Boost Python UDP Server Performance with Eventlet and Gevent: A Real‑World Case Study

At first glance many dismiss Python as slow, but the language was designed for rapid development and can be optimized for performance-critical scenarios.

The author, a backend developer, describes a component (named "M") that runs a multithreaded UDP server to collect business metrics. Under load testing, CPU usage spiked to 100% with 2000 concurrent requests, causing alerts.

Attempts to improve performance by switching to a multiprocess model lowered CPU to around 70%, but the author sought a more efficient solution.

By adopting coroutine frameworks—Eventlet and Gevent—the single‑process server reduced context‑switch overhead and lock contention. Eventlet’s green threads and Gevent’s libev‑based micro‑threads provide lightweight concurrency.

An example using a Unix domain socket (UDS) demonstrates a pool that limits resources; each incoming request is handled by spawn_n in its own coroutine, and I/O calls are greenified to yield CPU when no data is available.

The official Gevent example shows how the monkey patch can convert standard threading code to greenlets, leveraging epoll and other optimizations.

Testing revealed that both Eventlet (UDS) and Gevent (UDP server) kept CPU usage around 30% at 2000 concurrent connections—a two‑thirds reduction compared to the original implementation, though further improvements (e.g., logging strategies) are planned.

References: https://github.com/gevent/gevent http://xlambda.com/gevent-tutorial/ https://github.com/eventlet/eventlet/tree/master/examples