Skip to main content

Moleculer Microservices Framework

Moleculer is a fast, powerful, and flexible microservices framework. Its core philosophy revolves around building applications by decomposing them into services. Each service is autonomous, allowing for independent deployment, scaling, and maintenance. Moleculer provides a lightweight messaging system, simplifying and optimizing communication between services.

Basic Architecture​

The foundational architecture of Moleculer consists of several main components:

  • Services: This represents the cornerstone of the Moleculer architecture. Each service signifies an independent functional unit, deployable, scalable, and updatable in isolation.
  • Transporters: Responsible for conveying messages between various services or nodes. Moleculer supports numerous transport protocols such as NATS, MQTT, and AMQP, making it easily integrable into diverse environments.
  • Nodes: A node represents a computational instance running one or more services. Nodes communicate with each other through transporters.
  • Service Brokers: Service brokers offer a unified interface for each service, facilitating easy communication and interoperability.

Service Lifecycle​

Within Moleculer, each service experiences its lifecycle, encompassing the following primary stages:

  • Creation: When a service initially starts up, it enters the creation phase. During this stage, the service initializes and prepares to process requests.
  • Start: Once the service is primed to accept requests, it transitions into the start phase. In this phase, the service can begin handling requests and responses.
  • Running: During the running phase, the service persistently processes requests until it's halted or restarted.
  • Stopping: When the service is no longer required to operate, it enters the stopping phase. Here, the service releases all resources and ceases to process new requests.

Nodes and Service Discovery​

Moleculer employs dynamic service discovery to automatically detect and connect to other nodes and services on the network. Here are its key features:

  • Dynamic Discovery: As new nodes or services join the network, Moleculer automatically identifies and establishes connections with them.
  • Health Checks: Moleculer routinely inspects all nodes and services to ascertain their activeness and proper functioning.
  • Load Balancing: Moleculer adopts an in-built load balancing strategy to ensure requests are evenly distributed across all available service instances.
  • Failover: Should a service instance fail, Moleculer automatically redirects requests to other functioning instances, guaranteeing high availability.