Cassandra vs Redis – What’s the Difference (Pros and Cons)

Cassandra vs Redis – What’s the Difference (Pros and Cons). In this article we will introduce what Cassandra and Redis server is with their pros and cons. Lets get started. 

Today, data is playing a crucial role in the innovation and growth of the business. Although relational databases are helping them to acquire the desired goal, some of the issues like data complexity, volume and demand to make specific applications inappropriate.

This issue enables businesses to shift their attention from conventional, structured platforms to NoSQL platforms, such as Redis and Cassandra. These two platforms are relatively popular in the business world. Please follow this blog to help you understand Cassandra vs Redis – What’s the Difference (Pros and Cons).

What is Cassandra

Apache Cassandra is a NoSQL distributed database management system built to manage large amounts of data in several data centers and the cloud. It is highly scalable, provides high availability and doesn’t have any single point of failure, making it primarily beneficial for a lot of corporations. It works on HiveQL syntax, which provides greater consistency. Currently, it is used by top businesses like Apple, Instagram, Uber, Spotify, Twitter, etc.

Cassandra Features

Apache Cassandra provides the following features to its users:

Distributed – Every node in the cluster provides you with similar features. This way, the system is not susceptible to failure and helps in distributing data sets all over the cluster.

Scalable – Cassandra is designed in a way that it can rewrite throughout and even increases with the addition of new machines without interrupting other applications.

MapReduce Support – It supports Hadoop integration along with MapReduce support.

Query Language – Cassandra supports CQL (Cassandra Query Language) that allows users to access it effortlessly.

Fault Tolerance – Cassandra by default stores data and replicates fault tolerance. Therefore, whenever a Cassandra node fails, it is replaced immediately.

Pros of Cassandra

Following are the reasons that make Cassandra a solid database management system:

  • It is an open source platform that uses peer to peer architecture instead of master slave architecture, thereby eliminating the point of failure.
  • It enables organizations to scale up and down effortlessly.
  • It is fault tolerant and has high availability as it features data replication.
  • Since it is schema free or optional, it allows you to create columns in the rows without showing all the columns required to run the application.
  • Designed as a distributed system that deploys multiple nodes across several data centers and even supports hybrid cloud environments.
  • It is a high performance database manager that handles a large amount of data quite effortlessly.

Cons of Cassandra

Cassandra also has some drawbacks that are given below:

  • It does not support ACID and relational data properties.
  • Since data is modeled around queries instead of structure, it stores similar information several times.
  • It does not offer join or subquery support.
  • From the beginning, Cassandra was designed to provide fast writing. However, the reading gets shorter at the end of the stick, making it slower.
  • Its ability to handle a large amount of data and requests slows down the transactions and causes latency issues.
  • You might also face the problem of JVM memory management due to the capability of managing a bulk of data.
  • It also does not support aggregates.
  • It does not have official documentation from Apache, which is why you have to seek it from third party companies.

What is Redis

Redis is a fast in memory database, an open source NoSQL data structure used as a cache, database and message broker.

Being a NoSQL advanced key value data store, it is often referred to as a data server structure. Its keys contain strings, hashes, lists, sets, sorted sets, bitmaps, etc. The reading and writing process in Redis server is very fast since it has the ability to store data in memory. It also allows you to store data in the disk or write it back to memory.

Businesses that enjoy the benefits of Redis are Twitter, GitHub, Instagram, Pinterest, and Snapchat.

Redis Features

Redis provides the following features to its users:

In Memory Datastore – Redis store all the data in the main memory of its server. This way, you can acquire faster response times and even provide your applications with faster performance and support for multiple operations, occurring per second.

Highly Available and Scalable – Redis provides a primary replica architecture within a single node primary or clustered topology. This way, you can build a highly available solution with consistent performance and reliability.

Provide Persistent Data – By Data Persistence, we are talking about the data that survives the producer process of the data. In short, Redis protects your data if server failure is encountered.

Simplicity – The languages supported by Redis are C, C++, and C#, Java, Javascript, Python, etc. Also, it has large open community support that enables you to be extensible on Redis. It is a simplified technology that requires very few lines to integrate with the applications.

Pros of Redis

  • Redis is very fast. It can perform 110,000 SETS and 81,000 GETS per second.
  • It receives updated information whenever two clients access data concurrently.
  • You can easily configure it in your system.
  • It is most efficiently used for caching, messaging queues and short lived data like web application sessions.
  • It supports several data types, including lists, sets, hashes, and sorted sets, which makes it highly flexible.

Cons of Redis

  • Since data is sharded based on the hash slots assigned to every Master, any failure in that slot will lead to loss of data.
  • Being an in memory database, it needs a huge RAM.
  • Master needs to have one slave to avoid failover.
  • You need to be aware of the Redis cluster’s topology, which leads to overhead configurations.
  • Mapped key value based Redis caching system.
  • Redis Cluster– a distributed implementation of Redis that automatically splits datasets among multiple nodes.
  • Redis Pub/Sub.

Cassandra vs Redis – What’s the Difference

Cassandra vs Redis

The primary difference between Cassandra and Redis are as follows:

Technology Types

Cassandra utilizes a broad column store as a primary database model, which serves as a two dimensional key value store. It enables the users to store vast databases quite effortlessly.

On the other hand, Redis has a key value store in the form of a primary database. This way, the tools are highly dynamic and even capable of handling multiple datasets. Users also use it as a message broker and queuing process.


Cassandra provides stability. Therefore, like SQL, it allows you to store vast datasets. However, it is relatively slower in comparison to Redis.

One problem users usually face with Redis is that it acts slowly when used for huge datasets. It is more suitable for rapidly changing datasets.


Cassandra focuses on two theorems, namely, CP (Consistency, Partition Tolerance) and CAP (Consistency, Availability, and Partition Tolerance). That is why it is more suitable for the financial services domain.

On the contrary, Redis uses AP (Availability and Partition Tolerance) and a part of CAP (Consistency, Availability, and Partition Tolerance) theorem, thereby being a most favorable tool for dynamically changing database solutions like data analytics and real time analytics.

Programming Languages

Since Cassandra works on Java programming, it is schema free and also uses thrift protocol for API fetching.

On the other hand, Redis works with C programming, is also schematic, and uses the telnet protocol for APIs and other recovery tactics.

Uses and Applications

Cassandra proves to be highly beneficial when you have distributed, linearly scalable, write oriented and democratic peer to peer databases or data structures. Therefore, it is highly efficient in transaction logging, health care data storage, telematics for automotive and weather services.

However, Redis is efficient for users using in memory data storage, vertically stable and read oriented data structure and dynamic database. Therefore, you can use it for session caching and you can also use it for read oriented and dynamic databases.

Real Life Examples

Many popular companies like Reddit, Constant Contact, Nutanix and Netflix use Cassandra for multiple reasons that include storage, email applications, Metadata storage, backend database and many more.

Redis is also relatively popular among top companies like Staples, Udemy, Inovonics, and Utilitywise for fast response, increasing reach with zero downtime, analytics and faster performance.

Cassandra vs Redis – What’s the Difference (Pros and Cons) Conclusion

Based on the differences and pros and cons of each of these tools, we can say that they are highly suitable according to the requirements of the business. Therefore, if your business is facing the issue of heavy databases then Cassandra is most beneficial to you. On the other hand, if your business is about reading, writing and analytics then Redis proves to be the most efficient tool for you.

Avatar for Hitesh Jethva
Hitesh Jethva

I am a fan of open source technology and have more than 10 years of experience working with Linux and Open Source technologies. I am one of the Linux technical writers for Cloud Infrastructure Services.

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