Building scalable and efficient real-time applications often involves managing thousands of connections simultaneously. WebSockets, as a communication protocol, are designed to enable full-duplex communication channels over a single, long-lived connection. However, handling these connections, especially in high-load environments, is challenging. This is where epoll, a high-performance I/O event notification system in Linux, becomes essential for maintaining WebSocket connections with minimal overhead. In this article, we’ll dive into how epoll works in the context of WebSocket management, explore best practices, analyze relevant factors, and address the nuances of using epoll for maximum efficiency.