Redis

vs

Apache Cassandra

Memcached is a free and open-source in-memory key-value store used for storing small chunks of data objects in dynamic memory. Most commonly, Memcached is used to speed up dynamic database-driven websites by caching data and objects in RAM to reduce the number of times an data sources needs to be fetched. Rather than querying the database for each unique request, Memcached can be used to store data from common pages in memory and speedup and improve the experience of a web application or website.

MongoDB is an open-source document-oriented distributed database built for modern applications. MongoDB uses JSON-like documents with optional schemas and is classified as a NoSQL database. The database is freely distributed under the Server Side Public License, but MongoDB provides commercial version of the database for enterprise-scale applications.

KeyDB is fast, free, and open-source NoSQL database with full compatibility for Redis APIs, clients, and modules. The database was originally forked from the Redis code-base and has been improved to handle multithreading, memory efficiency, and higher throughput. KeyDB is now a fully multithreaded and allow many machine cores to operate a single node resulting in 5X the throughput of Redis (v5) and up to 3x the throughput of Redis (v6). KeyDB also includes Redis Enterprise such as Active Replication, FLASH storage support, and other features like direct backup to AWS S3.

Cockroach is a distributed key/value datastore that allow you to build, scale and manage modern, data-intensive applications. The database delivers distributed SQL by combining the familiarity of relational data with limitless, elastic cloud scale and bulletproof resilience. Correct data is a must for mission-critical and even the most common applications. CockroachDB provides guaranteed ACID compliant transactions, allowing you to fully trust your data.

ArangoDB is a database system that was designed to support key/value, document, and graph data to be stored together, and queried via a unified language called AQL. The project is developed by ArangoDB GmbH, and released free and open-source under the Apache License 2.0. The universal "native multi-level" design of the database allows for a flexible approach when structuring and building an application, a feature that many have come to love.

MongoDB is an open-source document-oriented distributed database built for modern applications. MongoDB uses JSON-like documents with optional schemas and is classified as a NoSQL database. The database is freely distributed under the Server Side Public License, but MongoDB provides commercial version of the database for enterprise-scale applications.