Jenkins Architecture – Overview
This section introduces the core architectural concepts of Jenkins.
Understanding this is mandatory before learning pipelines, shared libraries, or cloud setups.
What Is Jenkins Architecture?
Jenkins follows a distributed, controller-driven architecture designed to:
- Scale builds horizontally
- Isolate workloads
- Support multiple platforms (Linux, Windows, macOS)
- Handle parallel and concurrent executions safely
At a high level, Jenkins is composed of:
- A Controller (formerly Master)
- One or more Agents (formerly Slaves)
Terminology (Important)
| Legacy Term | Current Term |
|---|---|
| Master | Controller |
| Slave | Agent / Node |
Both terms are still used in interviews and real projects. You must know both.
Why Distributed Architecture?
Running everything on a single machine leads to:
- Performance bottlenecks
- Resource exhaustion
- Unstable Jenkins instances
Distributed architecture solves this by:
- Keeping the controller lightweight
- Offloading execution to agents
- Allowing parallelism and scalability
Core Architectural Components
You will study each of these in detail in this section:
- Controller
- Agent (Node)
- Executors
- Workspace
- Queue
- Distributed build execution flow
Each component has a dedicated document in this folder.