What protocols are used for data exchange between services in distributed systems?

Various protocols are used for data exchange between services in distributed systems, depending on requirements for performance, reliability, and data format. The main ones are:

• HTTP/HTTPS — the most common protocol, often used with REST API.
• gRPC — a high-performance protocol based on HTTP/2 with support for binary serialization (Protocol Buffers).
• AMQP — a messaging protocol often used with message brokers (e.g., RabbitMQ).
• MQTT — a lightweight messaging protocol, often used in IoT.
• WebSocket — a protocol for two-way real-time communication.
• Thrift — an RPC framework with its own serialization protocol.

The choice of protocol depends on specific tasks: synchronous or asynchronous exchange, requirements for speed, data volume, and support for various programming languages.