DynamoDB Global Tables

DynamoDB Global Tables provide a fully managed solution to replicate data across multiple AWS Regions, with automatic conflict resolution. This increases the availability and durability of DynamoDB databases, and can also help to reduce response time for global applications.

Syntax

Global Tables are created using the AWS Management Console or the AWS Command Line Interface (CLI). The process involves configuring the regions, creating or selecting existing DynamoDB tables for replication, and setting up continuous replication.

Example

Assuming we have an existing DynamoDB table named users, we can create a Global Table using the AWS CLI with the following command:

aws dynamodb create-global-table \
    --global-table-name users-global \
    --replication-group RegionName=us-east-1 RegionName=us-west-2 \
    --region us-east-1

In the above example, we create a new Global Table named users-global, specifying us-east-1 and us-west-2 as the regions to replicate data. The command is run from us-east-1 region.

Output

Upon successful execution, the output will display the GlobalTableName, ReplicationGroup, and other details about the newly created Global Table.

Explanation

DynamoDB Global Tables work by replicating data from a table in one region to a table in another region(s) through continuous replication. Whenever data is updated, deleted, or inserted in the source table, the change is automatically propagated to all the destination tables in the different regions, ensuring that the data stays consistent across all regions.

Use

Global Tables are an ideal solution for serving globally distributed applications. With Global Tables, you can provide low-latency access to your application data from any region, thus making the user experience better.

Global Tables can also be used for disaster recovery by replicating your data across multiple regions. In case of a disaster, your data is safe and available in other regions.

Important Points

• Global Tables require DynamoDB Streams to be enabled on the source table.
• Global Tables are an additional feature, which requires extra charges.
• Automatic conflict resolution attempts to merge changes based on write timestamps, and if not possible, chooses the most recent change.

Summary

In this tutorial, we learned about DynamoDB Global Tables, which allow data replication across multiple AWS Regions, increasing availability and durability of DynamoDB databases, and reducing response time for global applications. We've seen how to create a Global Table using AWS CLI and use cases for Global Tables. Also, we learned about important points related to Global Tables and their additional charges.