Varnish Reference
HTTP accelerator and caching reverse proxy that serves cached content from memory in sub-millisecond response times. Varnish uses VCL (Varnish Configuration Language), a domain-specific language that compiles to C for maximum performance.
When to Use
- Accelerating dynamic websites by caching responses in RAM
- Writing VCL rules for fine-grained cache control and routing
- Purging or banning cached content by URL or pattern
- Load balancing across multiple backend servers with health checks
- Implementing ESI (Edge Side Includes) for partial page caching
- Optimizing WordPress or CMS performance at the edge
Commands
| Command | Description |
|---|---|
intro |
Architecture overview, Varnish vs Nginx caching vs CDN comparison, installation |
vcl |
VCL configuration language, caching rules, backend setup, load balancing, grace mode |
operations |
CLI tools (varnishstat/varnishlog), purge and ban patterns, ESI, WordPress integration |
Requirements
- No external dependencies — outputs reference documentation only
- No API keys required