Event Sourcing & CQRS

Event Sourcing

• Event Sourcing is a design pattern where all changes to the application state are stored as a sequence of events

Event Sourcing ensures that all changes to application state are stored as a sequence of events.

Martin Fowler: Event Sourcing

• Storing a log of all events provides an "natural" audit trail (журнал аудита, контрольный журнал) (link)

• Partitioning PLog into PLogPartition provides horizontal scalability

CQRS

• CQRS (Command and Query Responsibility Segregation) is a design pattern where different data models are used for writes (by Commands) and reads (by Queries)

• Implementing CQRS in your application can maximize its performance, scalability, and security (CQRS pattern, learn.microsoft.com)

Event Sourcing + CQRS