DynamoDB Replication: Easy Step-by-Step Guide

Cloud Computing is no longer seen as an industry buzzword but as a critical next step for companies and organizations that seek to modernize their IT infrastructure. It is the solution for many startups that want a way to abstract away the complexities of large infrastructure while taking advantage of the scalability that cloud provides. The database powering the application needs to distribute data such that requests are served by databases in locations close to users, and one way of handling a distributed database is by performing Multi-Master Replication.

The present article aims at providing a step-by-step guide to help you set up DynamoDB Replication and help you replicate your DynamoDB data with ease. A complete walkthrough of the content will help you develop the skill to set up DynamoDB Replication to power distributed application architectures.

Table of Contents

• Introduction to DynamoDB
• Introduction to Replication
• Setting up DynamoDB Replication using Global Tables
  • Understanding DynamoDB Global Tables
  • Using the AWS Console to set up Multi-Region Replication in DynamoDB
• Conclusion

Introduction to DynamoDB

Amazon DynamoDB is a Cloud database service by Amazon, available as a part of the Amazon Web Services (AWS). It is a proprietary, fully-managed NoSQL database that supports both key-value and document-based database paradigms. The end-user need not worry about installing or managing the database, security patches, upgrades, etc. Amazon further guarantees high availability of the database, as a part of its Service Level Agreement (SLA) where certain aspects of its offering have a monthly uptime percentage guarantee of 99.99%.

Amazon DynamoDB employs a schemaless approach, allowing items in a table to have a different set of attributes, however, there is still a concept of a primary key for each item in a table. Amazon DynamoDB uses composite keys, consisting of the primary key and the sort key.

Amazon DynamoDB is tightly coupled to the Amazon Web Services ecosystem and can be used in synergy with other AWS services to create highly performant serverless web applications, mobile backends, microservices applications, etc. It is currently in use across a host of industries like banking and finance, gaming, retail, ad tech, etc., making sure that critical services are up and running all the time is a business prerogative.

Key features of using DynamoDB:

• Scalable: DynamoDB is a cloud offering and allows users to scale up or down depending on a spike in usage. It allows users to pay only for the resources they’ve used, thereby preventing them from investing in unused capacity because of a projected increase in demand.
• Managed: Amazon DynamoDB is a fully-managed service. Users need not spend time on activities like hardware provisioning, installation, configuration, software patching, managing servers, etc. This allows teams to concentrate on other aspects of application development.
• Secure: Amazon DynamoDB provides encryption at rest, thereby enabling users to protect their sensitive data conveniently without the additional burden of managing such a process in-house. It also provides an on-demand backup service so that databases can be stored periodically to support the long-term retention of data or to comply with regulatory authorities.

For further information on DynamoDB, you can check the official site here.

Introduction to Replication

Replication is the process of copying data from one database or server to another. It is usually done to ensure consistency between several computing resources (nodes) and to increase the availability and fault-tolerance of data. Some datasets may be out of sync with others as a result of replicating data from multiple sources at different times. This could be temporary, last for hours, or cause all data to become out of sync. Updates to replication can use a lot of processing power and cause the network to slow down. Automated Data Pipelines are used to overcome these challenges.

Automated Data Pipelines help resolve technical glitches due to malware, software errors, hardware failure, or other disruption, data access can still occur from a different site. Automated Data Pipelines like Hevo Data can efficiently carry out your data replication work.

The two methods of replication that are commonly used are as follows:

• Synchronous Replication: When a master node, receives a write transaction, it propagates the changes immediately to its replicas (standby servers) in a blocking fashion, ensuring that the data remains consistent across the main servers and replicas.
• Asynchronous Replication: The master node first commits write transactions and then propagates the changes to its replicas.

Replication can also be classified based on whether the write operations can be performed on a single server or multiple servers. These mechanisms are known as the Single Master and Multi-Master Replication. In the Single Master mechanism, write operations can be done only on the master server and all the slave servers carry out the read operations, whereas, in the Multi-Master mechanism, write operations can be carried on multiple servers.

