Redis vs Riak: What are the differences?

Introduction

Redis and Riak are both NoSQL databases that are highly scalable and provide high availability. However, they have several key differences that set them apart from each other.

1. Data Model: Redis is primarily a key-value store where the value can be a variety of data structures such as strings, hashes, lists, sets, and sorted sets. Riak, on the other hand, is a document-oriented database that stores JSON documents.

2. Consistency and Availability: Redis is designed to prioritize consistency and availability, allowing for strong consistency and high availability. Riak, on the other hand, prioritizes availability over consistency, offering only eventual consistency and extreme availability.

3. Data Replication: Redis supports both master-slave and master-master replication, where data can be replicated to multiple nodes for improved availability and performance. Riak, on the other hand, uses a multi-master replication model, allowing all nodes to accept writes and propagate updates across the cluster in a decentralized manner.

4. Partition Tolerance: Redis relies on a single server node for both reads and writes, making it less tolerant to network partitioning. Riak, on the other hand, has built-in partition tolerance, allowing it to continue functioning even in the presence of network partitions and node failures.

5. Querying and Secondary Indexing: Redis provides limited querying capabilities but does not support secondary indexing out of the box. Riak, on the other hand, provides a powerful querying language and supports secondary indexing, allowing for more complex and flexible data retrieval.

6. Data Durability: Redis, by default, does not guarantee persistence, and data can be lost in the event of a crash or power failure. Riak, on the other hand, offers configurable durability options, allowing data to be written to disk or stored in multiple replicas to ensure its safety.

Summary

Redis and Riak differ in their data models, consistency and availability guarantees, data replication methods, partition tolerance, querying capabilities, and data durability.