Data Guard. The primary DB instance automatically synchronizes data to the standby instances.

You can configure your high availability environment in the following ways:

To learn how to configure high availability, see the whitepaper Build high availability for Amazon RDS Custom for Oracle using read replicas. You can perform the following tasks:

Customizing your RDS Custom environment

RDS Custom for Oracle includes built-in features that allow you to customize your DB instance environment without pausing automation. For example, you can use RDS APIs to customize your environment as follows:

For some customizations, such as changing the time zone or character set, you can't use the RDS APIs. In these cases, you need to change the environment manually by accessing your Amazon EC2 instance as the root user or logging in to your Oracle database as SYSDBA.

To customize your instance manually, you must pause and resume RDS Custom automation. This pause ensures that your customizations don't interfere with RDS Custom automation. In this way, you avoid breaking the support perimeter, which places the instance in the unsupported-configuration state until you fix the underlying issues. Pausing and resuming are the only supported automation tasks when you modify an RDS Custom for Oracle DB instance.

General steps for customizing your RDS Custom environment

To customize your RDS Custom DB instance, complete the following steps:

For best practices and step-by-step instructions, see the Amazon blog posts Make configuration changes to an Amazon RDS Custom for Oracle instance: Part 1 and Recreate an Amazon RDS Custom for Oracle database: Part 2.

Pausing and resuming your RDS Custom DB instance

You can pause and resume automation for your DB instance using the console or CLI.

aws rds modify-db-instance \
    --db-instance-identifier my-custom-instance \
    --automation-mode all-paused \
    --resume-full-automation-mode-minutes 90

aws rds modify-db-instance ^
    --db-instance-identifier my-custom-instance ^
    --automation-mode all-paused ^
    --resume-full-automation-mode-minutes 90

aws rds modify-db-instance \
    --db-instance-identifier my-custom-instance \
    --automation-mode all-paused \
    --resume-full-automation-mode-minutes 30

aws rds modify-db-instance ^
    --db-instance-identifier my-custom-instance ^
    --automation-mode all-paused ^
    --resume-full-automation-mode-minutes 30

aws rds modify-db-instance \
    --db-instance-identifier my-custom-instance \
    --automation-mode full \

aws rds modify-db-instance ^
    --db-instance-identifier my-custom-instance ^
    --automation-mode full

{
    "DBInstance": {
        "PubliclyAccessible": true,
        "MasterUsername": "admin",
        "MonitoringInterval": 0,
        "LicenseModel": "bring-your-own-license",
        "VpcSecurityGroups": [
            {
                "Status": "active",
                "VpcSecurityGroupId": "0123456789abcdefg"
            }
        ],
        "InstanceCreateTime": "2020-11-07T19:50:06.193Z",
        "CopyTagsToSnapshot": false,
        "OptionGroupMemberships": [
            {
                "Status": "in-sync",
                "OptionGroupName": "default:custom-oracle-ee-19"
            }
        ],
        "PendingModifiedValues": {
            "AutomationMode": "full"
        },
        "Engine": "custom-oracle-ee",
        "MultiAZ": false,
        "DBSecurityGroups": [],
        "DBParameterGroups": [
            {
                "DBParameterGroupName": "default.custom-oracle-ee-19",
                "ParameterApplyStatus": "in-sync"
            }
        ],
        ...
        "ReadReplicaDBInstanceIdentifiers": [],
        "AllocatedStorage": 250,
        "DBInstanceArn": "arn:aws:rds:us-west-2:012345678912:db:my-custom-instance",
        "BackupRetentionPeriod": 3,
        "DBName": "ORCL",
        "PreferredMaintenanceWindow": "fri:10:56-fri:11:26",
        "Endpoint": {
            "HostedZoneId": "ABCDEFGHIJKLMNO",
            "Port": 8200,
            "Address": "my-custom-instance.abcdefghijk.us-west-2.rds.amazonaws.com"
        },
        "DBInstanceStatus": "automation-paused",
        "IAMDatabaseAuthenticationEnabled": false,
        "AutomationMode": "all-paused",
        "EngineVersion": "19.my_cev1",
        "DeletionProtection": false,
        "AvailabilityZone": "us-west-2a",
        "DomainMemberships": [],
        "StorageType": "gp2",
        "DbiResourceId": "db-ABCDEFGHIJKLMNOPQRSTUVW",
        "ResumeFullAutomationModeTime": "2020-11-07T20:56:50.565Z",
        "KmsKeyId": "arn:aws:kms:us-west-2:012345678912:key/aa111a11-111a-11a1-1a11-1111a11a1a1a",
        "StorageEncrypted": false,
        "AssociatedRoles": [],
        "DBInstanceClass": "db.m5.xlarge",
        "DbInstancePort": 0,
        "DBInstanceIdentifier": "my-custom-instance",
        "TagList": []
    }

Modifying your RDS Custom for Oracle DB instance

Modifying an RDS Custom for Oracle DB instance is similar to modifying an Amazon RDS instance, but you can only do the following:

Requirements and limitations when modifying your DB instance storage

Consider the following requirements and limitations when you modify the storage for an RDS Custom for Oracle DB instance:

For more information about Amazon EBS storage, see Amazon RDS DB instance storage. For general information about storage modification, see Working with storage for Amazon RDS DB instances.

