What are the main functions of message brokers, and what are they used for?

Message brokers are intermediaries that facilitate the transfer of messages between different components or services in distributed systems. The main functions of message brokers:

• Message buffering: temporarily store messages if the recipient is not ready to receive them.
• Asynchronous communication: the sender and receiver do not need to operate simultaneously.
• Message routing: direct messages to the appropriate recipients according to specific rules.
• Delivery guarantees: ensure reliable message delivery, including retries.
• Scalability: help distribute the load among multiple consumers.

They are used for microservice integration, implementing event-driven architectures, increasing fault tolerance, and simplifying system interactions.