Resilient Message-Driven Systems with Ecotone Framework

Objectives

• To provide a simple example of how to implement Domain Driven Design and Messaging Architecture in PHP.
• To show how to implement CQRS, Event Sourcing and Hexagonal Architecture in PHP.
• To show how to implement Resilient and Observable Microservices in PHP.

About

It does not really matter if we work in E-Commerce, ERP or Finance based systems, we can be sure that system will be resilient, observable and maintainable in long term.
And we can achieve using principles of Message-Driven Systems combined with Domain Driven Design using patterns like CQRS, Event Sourcing and Service Bus in PHP.
And to make it happen we will use Ecotone Framework combined with Symfony or Laravel.

What is Ecotone

Ecotone is Message-Driven Framework for building resilient, business oriented systems in PHP. Ecotone allows to build Microservices and Event-Driven systems in PHP with ease.
Thanks to foundation build around Message Driven Architecture, it allows to build Resilient and Observable systems in PHP.
On top of that it provides patterns from DDD like - Aggregates, Domain Events, Projections, Sagas, and more. Ecotone integrates with Symfony and Laravel and allows you to connect Services seamlessly using Microservice or Event-Driven architecture.

In short Ecotone is a powerhouse to build reliable systems in PHP in a way that is maintainable, scalable and most importantly resilient.

Playing with the demo

Run docker-compose up -d to start all services.

Go to Customer Service to report issue as a customer.
Whenever issue is reported, confirming email will be sent to the customer, which can be found Mailbox.
First time email is sent it's set up for failing, so you can get feeling of working with system that can recover from error messages using Ecotone Pulse.
From Backoffice Service you may start working on ticket, that was correlated with issue reported by customer.
You may also check Jaeger to get full overview of how communication looks like and how each component behave and what is happening.

Stack

• Ecotone - PHP Framework for building resilient, business oriented system in PHP
• Symfony - PHP Framework for building web applications
• Laravel - PHP Framework for building web applications
• RabbitMQ - Message Broker for asynchronous communication
• Ecotone Pulse - Monitor for any processing errors and recover from failed messages.
• OpenTelemetry with Jaeger - Distributed Tracing for monitoring and troubleshooting microservices-based distributed systems

Business Domain

Customer Service

• Customer Service is Laravel+Ecotone application, where customers can report issues. This happens using CQRS combined with Eloquent Models.

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• Whenever new issue is reported, email is send to the with confirmation. This happens using Asynchronous Event Handlers, which are backed by RabbitMQ.

Backoffice Service

• Backoffice Service is Symfony+Ecotone application, where employees can be registered and work on the tickets.
  All issues reported by customers are synchronized to Backoffice Service and are correlated with tickets.
  The synchronization between Customer Service and Backoffice Service is done using Events and Distributed Bus for cross service communication via RabbitMQ.

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• Employees can work on the tickets provides information about the status. As we want to know full history, Tickets are Event-Sourced.
  From Event Sourced tickets we build different Read Model Projections, which are used to display information about the ticket.

Tracing and Monitoring

• The whole communication between Services is monitored and traced using OpenTelemetry with Jaeger.
  

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• Any issue that happens in the system is reported to Ecotone Pulse, which is used to recover from failed messages.