By UATeam in AWS —

AWS DynamoDB Global Tables Example: A Comprehensive Guide

Amazon DynamoDB Global Tables provide a fully managed, multi-region, and multi-active database solution for applications requiring low-latency access across the globe. By replicating data across multiple AWS Regions, global tables enable seamless data synchronization and disaster recovery.

This article provides a practical example of setting up and using AWS DynamoDB Global Tables to replicate data between two AWS Regions.

What Are DynamoDB Global Tables?

DynamoDB Global Tables allow you to:

  • Replicate Data Globally: Automatically synchronize data across selected AWS Regions.
  • Reduce Latency: Serve read and write requests from the nearest Region.
  • Ensure High Availability: Provide disaster recovery by replicating data across regions.

AWS DynamoDB Global Tables Example

Objective

We’ll create a DynamoDB table with global replication between two regions (e.g., us-east-1 and us-west-2) to handle a globally distributed application.

Step 1: Create a DynamoDB Table

  1. Navigate to the DynamoDB Console:
    • Go to the AWS Management Console → DynamoDB → Create Table.
  2. Configure Table Settings:
    • Table Name: GlobalUsers.
    • Primary Key: UserId (String).
    • Billing Mode: On-Demand for simplicity.
    • Encryption: Use default AWS-owned CMK.
  3. Click Create Table.

Step 2: Enable Global Tables

Add a Region for Replication

  1. In the DynamoDB Console, select the GlobalUsers table.
  2. Navigate to the Global Tables tab → Add Region.
  3. Select the region to replicate to (e.g., us-west-2).
  4. Click Create Replica.

Automatic Replication

DynamoDB will automatically set up the global table and replicate existing data to the selected region.

Step 3: Insert and Query Data

Insert Data

Use the AWS CLI to insert data into the table:

aws dynamodb put-item \
    --table-name GlobalUsers \
    --region us-east-1 \
    --item '{"UserId": {"S": "user123"}, "Name": {"S": "John Doe"}, "Email": {"S": "john.doe@example.com"}}'

Query Data from Another Region

Query the data from the replica region:

aws dynamodb get-item \
    --table-name GlobalUsers \
    --region us-west-2 \
    --key '{"UserId": {"S": "user123"}}'

Step 4: Test Global Data Synchronization

Query the data from us-east-1:

aws dynamodb get-item \
    --table-name GlobalUsers \
    --region us-east-1 \
    --key '{"UserId": {"S": "user456"}}'

Add a new item in us-west-2:

aws dynamodb put-item \
    --table-name GlobalUsers \
    --region us-west-2 \
    --item '{"UserId": {"S": "user456"}, "Name": {"S": "Jane Smith"}, "Email": {"S": "jane.smith@example.com"}}'

The data will appear in both regions almost instantly.

Step 5: Monitor and Optimize

Monitor Replication

  • Use the CloudWatch Console to monitor replication latency and throughput.
  • Metrics like ReplicationLatency help identify bottlenecks.

Optimize Costs

  • Use provisioned capacity for predictable workloads.
  • Consolidate read and write operations to minimize costs.

Best Practices for DynamoDB Global Tables

  1. Choose Regions Strategically:
    • Replicate to regions closest to your users for lower latency.
  2. Handle Conflicts:
    • DynamoDB uses a last-write-wins strategy. Design your application to handle conflicts gracefully.
  3. Monitor Costs:
    • Monitor regional read/write usage to avoid unexpected charges.
  4. Enable Encryption:
    • Use AWS Key Management Service (KMS) for enhanced security.

Use Cases for DynamoDB Global Tables

  1. Multi-Region Applications:
    • Serve global users with low-latency data access.
  2. Disaster Recovery:
    • Ensure high availability by replicating data across regions.
  3. IoT Applications:
    • Collect and process IoT data from devices distributed worldwide.

Conclusion

AWS DynamoDB Global Tables simplify building globally distributed applications by providing automatic, multi-region data replication. This example demonstrated how to set up a global table, insert and query data across regions, and monitor synchronization. By leveraging DynamoDB Global Tables, you can ensure low-latency access, high availability, and seamless scalability for your applications.