This article compares three popular open‑source proxy servers—Nginx, HAProxy, and Varnish—detailing their performance, features, and ideal use‑cases, helping ops and network engineers decide which solution best fits high‑availability, high‑concurrency environments while considering maintenance overhead and resource consumption.
This article explains Varnish's caching mechanism, architecture, VCL configuration, request handling, load‑balancing setup, and static‑dynamic separation techniques, providing practical examples and diagrams to help reduce backend load and improve user experience.
This guide details a complete high‑availability architecture that separates static and dynamic DiscuzX traffic using HAProxy, adds Varnish caching, configures Nginx with NFS shares, sets up keepalived for HA, and provides all necessary installation commands, configuration snippets, and testing results.
This article provides a comprehensive overview of Varnish, covering its high‑performance caching architecture, core processes, built‑in VCL functions, variable usage across request handling stages, and practical configuration examples for optimizing web server response speed.
Varnish is a high‑performance open‑source reverse proxy and HTTP cache that stores data in memory for faster retrieval, using a master process to manage child workers that handle requests, allocate, serve, and evict cached objects based on LRU policies.
Varnish and Squid are open‑source reverse proxy cache servers, but Varnish generally outperforms Squid with higher stability, faster memory‑based caching, greater concurrent connections, and regex‑based cache invalidation, while its higher CPU, I/O, and memory usage and loss of cache on failure can be drawbacks.
This article explains what web caching is, how cache hit rates are measured, the request‑processing flow, freshness‑checking methods and cache‑control directives, then introduces Varnish as a high‑performance HTTP reverse‑proxy, detailing its threads, state machines, VCL syntax, installation, configuration examples and cache‑purge techniques.
Varnish is a high‑performance open‑source reverse proxy and HTTP accelerator that outperforms Squid through in‑memory caching, multi‑process architecture, and flexible VCL scripting; this guide covers its advantages, disadvantages, configuration, VCL syntax changes, request handling flow, and practical deployment examples.
This article provides a comprehensive, hands‑on tutorial for installing Varnish on CentOS, configuring its caching behavior with VCL, and customizing backend definitions, complete with command‑line examples and a detailed explanation of each VCL function.