Key features of Replication:

• Scalability: As the data volume increases the complexity of accessing data and working with data also increases. With replication in place, multiple data copies are available, allowing users to not only increase their data reserves but also recover any previous version in case of any errors or failures.
• Performance: When data is available across multiple machines and servers, it not only makes accessing data easier but also makes recovering from unexpected and sudden failures much easier. Replication ensures data availability and security at all times.
• Availability: With replication in place, there’s no need to worry about data failures. In situations where your primary source of data fails, you can easily access the same up-to-date data from a secondary reserve. This highly promotes data availability.

Prerequisites

• Working knowledge of DynamoDB.
• A DynamoDB account.
• Data stored in DynamoDB documents.

Setting up DynamoDB Replication using Global Tables

Amazon Web Services, the umbrella suite of products, has the concept of regions, which are the separate geographical areas that host Amazon’s computing resources.

Each region consists of numerous availability zones, which are a logical grouping of data centers. Using the multi-region architecture, you can leverage the Global Tables to set up DynamoDB Replication and replicate your data with ease.

Understanding DynamoDB Global Tables

DynamoDB Global Tables allows deploying a multi-region, multi-master DynamoDB replication solution. It is a fully-managed solution, where users need not write any custom code to make changes to data. DynamoDB automatically updates the data before replicating it across different regions. Global Tables are ideal for applications that have a global user base. It serves customers depending upon their proximity to a particular region, thereby lowering latency and improving the performance of applications. It also utilizes a multi-master paradigm so that write/reads are carried out across a large swathe of geographical locations.

Currently, there are two versions of DynamoDB Global Tables, Version 2019.11.21 (Current) and Version 2017.11.29. It is recommended to go with Version 2019 for all new implementations as it supports features such as the ability to add new replica tables even when the table is already populated (not empty). Version 2019 is more efficient and consumes lower write capacity, which results in fewer bills to pay.

For further information on Global Tables in DynamoDB, you can check the official documentation here.

Using the AWS Console to set up Multi-Region Replication in DynamoDB

Global Tables rely on DynamoDB streams to propagate changes between replicas. DynamoDB Streams are a mechanism for the flow of information about item changes in a DynamoDB table. Multi-Region DynamoDB Replication can be set up using various ways such as using the AWS Console, Amazon Command-Line, and Java to create Global Tables. In this method, you will be using the AWS Console to create the Global Tables. If you want to use the Amazon Command-Line or Java to create the Global Tables, you can check the official documentation here.

Use the following steps to create Global Tables using the AWS Console and set up Multi-Region DynamoDB Replication:

• Step 1: Creating Global Tables using the AWS Console
• Step 2: Adding Regions to set up DynamoDB Replication

Step 1: Creating Global Tables using the AWS Console

Launch the DynamoDB Console on your system and log in to your account using your credentials such as username and password. Once you’ve logged in, select the tables option from the panel on the left.

Click on the create table option and provide a name for your table. You need to select a primary key for your table to facilitate accessing data.
Select the global streams option from the menu bar on the top of your screen. Click on the enable streams option and set the view type as default.

Step 2: Adding Regions to set up DynamoDB Replication

Once you’ve enabled global streams, you now need to select a region. Click on the add a region button.

Once you’ve chosen the region, the AWS Console will check, whether the table you’re working with, exists in that region or not. In case a table with the same name exists, you must delete the existing table and then create a new replica for that region as follows:

Click on the create replica table option to start the process of Multi-Region DynamoDB Replication. You can add more regions, by again clicking on the Global Tables tab and repeating the same process.

This is how you can set up Multi-Region DynamoDB Replication using Global Tables.

Conclusion

This article teaches you how to set up DynamoDB Replication with ease and answers all your queries regarding it. It provides a brief introduction of various concepts related to it & helps the users understand them better and use them to perform data replication & recovery in the most efficient way possible. While you can use the Global Tables method to set up DynamoDB replication as described in this post, it is quite effort-intensive and requires in-depth technical expertise.

Hevo Data provides an Automated No-code Data Pipeline that empowers you to overcome the above-mentioned limitations. Hevo has native integration with DynamoDB and can seamlessly perform secure and consistent data replication in real-time within minutes from over 100+ data sources, apart from DynamoDB.

Learn more about Hevo

Want to take Hevo for a spin? Sign Up here for a 14-day free trial! Simplify Data Replication and Integration process with Hevo. Check out our unbeatable pricing to help you choose the right plan for your data needs.

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