Web Server Tuning for High Traffic

When your site faces a spike in visitors, even small delays add up. Tuning helps you handle load more reliably and keeps users satisfied.

Start with measurement. Before changing anything, collect metrics: requests per second, latency, error rate, CPU and memory use, and the count of open file descriptors. This helps you spot bottlenecks.

Focus areas to tune

  • System limits: raise the number of open files and adjust process limits so the server can handle many connections.
  • Worker setup: choose the right number of worker processes and allow enough simultaneous connections.
  • Timeouts and keep-alive: set reasonable timeouts and enable keep-alive to reuse connections without wasting resources.
  • Caching and compression: enable gzip or brotli, cache static content, and set long cache headers for assets.
  • TLS and efficiency: reuse TLS sessions where possible; consider TLS 1.3 and session tickets to reduce handshakes.
  • Networking and buffers: tune receive/send buffers and backlog to handle burst traffic.

Practical tweaks

  • Nginx: set worker_processes to auto, worker_connections to around 1000, and keepalive_timeout to 65 seconds.
  • Apache: compare mpm_event or mpm_worker and adjust the number of child processes to match traffic; keep-alive on for static assets.

If you serve dynamic content, consider a CDN or edge cache for static parts to take load off the origin. Separate slow database queries from web requests and add a small in-memory cache for hot data.

Testing and monitoring

Regular load testing with tools like k6 or wrk helps validate changes. Monitor response times, error rates, and CPU use after each adjustment. Keep a baseline and a rollback plan in case a tweak goes wrong.

Bottom line: tuning is ongoing work. Start with big limits and sensible defaults, then refine based on real traffic and clear goals. A well-tuned server handles traffic spikes more smoothly and improves user experience.

Key Takeaways

  • Measure first, then adjust.
  • Tune for the workload, not the theory.
  • Monitor continuously and rollback when needed.