Redis

General usage

Redis (short for ‘Remote Dictionary Server’) has built a reputation for its superfast sub-millisecond response times. As an in-memory database it serves queries from computer memory (RAM), rather than the disk drive, so data can be accessed quicker and requires less processing. 

This speediness has made Redis very useful for real-time applications like online gaming, stock trading, and media streaming that need to handle millions of requests per second.  

Redis supports a wide range of data structures:

• Bitmaps for images
• Text or binary data
• Data lists that can be used for message queues
• Hashes (field-value lists) used for authentication and validation 
• HyperLogLogs, a probabilistic data structure for fast accurate estimates used in big data and real-time analytics 
• Streams, a log data structure for message queues and chat systems
• Geospatial data structure for location-based apps, such as ride-sharing 

Due to its use of in-memory data storage, Redis can be used as a cache to take pressure off your primary database. This is especially useful for frequently requested data in read-heavy applications like social networks or CPU-intensive applications like the recommendation features used by Netflix, YouTube or Tinder.

As a message broker, Redis is mostly used for small transient messages. Message systems that require complex routings or extensive durability are better off with a dedicated message broker like RabbitMQ.

Popularity

Redis has been voted the most loved database for five years in a row (2017 – 2021) in the Stack Overflow Developer Survey. In 2021 it was ranked the second most popular NoSQL database after MongoDB and fourth most popular overall database solution by ranking website StackShare. 

Marketplace benefits

We used Redis to build a sophisticated business intelligence tool for Trelleborg, a global engineering group. Its ability to cache large volumes of data and flexible data structures helped to deliver a smooth user experience and ensured productive use of the tool. 

Image-heavy marketplaces like Airbnb use Redis as an in-memory database to reduce latency, while ride-hailing app, Uber, uses it for both caching and queuing to handle large amounts of real-time requests.