# Distributed Bus ## The Problem Service A publishes `OrderWasPlaced`. Service B needs to react to it. Today you POST it over HTTP — and when B is down, A times out too. You've already written serialization glue, custom retry middleware, and routing tables for three service pairs, and adding a fourth feels like another week of plumbing. ## How Ecotone Solves It A **Distributed Bus** is a [Message Gateway](/messaging/messaging-concepts/messaging-gateway.md) like CommandBus or EventBus, but the destination is *another service* instead of a local handler. You publish or send the same way you do locally; Ecotone routes the message across your existing broker (RabbitMQ, Kafka, SQS, Redis, Symfony Messenger, Laravel Queues) without per-pair configuration. Read more in the relevant module section. ## Support To find out more, read section related to specific implementation of Distributed Bus: * [Distributed Bus with Service Map](/modelling/microservices-php/distributed-bus/distributed-bus-with-service-map.md) - Works with (RabbitMQ, Amazon SQS, Redis, Dbal, Kafka, Symfony Message Channels, Laravel Queues) * [RabbitMQ Distributed Bus](/modelling/microservices-php/distributed-bus/amqp-distributed-bus-rabbitmq.md) - Works with RabbitMQ only --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.ecotone.tech/modelling/microservices-php/distributed-bus.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.