Tapahtumalähetys

Tapahtumalähetys, often translated as event broadcasting or event streaming, refers to a software design pattern where applications communicate by sending and receiving events. Instead of direct, synchronous calls between services, one service publishes an event when something significant happens, and other interested services subscribe to these events and react accordingly. This decouples services, making them more independent and resilient.

In this model, an event can represent anything from a user signing up, an order being placed, or a sensor reading changing. The publisher doesn't need to know who or how many subscribers will receive the event. Subscribers, in turn, can process the event in their own time and independently of the publisher. This asynchronous communication is a key characteristic of tapahtumalähetys.

Common implementations of tapahtumalähetys involve message queues or event streaming platforms like Apache Kafka or RabbitMQ. These technologies act as intermediaries, reliably storing and delivering events to subscribed consumers. The benefits include improved scalability, as new services can easily be added to consume events without modifying existing publishers, and enhanced fault tolerance, as the failure of one service doesn't necessarily bring down others. This pattern is fundamental in building modern, distributed, and event-driven architectures.