How is communication between individual microservices implemented in the system architecture?

Communication between microservices in a system architecture is usually carried out using one of the following methods:

• HTTP/REST API — microservices exchange data via HTTP requests, using REST or other protocols over HTTP.

• gRPC — a high-performance remote procedure call protocol that uses Protocol Buffers for serialization.

• Messages through message brokers — asynchronous communication via queue systems such as RabbitMQ, Kafka, Redis Streams. This allows microservices to exchange events and data without direct calls to each other.

• WebSocket — for bidirectional real-time communication.

• Shared cache or database — a less preferred method, where microservices read and write to a common database, but this reduces independence.

Example of exchange via REST API:

# Service A sends a request to service B
import requests

response = requests.get("http://service-b/api/data")
data = response.json()

Asynchronous exchange via message broker:

# Publishing a message to RabbitMQ
import pika

connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()
channel.queue_declare(queue='task_queue')
channel.basic_publish(exchange='', routing_key='task_queue', body='Hello')
connection.close()

The choice of method depends on requirements for latency, reliability, and system complexity.