What is a node in a distributed system?

A node in a distributed system is an individual machine or device (such as a computer, server, or virtual instance) that participates in the distributed system. Each node operates independently but collaborates with other nodes to achieve a common goal, such as processing data, storing information, or executing tasks.

Characteristics of a Node

1. Autonomous Operation: Each node can function independently, running its own processes and tasks.
2. Communication: Nodes interact with each other via a network to share data, coordinate actions, or complete distributed tasks.
3. Roles: Nodes can serve different roles, such as clients, servers, or both, depending on the system's architecture.

Types of Nodes

1. Client Node: Requests services or resources from other nodes.
2. Server Node: Provides services or resources to other nodes.
3. Peer Node: Acts as both a client and a server in peer-to-peer systems.
4. Storage Node: Specializes in storing data in distributed storage systems.
5. Compute Node: Handles computational tasks in distributed processing systems.

Example of Nodes in Distributed Systems

• In Hadoop: Nodes are categorized as master nodes (e.g., NameNode) and worker nodes (e.g., DataNodes).
• In Blockchain: Each node stores a copy of the blockchain ledger and validates transactions.
• In Web Applications: Nodes can include load balancers, web servers, and database servers.

Importance of Nodes

• Scalability: More nodes can be added to handle larger workloads.
• Fault Tolerance: Redundancy across nodes ensures system reliability.
• Resource Sharing: Nodes collectively share and utilize resources to improve efficiency.

Nodes are the building blocks of distributed systems, working collaboratively to deliver functionality, reliability, and scalability.