What is the CQRS (Command Query Responsibility Segregation) pattern, and how does it fit into microservices?
CQRS is a pattern that separates the read (query) operations from the write (command)
operations to optimize performance, scalability, and security in systems.
In microservices:
Follow :
- Command Side: The microservices handling writes (e.g., creating or updating data)
are responsible for applying business logic and persisting data.
- Query Side: The microservices handling reads have an optimized, often
denormalized, view of the data to provide faster responses.
Why it's useful:
- Improves scalability by allowing reads and writes to scale independently.
- Enables optimized storage for read-heavy operations, like using a NoSQL database
for reads and a relational DB for writes.
Example: In an E-commerce system, you might separate the Order Command Service
(handling order creation) from the Order Query Service (serving read-optimized views of
order data).