From Single Servers to Microservices: Evolution of Web Architecture

Technology originates from humanity, and like personal growth, website system architecture continuously evolves.

Single-Machine Architecture

In the era before 2004, many sites ran on PC servers—personal desktops used as servers. Companies such as Yahoo, Sina, and Livedoor operated thousands of FreeBSD PC servers that handled thousands of concurrent users without rebooting for a year.

These machines served roles like DB, Samba, FTP, and ran Apache, Nginx, MySQL, Perl/CGI, PHP, and JavaEE locally.

Multi-Machine Architecture

When traffic grew, a separate database server became necessary, leading to a web server plus a DB server configuration.

Further load on the database prompted multi‑machine setups, e.g., one master and one slave DB, or multiple masters and slaves to distribute read/write load.

Business Splitting

As traffic increases, servers are split by business domains—main site, news, forum, membership, orders, operations, customer service—often sharing sessions via common SSO or OAuth mechanisms.

Application Splitting

Each business function extracts its own codebase, enabling hierarchical code management and avoiding redundant deployments.

Distributed Cache

To reduce database pressure, frequently accessed data is cached using distributed solutions such as Varnish, Memcache, or Redis.

Database Sharding

Growing data volumes require sharding and possibly NoSQL solutions; search features may need dedicated search middleware.

Using CDN

CDNs act as large‑scale distributed caches, placing static content on many nodes worldwide, directing users to the nearest node via intelligent DNS, thus improving access speed and offloading traffic.

Load Balancing

Before 2008, hardware load balancers (F5, Netscaler) were common but costly. Modern software load balancing uses LVS, HAProxy, and Keepalived, offering easier scaling and lower cost.

Server Cluster

Horizontal scaling clusters, combined with load balancing, provide high‑traffic support while avoiding single‑point failures.

Service‑Oriented Architecture

Service‑oriented design (SOA) turns a website into a distributed system with API‑based interactions, allowing heterogeneous languages and paving the way for microservices.

Conclusion

This brief history outlines the evolution of website system architecture, setting the stage for deeper practice, case studies, and the underlying architectural and operational principles.