Architecture

CloudStack organizes infrastructure hierarchically. Each level serves a specific purpose. The Hierarchy Region (Geographically dispersed) └─ Zone (Usually = 1 datacenter) └─ Pod (Usually = 1 physical rack) └─ Cluster (Same hypervisor type) └─ Host (Individual physical computer) Regions Collection of zones across different locations. If one datacenter fails, other regions keep running. Visible to users: Yes Zones Typically one datacenter. Provides physical isolation (separate power, network). Contains pods and secondary storage....

A concise runtime map of Apache CloudStack modules showing which are core vs plugin, and how they depend on each other. Runtime Layer Map (top → bottom) ────────────────────────────────────────────── [ UI Layer ] → /ui/ (Vue.js frontend) ────────────────────────────────────────────── │ (calls REST APIs via /client/api) ▼ [ API Layer ] → /api/ ────────────────────────────────────────────── │ Defines: BaseCmd, BaseAsyncCmd, annotations, │ response objects, validation, and command dispatch ▼ [ Service / Manager Layer ] → /server/, /engine/, /services/ ────────────────────────────────────────────── │ Core business logic: │ - VmManager, NetworkManager, VolumeManager, etc....