Modifying an RDS Custom for Oracle Single-AZ deployment to a Multi-AZ deployment - Amazon Relational Database Service
Configuring prerequisites to modify a Single-AZ to a Multi-AZ deployment using CloudFormationConfiguring prerequisites to modify a Single-AZ to a Multi-AZ deployment manuallyModify using the RDS console, Amazon CLI, or RDS API
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Modifying an RDS Custom for Oracle Single-AZ deployment to a Multi-AZ deployment

You can modify an existing multi-AZ compatible RDS Custom for Oracle instance from a Single-AZ deployment to a Multi-AZ deployment. When you modify the DB instance, Amazon RDS performs several actions:

  • Takes a snapshot of the primary DB instance.

  • Creates new volumes for the standby replica from the snapshot. These volumes initialize in the background, and maximum volume performance is achieved after the data is fully initialized.

  • Turns on synchronous block-level replication between the primary and standby DB instances.

Important

We recommend that you avoid modifying your RDS Custom for Oracle DB instance from a Single-AZ to a Multi-AZ deployment on a production DB instance during periods of peak activity.

Amazon uses a snapshot to create the standby instance to avoid downtime when you convert from Single-AZ to Multi-AZ, but performance might be impacted during and after converting to Multi-AZ. This impact can be significant for workloads that are sensitive to write latency. While this capability allows large volumes to quickly be restored from snapshots, it can cause increase in the latency of I/O operations because of the synchronous replication. This latency can impact your database performance.

Configuring prerequisites to modify a Single-AZ to a Multi-AZ deployment using CloudFormation

Follow Step 3: Extract the CloudFormation templates for RDS Custom for Oracle to setup your VPC and IAM profile again to add SQS VPC endpoint and SQS permission in IAM profile.

Configuring prerequisites to modify a Single-AZ to a Multi-AZ deployment manually

If you choose to configure the prerequisites manually, perform the following tasks.

  1. Open the Amazon VPC console at https://console.aws.amazon.com/vpc/

  2. Choose Endpoint. The Create Endpoint page appears.

  3. For Service Category, choose Amazon services.

  4. In Services, search for SQS.

  5. In VPC, choose the VPC where your RDS Custom for Oracle DB instance is deployed.

  6. In Subnets, choose the subnets where your RDS Custom for Oracle DB instance is deployed.

  7. In Security Groups, choose the security group where your RDS Custom for Oracle DB instance is deployed.

  8. For Policy, choose Custom.

  9. In your custom policy, replace the AWS partition, Region, accountId, and IAM-Instance-role with your own values.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Condition": {
                "StringLike": {
                    "aws:ResourceTag/AWSRDSCustom": "custom-oracle"
                }
            },
            "Action": [
                "SQS:SendMessage",
                "SQS:ReceiveMessage",
                "SQS:DeleteMessage",
                "SQS:GetQueueUrl"
            ],
            "Resource": "arn:${AWS::Partition}:sqs:${AWS::Region}:${AWS::AccountId}:do-not-delete-rds-custom-*",
            "Effect": "Allow",
            "Principal": {
                "AWS": "arn:${AWS::Partition}:iam::${AWS::AccountId}:role/{IAM-Instance-role}"
            }
        }
    ]
}

Update the Instance profile with permission to access Amazon SQS. Replace the AWS partition, Region, and accountId with your own values.

{
    "Sid": "13",
    "Effect": "Allow",
    "Action": [
        "SQS:SendMessage",
        "SQS:ReceiveMessage",
        "SQS:DeleteMessage",
        "SQS:GetQueueUrl"
    ],
    "Resource": [
        {
            "Fn::Sub": "arn:${AWS::Partition}:sqs:${AWS::Region}:${AWS::AccountId}:do-not-delete-rds-custom-*"
        }
    ],
    "Condition": {
        "StringLike": {
            "aws:ResourceTag/AWSRDSCustom": "custom-oracle"
        }
    }
}

Update the Amazon RDS security group inbound and outbound rules to allow port 1120.

  • In Security Groups, choose the group where your RDS Custom for Oracle DB instance is deployed.

  • For Inbound Rules, create a Custom TCP rule to allow port 1120 from the source group.

  • For Outbound Rules, create a Custom TCP rule to allow port 1120 to the destination group.

Modify using the RDS console, Amazon CLI, or RDS API

After you've completed the prerequisites, you can modify an RDS Custom for Oracle DB instance from a Single-AZ to Multi-AZ deployment using the Amazon RDS console, Amazon CLI, or Amazon RDS API.

Console

To modify an existing RDS Custom for Oracle Single-AZ to Multi-AZ deployment

  1. Sign in to the Amazon Management Console and open the Amazon RDS console at https://console.amazonaws.cn/rds/.

  2. In the Amazon RDS console, choose Databases. The Databases pane appears.

  3. Choose the RDS Custom for Oracle DB instance that you want to modify.

  4. For Actions, choose Convert to Multi-AZ deployment.

  5. On the Confirmation page, choose Apply immediately to apply the changes immediately. Choosing this option doesn't cause downtime, but there is a possible performance impact. Alternatively, you can choose to apply the update during the next maintenance window. For more information, see Using the schedule modifications setting.

  6. On the Confirmation page, choose Convert to Multi-AZ.

Amazon CLI

To convert to a Multi-AZ DB instance deployment by using the Amazon CLI, call the modify-db-instance command and set the --multi-az option. Specify the DB instance identifier and the values for other options that you want to modify. For information about each option, see Settings for DB instances.

Example

The following code modifies mycustomdbinstance by including the --multi-az option. The changes are applied during the next maintenance window by using --no-apply-immediately. Use --apply-immediately to apply the changes immediately. For more information, see Using the schedule modifications setting.

For Linux, macOS, or Unix:

aws rds modify-db-instance \
    --db-instance-identifier mycustomdbinstance \
    --multi-az \
    [--no-apply-immediately | --apply-immediately]

For Windows:

aws rds modify-db-instance ^
    --db-instance-identifier mycustomdbinstance ^
    --multi-az ^
    [--no-apply-immediately | --apply-immediately]

RDS API

To convert to a Multi-AZ DB instance deployment with the Amazon RDS API, call the ModifyDBInstance operation and set the MultiAZ parameter to true.