Eventuate application architecture

An Eventuate application consists of four types of modules, each with different roles and responsibilities.

The following diagram shows the architecture of an Eventuate application:

An Eventuate application consists of the following types of modules:

• Command-side module
• Query-side view updater module
• Query-side view query module module
• Outbound gateway module

Note that this is the logical architecture of the application. The modules can either be deployed together as a monolithic application or separately as standalone microservices.

Command-side modules

The command-side of an Eventuate application consists of one or more command-side modules. A command-side module creates and updates aggregates in response to external update requests (for example, HTTP POST, PUT, and DELETE requests) and events published by command-side aggregates. A command-side module consists of following components :

• Aggregates - Implement most of the business logic and are persisted using event sourcing
• Services - Process external requests by creating and updating aggregates
• Event handlers - Process events by creating and updating aggregates

Query-side modules

The query-side of an Eventuate application maintains one or more materialized (CQRS) views of command-side aggregates. Each view has two modules:

• View updater module - Subscribes to events and updates the view
• View query module - Handles query (for example, HTTP GET) requests by querying the view

Outbound gateway modules

An outbound gateway module processes events by invoking external services.