Redis vs Tarantool: What are the differences?

Introduction

Redis and Tarantool are both in-memory data storage systems that are widely used in web applications. While they share some similarities, they also have distinct differences that make them suitable for different use cases. Below, we highlight the key differences between Redis and Tarantool.

1. Data Model: Redis is a key-value store, where data is stored as simple key-value pairs. It supports a wide range of data structures, such as strings, lists, sets, and hashes, providing flexibility in data manipulation. On the other hand, Tarantool is a NoSQL database that supports multiple data models, including key-value, document, and relational. This allows Tarantool to handle complex data structures and relationships more efficiently.

2. Replication: Redis supports single-master, multiple-slave replication, where data is asynchronously replicated from the primary server to the secondary servers. This provides high availability but might have some data loss in case of failures. In contrast, Tarantool has synchronous master-slave replication, ensuring that all writes are replicated to the replicas before they are considered successful. This guarantees data consistency but might introduce some latency.

3. Programming Languages: Redis supports various client libraries, making it compatible with a wide range of programming languages, including but not limited to Python, Java, Ruby, and Node.js. Tarantool, on the other hand, has its own programming language called Lua, which is used to manipulate and query data. While it also provides support for other languages like Python and C++, it is primarily designed to work with Lua.

4. Durability: Redis does not guarantee durability by default since it primarily stores data in memory. However, it provides options to persist data on disk through logging or snapshots. Tarantool, on the other hand, ensures durability by writing all the changes to disk before considering them committed. This makes it suitable for applications where data persistence is critical.

5. Concurrency Control: Redis supports single-threaded execution and relies on multiple isolated instances and replication for concurrency. On the other hand, Tarantool is a multi-threaded system that supports concurrent execution of transactions and provides built-in ACID (Atomicity, Consistency, Isolation, Durability) guarantees. This makes Tarantool better suited for applications with high concurrency and strong consistency requirements.

6. Store Procedures and Triggers: Tarantool supports stored procedures and triggers, allowing developers to define and execute custom scripts directly on the server-side. This provides more flexibility in data manipulation and allows for complex business logic to be executed within the database itself. Redis, on the other hand, does not have built-in support for stored procedures and triggers, relying on client-side logic for data manipulation.

In Summary, Redis is a flexible key-value store with support for various data structures and programming languages, while Tarantool is a versatile NoSQL database with advanced features like multiple data models, synchronous replication, and stored procedures. The choice between Redis and Tarantool depends on the specific requirements of the application in terms of data complexity, data persistence, concurrency, and business logic execution.