Events

Overviewing basics of event processing in Event-Driven Architectures:

• Typical structure of microservice
• Typical types of event transformations, 2 branching scenarios, merging streams
• Repartitioning events and when it can be useful
• Copartitioning events and when it is needed
• Assigning Partitions to a Consumer Instance. Three strategies to do this.
• Recovering from stateless processing instance failures.

These topics are disclosed in the Chapter 5 of the book we are currently studying:

“Building Event-Driven Microservices: Leveraging Organizational Data at Scale” by Adam Bellemare

The Event-Driven model heavily relies on the QUALITY of events.

Good quality events are:

• explicitly defined via contracts
• have comments
• support evolution with backward and forward compatibility
• support code generation
• breaking changes are well thought

Good events are implemented using the right tools:

• use Avro/Thrift/Protobuf formats and never use JSON!
• use the right event broker (such as Pulsar)

Good events are designed to:

• contain all the info needed by consumers
• use separate streams for each event type
• use the right data types for their fields (don’t use string for numbers, use enums, etc.)
• don’t use type field and fields based on it
• be as small as possible
• consider requirements from consumers
• not just signals - they contain all info needed by consumers

These topics are disclosed in the Chapter 3 of the book we are currently studying: