Question

How can I scale my Amazon RDS database?

Answer 1

Scaling your Amazon RDS database involves adjusting the compute, memory, and storage resources to match your application's requirements. RDS provides several options to scale your database:

1. Scaling Compute and Memory (Instance Class)

You can change the DB instance class to a larger or smaller instance type to scale up or down the compute and memory resources.

Using AWS Management Console:

1. Go to the RDS Dashboard.
2. Select your DB instance.
3. Choose "Modify."
4. Select a new instance class.
5. Apply the changes immediately or during the next maintenance window.

Using AWS CLI:

aws rds modify-db-instance \
    --db-instance-identifier mydbinstance \
    --db-instance-class db.m5.large \
    --apply-immediately 

This command modifies mydbinstance to use the db.m5.large instance class and applies the changes immediately.

2. Scaling Storage

You can increase the allocated storage for your DB instance. Note that you can only increase storage, not decrease it.

Using AWS Management Console:

1. Go to the RDS Dashboard.
2. Select your DB instance.
3. Choose "Modify."
4. Increase the allocated storage.
5. Apply the changes immediately or during the next maintenance window.

Using AWS CLI:

aws rds modify-db-instance \
    --db-instance-identifier mydbinstance \
    --allocated-storage 100 \
    --apply-immediately 

This command modifies mydbinstance to increase the allocated storage to 100 GB and applies the changes immediately.

3. Scaling Storage Type

You can change the storage type to optimize performance or cost.

Using AWS Management Console:

1. Go to the RDS Dashboard.
2. Select your DB instance.
3. Choose "Modify."
4. Change the storage type (e.g., from General Purpose SSD to Provisioned IOPS SSD).
5. Apply the changes immediately or during the next maintenance window.

Using AWS CLI:

aws rds modify-db-instance \
    --db-instance-identifier mydbinstance \
    --storage-type io1 \
    --iops 10000 \
    --apply-immediately 

This command modifies mydbinstance to use Provisioned IOPS SSD storage with 10,000 IOPS and applies the changes immediately.

4. Using Read Replicas

You can create read replicas to offload read traffic from your primary database and enhance read scalability.

Creating a Read Replica Using AWS Management Console:

1. Go to the RDS Dashboard.
2. Select your DB instance.
3. Choose "Actions" and then "Create read replica."
4. Configure the read replica settings.
5. Create the read replica.

Creating a Read Replica Using AWS CLI:

aws rds create-db-instance-read-replica \
    --db-instance-identifier mydbinstance-replica \
    --source-db-instance-identifier mydbinstance 

This command creates a read replica of mydbinstance named mydbinstance-replica.

5. Multi-AZ Deployments

For high availability and failover support, you can enable Multi-AZ deployments. This automatically replicates your database to a standby instance in a different Availability Zone.

Enabling Multi-AZ Using AWS Management Console:

1. Go to the RDS Dashboard.
2. Select your DB instance.
3. Choose "Modify."
4. Enable "Multi-AZ deployment."
5. Apply the changes immediately or during the next maintenance window.

Enabling Multi-AZ Using AWS CLI:

aws rds modify-db-instance \
    --db-instance-identifier mydbinstance \
    --multi-az \
    --apply-immediately 

This command enables Multi-AZ deployment for mydbinstance and applies the changes immediately.

6. Horizontal Scaling with Amazon Aurora

If you are using Amazon Aurora, you can take advantage of its unique features for horizontal scaling:

• Aurora Replicas: Create up to 15 read replicas for read scaling.
• Aurora Global Database: Span your database across multiple AWS regions for low-latency reads and disaster recovery.

Creating an Aurora Replica Using AWS CLI:

aws rds create-db-cluster \
    --db-cluster-identifier myauroracluster \
    --engine aurora \
    --master-username masteruser \
    --master-user-password masterpassword

aws rds create-db-instance \
    --db-instance-identifier myaurorainstance \
    --db-cluster-identifier myauroracluster \
    --engine aurora \
    --db-instance-class db.r5.large 

This command creates an Aurora cluster and an Aurora instance within that cluster.

Monitoring and Maintenance

Regularly monitor your database performance and resource utilization using Amazon CloudWatch and RDS Performance Insights. Schedule maintenance windows to apply updates and modifications with minimal disruption.