Google Cloud Spanner vs Vitess: What are the differences?

Introduction

Google Cloud Spanner and Vitess are both popular database technologies that are used for scaling and managing large amounts of data. While they serve similar purposes, there are several key differences between the two.

1. Scalability: Google Cloud Spanner is a globally distributed horizontally scalable relational database service, designed to scale to massive amounts of data across multiple regions. It offers linear scalability and can handle high read and write throughput. On the other hand, Vitess is a sharding middleware for MySQL databases, which enables horizontal scalability by dividing large databases into smaller, more manageable chunks called shards. It provides automatic sharding and resharding capabilities, allowing for elastic scaling of the database.

2. Consistency Model: Cloud Spanner provides strong consistency guarantees across global transactions. It ensures that all reads see the most recent committed state of the data, regardless of the location of the read. Vitess, on the other hand, implements a more flexible consistency model called "semi-synchronous replication." It allows for asynchronous replication between shards, meaning there might be a slight delay in reading the most up-to-date data across all shards.

3. Storage Model: Cloud Spanner uses a storage model based on external storage that provides horizontal scalability and fault tolerance. It stores data in split tablets across nodes, where each tablet contains a range of keys. Vitess, on the other hand, relies on the underlying storage engine of the MySQL database it is deployed on. It does not introduce a new storage model but rather provides sharding capabilities on top of existing MySQL storage engines.

4. Querying Language: Cloud Spanner supports SQL query language, making it easy to interact with using familiar SQL syntax. It also supports distributed SQL queries that can span across multiple regions. Vitess, on the other hand, primarily provides compatibility with MySQL, which means it uses the MySQL query language for querying and managing data.

5. Transaction Management: Cloud Spanner offers distributed transactions with ACID guarantees across globally distributed data. It allows for strongly consistent reads and writes across multiple regions. Vitess, on the other hand, does not provide distributed transaction support out of the box. It relies on the transactional capabilities of the underlying MySQL storage engine and does not support distributed transactions.

6. Use Cases: Cloud Spanner is suitable for use cases that require global scalability, strong consistency, and support for transactional operations. It is often used for large-scale, globally distributed applications that need a horizontally scalable relational database. Vitess, on the other hand, is primarily used for scaling MySQL databases in a cloud-native environment. It is well-suited for sharding large databases, providing elasticity, and enabling horizontal scalability.

In summary, Google Cloud Spanner is a globally distributed horizontally scalable relational database with strong consistency and ACID transactions, whereas Vitess is a sharding middleware for MySQL databases that enables horizontal scalability using sharding techniques and is suitable for cloud-native environments.