README.md

Amazon Relational Database Service Construct Library

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This is a developer preview (public beta) module.

All classes with the Cfn prefix in this module (CFN Resources) are auto-generated from CloudFormation. They are stable and safe to use.

However, all other classes, i.e., higher level constructs, are under active development and subject to non-backward compatible changes or removal in any future version. These are not subject to the Semantic Versioning model. This means that while you may use them, you may need to update your source code when upgrading to a newer version of this package.

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Starting a Clustered Database

To set up a clustered database (like Aurora), define a DatabaseCluster. You must always launch a database in a VPC. Use the vpcSubnets attribute to control whether your instances will be launched privately or publicly:

const cluster = new DatabaseCluster(this, 'Database', {
    engine: DatabaseClusterEngine.AURORA,
    masterUser: {
        username: 'admin'
    },
    instanceProps: {
        instanceType: ec2.InstanceType.of(ec2.InstanceClass.BURSTABLE2, ec2.InstanceSize.SMALL),
        vpcSubnets: {
            subnetType: ec2.SubnetType.PUBLIC,
        },
        vpc
    }
});

By default, the master password will be generated and stored in AWS Secrets Manager with auto-generated description.

Your cluster will be empty by default. To add a default database upon construction, specify the defaultDatabaseName attribute.

Starting an Instance Database

To set up a instance database, define a DatabaseInstance. You must always launch a database in a VPC. Use the vpcSubnets attribute to control whether your instances will be launched privately or publicly:

const instance = new DatabaseInstance(stack, 'Instance', {
    engine: rds.DatabaseInstanceEngine.ORACLE_SE1,
    instanceClass: ec2.InstanceType.of(ec2.InstanceClass.BURSTABLE2, ec2.InstanceSize.SMALL),
    masterUsername: 'syscdk',
    vpc
});

By default, the master password will be generated and stored in AWS Secrets Manager.

To use the storage auto scaling option of RDS you can specify the maximum allocated storage. This is the upper limit to which RDS can automatically scale the storage. More info can be found here Example for max storage configuration:

const instance = new DatabaseInstance(stack, 'Instance', {
    engine: rds.DatabaseInstanceEngine.ORACLE_SE1,
    instanceClass: ec2.InstanceType.of(ec2.InstanceClass.BURSTABLE2, ec2.InstanceSize.SMALL),
    masterUsername: 'syscdk',
    vpc,
    maxAllocatedStorage: 200
});

Use DatabaseInstanceFromSnapshot and DatabaseInstanceReadReplica to create an instance from snapshot or a source database respectively:

new DatabaseInstanceFromSnapshot(stack, 'Instance', {
    snapshotIdentifier: 'my-snapshot',
    engine: rds.DatabaseInstanceEngine.POSTGRES,
    instanceClass: ec2.InstanceType.of(ec2.InstanceClass.BURSTABLE2, ec2.InstanceSize.LARGE),
    vpc
});

new DatabaseInstanceReadReplica(stack, 'ReadReplica', {
    sourceDatabaseInstance: sourceInstance,
    engine: rds.DatabaseInstanceEngine.POSTGRES,
    instanceClass: ec2.InstanceType.of(ec2.InstanceClass.BURSTABLE2, ec2.InstanceSize.LARGE),
    vpc
});

Creating a "production" Oracle database instance with option and parameter groups:

example of setting up a production oracle instance

Instance events

To define Amazon CloudWatch event rules for database instances, use the onEvent method:

const rule = instance.onEvent('InstanceEvent', { target: new targets.LambdaFunction(fn) });

Connecting

To control who can access the cluster or instance, use the .connections attribute. RDS databases have a default port, so you don't need to specify the port:

cluster.connections.allowFromAnyIpv4('Open to the world');

The endpoints to access your database cluster will be available as the .clusterEndpoint and .readerEndpoint attributes:

const writeAddress = cluster.clusterEndpoint.socketAddress;   // "HOSTNAME:PORT"

For an instance database:

const address = instance.instanceEndpoint.socketAddress;   // "HOSTNAME:PORT"

Rotating credentials

When the master password is generated and stored in AWS Secrets Manager, it can be rotated automatically:

instance.addRotationSingleUser(); // Will rotate automatically after 30 days

example of setting up master password rotation for a cluster

The multi user rotation scheme is also available:

instance.addRotationMultiUser('MyUser', {
  secret: myImportedSecret // This secret must have the `masterarn` key
});

It's also possible to create user credentials together with the instance/cluster and add rotation:

const myUserSecret = new rds.DatabaseSecret(this, 'MyUserSecret', {
  username: 'myuser'
  masterSecret: instance.secret
});
const myUserSecretAttached = myUserSecret.attach(instance); // Adds DB connections information in the secret

instance.addRotationMultiUser('MyUser', { // Add rotation using the multi user scheme
  secret: myUserSecretAttached
});

Note: This user must be created manually in the database using the master credentials. The rotation will start as soon as this user exists.

See also @aws-cdk/aws-secretsmanager for credentials rotation of existing clusters/instances.

Metrics

Database instances expose metrics (cloudwatch.Metric):

// The number of database connections in use (average over 5 minutes)
const dbConnections = instance.metricDatabaseConnections();

// The average amount of time taken per disk I/O operation (average over 1 minute)
const readLatency = instance.metric('ReadLatency', { statistic: 'Average', periodSec: 60 });