Custom VCL | Fastly Documentation

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Streaming logs
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Enhance your UX with Compute
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Geolocation at the edge
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Clustering in VCL

In normal operation, a request directed to a Fastly POP will be handled by two separate cache servers acting together in a process we call…

Getting started with VCL

Customize your content delivery.

Fastly’s Edge Cloud services use the Fastly Varnish Configuration Language (VCL), a scripting language used to configure and add logic to…

Synthetic errors in VCL

If a fatal error occurs in your service while processing your VCL logic, Fastly will generate an error response with a 503 HTTP status…

Uploading custom VCL

Fastly allows you create your own Varnish Configuration Language (VCL) files with specialized configurations. By uploading custom VCL files…

Fastly VCL is a domain specific programming language which has evolved from the Varnish proxy cache , which is part of Fastly's platform…

These articles describe VCL Snippets and how to use them.

VCL best practices

Best practices in Fastly VCL have changed over time to help address expectation gaps and improve maintainability. This page covers some of…

VCL regular expression cheat sheet

Fastly VCL uses a subset of Perl Compatible Regular Expression (PCRE) syntax. This is case sensitive and forward slashes don't need to be…

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