Event sourcing

This repository provides tools to implement event sourcing in your application.

It guaranties that:

• Events will be written in the database before being published in Kafka
• Publication in Kafka will be reattempted until it succeeds

It provides capabilities of defining two types of projections:

• "Transactional" projections, that are updated in the same transaction as the events
• "Eventually consistent" projections, updated asynchronously by consuming Kafka

It also allows storing snapshots of the application state, for scenarios that implies lot of events.

These libs are based on :

• Vavr for functional stuff (immutable List, Either, Future)
• Akka stream for reactive streams
• jackson for json
• jooq to build query
• vertx for reactive postgresql database access
• Postgresql and kafka are the in production tested data stores

Modules

• commons-event: POJOs that represent the stored events. Can be used by consumers to parse events.
• thoth-core: APIs for event-sourcing
• thoth-jooq: A jooq simple implementation of the thoth-core APIs
• thoth-jooq-async: A jooq implementation of the thoth-core APIs using the jooq-async-apiinterface

Documentation

See our documentation.

Limits

• A single command can't currently modify multiple entities see this issue

Development

Compile / Test

./gradlew compileJava

docker-compose -f docker-compose.test.yml up 
./gradlew test

Generate the documentation

cd thoth-documentation
sbt generateDoc