Schema Registry in Streaming

1. Introduction

In distributed streaming platforms, data is continuously generated, processed, and consumed. A schema registry serves as a central repository for schemas, ensuring that producers and consumers of data can understand the structure of the data they exchange.

2. Key Concepts

• **Schema**: A blueprint defining the structure of data (fields, types).
• **Serialization**: The process of converting data into a format that can be easily stored or transmitted.
• **Compatibility**: Rules that determine how schemas can evolve without breaking consumers.

3. What is a Schema Registry?

A schema registry is a service that stores the schemas used by producers and consumers of data in a distributed streaming system. By centralizing schema definitions, it facilitates schema evolution and ensures compatibility.

4. Use Cases

• Ensuring data compatibility across different versions of producers and consumers.
• Facilitating schema evolution without data loss.
• Validating data before it's sent to consumers.

5. Implementation Steps

To implement a schema registry, follow these steps:

1. Choose a schema registry implementation (e.g., Confluent Schema Registry).
2. Define your schemas using popular formats like Avro, JSON Schema, or Protobuf.
3. Register schemas in the schema registry.
4. Update producers and consumers to use the schema registry for schema retrieval and validation.

POST /subjects/{subject}/versions
{
  "schema": "{\"type\":\"record\",\"name\":\"User\",\"fields\":[{\"name\":\"name\",\"type\":\"string\"},{\"name\":\"age\",\"type\":\"int\"}]}"
}
                

6. Best Practices

• Regularly review and update schemas to accommodate changing data needs.
• Implement strict compatibility checks to avoid breaking changes.
• Document schema changes and their impact on consumers.

7. FAQ