Requirements and limitations when modifying your DB instance class

Consider the following requirements and limitations when you modify the instance class for an RDS Custom for Oracle DB instance:

How RDS Custom creates your DB instance when you modify the instance class

When you modify your instance class, RDS Custom creates your DB instance as follows:

Modifying the instance class or storage for your RDS Custom for Oracle DB instance

You can modify the DB instance class or storage using the console, Amazon CLI, or RDS API.

aws rds modify-db-instance \
    --db-instance-identifier my-custom-instance \
    --db-instance-class db.m5.16xlarge \
    --storage-type io1 \
    --iops 3000 \
    --allocated-storage 1024 \
    --apply-immediately

aws rds modify-db-instance ^
    --db-instance-identifier my-custom-instance ^
    --db-instance-class db.m5.16xlarge ^
    --storage-type io1 ^
    --iops 3000 ^
    --allocated-storage 1024 ^
    --apply-immediately

Changing the time zone of an RDS Custom for Oracle DB instance

You change the time zone of an RDS Custom for Oracle DB instance manually. This approach contrasts with RDS for Oracle, where you use the TIME_ZONE option in a custom DB option group.

You can change time zones for RDS Custom for Oracle DB instances multiple times. However, we recommend not changing them more than once every 48 hours. We also recommend changing them only when the latest restorable time is within the last 30 minutes.

If you don't follow these recommendations, cleaning up redo logs might remove more logs than intended. Redo log timestamps might also be converted incorrectly to UTC, which can prevent the redo log files from being downloaded and replayed correctly. This in turn can prevent point-in-time recovery (PITR) from performing correctly.

Changing the time zone of an RDS Custom for Oracle DB instance has the following limitations:

Use the following procedures to change the time zone of an RDS Custom for Oracle DB instance.

Make sure to follow these procedures. If they aren't followed, it can result in these issues:

Changing the character set of an RDS Custom for Oracle DB instance

RDS Custom for Oracle defaults to the character set US7ASCII. You might want to specify different character sets to meet language or multibyte character requirements. When you use RDS Custom for Oracle, you can pause automation and then change the character set of your database manually.

Changing the character set of an RDS Custom for Oracle DB instance has the following requirements:

Setting the NLS_LANG value in RDS Custom for Oracle

A locale is a set of information addressing linguistic and cultural requirements that corresponds to a given language and country. To specify locale behavior for Oracle software, set the NLS_LANG environment variable on your client host. This variable sets the language, territory, and character set used by the client application in a database session.

For RDS Custom for Oracle, you can set only the language in the NLS_LANG variable: the territory and character use defaults. The language is used for Oracle database messages, collation, day names, and month names. Each supported language has a unique name, for example, American, French, or German. If language is not specified, the value defaults to American.

After you create your RDS Custom for Oracle database, you can set NLS_LANG on your client host to a language other than English. To see a list of languages supported by Oracle Database, log in to your RDS Custom for Oracle database and run the following query:

SELECT VALUE FROM V$NLS_VALID_VALUES WHERE PARAMETER='LANGUAGE' ORDER BY VALUE;

You can set NLS_LANG on the host command line. The following example sets the language to German for your client application using the Z shell on Linux.

export NLS_LANG=German

Your application reads the NLS_LANG value when it starts and then communicates it to the database when it connects.

For more information, see Choosing a Locale with the NLS_LANG Environment Variable in the Oracle Database Globalization Support Guide.

Support for Transparent Data Encryption

RDS Custom supports Transparent Data Encryption (TDE) for RDS Custom for Oracle DB instances.

However, you can't enable TDE using an option in a custom option group as you can in RDS for Oracle. You turn on TDE manually. For information about using Oracle Transparent Data Encryption, see Securing stored data using Transparent Data Encryption in the Oracle documentation.

Tagging RDS Custom for Oracle resources

You can tag RDS Custom resources as with Amazon RDS resources, but with some important differences:

For general information about resource tagging, see Tagging Amazon RDS resources.

Deleting an RDS Custom for Oracle DB instance

To delete an RDS Custom DB instance, do the following:

You can delete an RDS Custom DB instance using the console or the CLI. The time required to delete the DB instance can vary depending on the backup retention period (that is, how many backups to delete) and how much data is deleted.

aws rds delete-db-instance \
    --db-instance-identifier my-custom-instance \
    --skip-final-snapshot \
    --no-delete-automated-backups

aws rds delete-db-instance ^
    --db-instance-identifier my-custom-instance ^
    --skip-final-snapshot ^
    --no-delete-automated-backups