DynamoDB vs Redis - The Ultimate Comparison

DynamoDB and Redis are two popular NoSQL database solutions that support key-value pair data storage formats. This article will discuss the similarities and differences between these two to help you decide when to use which database service.

DynamoDB and Redis: An Overview

Amazon DynamDB is a reliable, scalable, and robust NoSQL database fully managed by AWS. It is capable of delivering single-digit millisecond performance on any scale. As a result, this database service is highly efficient for any web, mobile, or gaming applications that require low latency data access.

On the other hand, Redis (Remote Dictionary Server) is a fast, reliable, and open-source datastore famous for caching, session management, and real-time analytics. It supports a wide array of data structures, including Hashes, Strings, Bitmaps, Lists, Sets, and Sorted Sets. Furthermore, Redis uses the BSD license, which means you can freely use it for commercial purposes.

Shared Features of DynamoDB and Redis

DynamoDB and Redis are fast, robust, and reliable NoSQL databases. They both use the key-value store as the primary database model, and DynamoDB also supports the document model. Redis offers secondary database models like the document store, graph DBMS, and spatial DBMS.

The partitioning method is sharding in DynamoDB and Redis, and both are dependable and popular database solutions.

Latency and Performance of DynamoDB vs Redis

DynamoDB

DynamoDB is a powerful, high-performance, and highly available database service. DynamoDB can support more than 20 million requests per second and deal with more than 10 trillion requests per day.

The high IO performance of the SSDs enables DynamoDB to read and write data with minimum latency and response time regardless of the table size. Furthermore, you can optimize the performance by streamlining the database workload and properly using indexes and keys.

With the in-memory cache for DynamoDB (using DynamoDB Accelerator), you can boost the performance by ten times the original rate (from milliseconds to microseconds), even at million requests per second.

Redis

Redis is an ideal solution for building complicated data structures quickly because of its high speed as an in-memory database. It is easy to use and scalable. However, these high-speed operations require a significant amount of memory to process.

Redis can handle millions of requests per second and has a sub-millisecond response time. In addition, the performance is optimized with request scheduling and high-performance pipeline execution to provide maximum performance over all the data types and models.

Availability and Durability

DynamoDB

DynamoDB replicates every piece of data over three availability zones in an AWS region to ensure the data is highly available and durable. So even if one copy of the data is lost, there are two other up-to-date copies of the same data. And if one node is to fail temporarily under any circumstance, both read and write operations to the database can proceed without any flaw.

Redis

Redis Enterprise offers diskless replication, instant failure detection, and 99.999% uptime to ensure the high availability of data. In addition, Redis offers a high throughput and low latency even when there are software upgrades and cluster changes. However, Redis open-source is not precisely durable, but Redis Enterprise is fully durable with multiple persistence options.

Security

DynamoDB

DynamoDB uses the encryption keys stored in AWS KMS (AWS Key Management Service) to encrypt at rest all the data. The user can decide whether to use an AWS-owned key, AWS managed key, or a user-managed key for the encryption.

Apart from that, you can use IAM (Identity and Access Management) roles to authenticate access to DynamoDB. If the access is required only from within a VPC (Virtual Private Cloud), you can control and limit access using a VPC endpoint. In addition, there are libraries like the Amazon DynamoDB Encryption Client to secure the data even more.

Redis

Redis is not so secure by default and is prone to many malware and attacks. In addition, it does not provide access control, so it is not okay to expose the Redis instances directly to the internet.

But, it is possible to make your Redis instances secure using several methods such as:

1. Use the encryption features of the cloud service provider if possible.
2. Rename and reconfigure critical commands.
3. Manage user permissions.
4. Do not expose to the internet or non-trusted environments.

Other Features of DynamoDB and Redis

Backups

Regardless of the table size, DynamoDB offers an on-demand backup option to create a full backup of your DynamoDB table for long-time retention within seconds. In addition, PITR (Point-in-time Recovery) enables us to constantly back up the data automatically with per-second granularity to restore the data to any second within the preceding 35 days.

With Redis Enterprise, you can back up a snapshot of the database across all the shards to major public cloud storage solutions like Amazon S3 and Azure Blob Storage or FTP. Redis open-source also supports point-in-time backups that copy the data set to a disk.

Scalability

DynamoDB is a fast and predictable database, and its high scalability does not affect the overall performance. DynamoDB can seamlessly scale when the workloads go up and down and can support virtually any table size. Similarly, you can quickly scale Redis databases without any performance degradation or downtime, and it supports automatic sharding.

When and Where to Use Which Database Service

Use Cases for DynamoDB

Sometimes, using SQL databases may not seem the correct choice or cost too much. So, if you are looking for a NoSQL database service, especially if you are already using AWS services, then Amazon DynamoDB is the best choice.

It is fully managed by AWS, scalable without interruption, secure, and most database operations like backups are automated. With impressive performance rates, DynamoDB is ideal for applications that require high-speed data writing and reading.

We can use DynamoDB when auto-scaling, auto-sharding, low-latency, and high durability are required and when there is no size or throughput limit.

Use Cases for Redis

Redis is an excellent choice for session cache, chat, messaging, and queues. In addition, it is ideal for creating gaming leaderboards based on users' scores. And Redis is a popular choice for managing geospatial data, live streams, and real-time analytics.

Pricing

DynamoDB

Core features of DynamoDB (reading, writing, and storing data) account for the standard pricing of DynamoDB. But the charges vary depending on the additional services a user subscribes to. Users can select one out of the two pricing tiers given below.

1. On-demand capacity mode allows DynamoDB to scale the workload up and down based on the application traffic and requirements. It is a good choice if you want to pay only for what you use and when the database traffic is less predictable.
2. In Provisioned capacity mode, the user needs to specify the reads and writes required for the application. It is ideal when the application traffic is consistent and predictable.

Redis

Redis is free to use as it is open-source licensed. But several limitations make using the Redis Enterprise (cloud-hosted and on-premise) a better choice. Redis Enterprise offers better, uninterrupted performance, cluster recovery, and higher availability.

For Redis Enterprise, there is a free trial and three pricing tiers:

1. Fixed - 7$ per month
2. Flexible - 0.881$ per hour
3. Annual

Read More: Redis Enterprise Pricing

Conclusion

Redis and DynamoDB are both great databases. But you need to choose them based on the requirements, allocated budget, and the type of the project. I hope this article will help you to make your decision. Thank you for reading!