In the context of computer science and software engineering, “publish/subscribe” (pub/sub) is a messaging pattern in which senders of messages (publishers) do not send messages directly to specific receivers (subscribers). Instead, subscribers register their interest in messages of a particular topic, and publishers distribute messages to all subscribers who are interested in that topic. This allows a decoupling of the sender and the receiver, as the sender does not need to know the identity of the receivers or have a direct connection to them.
Pub/sub systems can be implemented in a variety of ways, such as using message queues or event buses. They are commonly used in distributed systems and are often used to facilitate communication between microservices in a microservice architecture. Pub/sub systems can also be used to implement event-driven architectures, where events trigger actions in other parts of the system.
Here is an example of how pub/sub might work:
- A publisher creates a message and publishes it to a topic.
- The pub/sub system receives the message and stores it.
- Subscribers register their interest in the topic and receive a copy of the message.
- The subscribers can then act on the message as needed.
Pub/sub systems can provide a number of benefits, including decoupling of components, flexibility, and scalability. They can also allow for more efficient communication between components, as the publisher does not need to send a message to each subscriber individually.
