Epoll

Definitions

1. A Linux I/O event notification mechanism that efficiently monitors thousands of file descriptors for readiness events. Unlike poll/select (which scan all descriptors every time), epoll only reports descriptors with events, scaling O(1) with the number of watched descriptors. The foundation of high-performance event loops (Node.js, nginx, Redis).

   In plain English: Linux's high-performance system for monitoring thousands of network connections at once without wasting CPU.

   Example: "nginx handles 10,000 concurrent connections efficiently because epoll only wakes it up for connections with actual data to read."

Related Terms

• Service Mesh
• Async
• Buffer
• Client
• io_uring
• Cgroups
• Namespace
• Multiplexing
• Network Interface
• Systemd
• Connection