Location rules Yandex Cloud CDN

Location rules are a mechanism used to selectively redefine CDN resource settings for requests whose paths match a specific template.

Let’s assume that content caching is enabled in the CDN resource settings, while cache lifetime is set to four days. This is enough for most types of content, but for some specific files you have to reduce cache lifetime to a few seconds. Location rules will help you with such cases.

You can use location rules to override the following CDN resource settings:

• Origin group
• Content caching
• Request redirect
• Parameters of access via secure tokens
• IP-based access policy
• HTTP request and response headers
• Allowed HTTP methods for client requests
• Cross-domain CORS requests
• Content compression
• Content segmentation
• Non-standard HTTP responses

For each location rule, specify the following parameters:

• Regular expression: URI path pattern against which requests are checked. If there is a match, the settings specific to that location rule will apply.

  Tip

  To explicitly indicate the start or end of the string to match in a regular expression, use the ^ and $ anchor characters.

• Rule weight: Rule triggering priority. The lower a rule’s weight, the higher its priority in the user resource configuration. If multiple rules have the same weight, they will be applied in a random order.

  
  

  For example, let’s assume you set the following location rules:

  Rule	Weight	Regular expression	Cache lifetime
  A	1	^/path/.+	1 hour
  B	2	\.txt$	4 hours

  With this configuration, the /path/file.txt request will match rule A, which has a lower weight and a higher priority than rule B, so the file will be cached for one hour.

  To cache the /path/file.txt file for four hours, rule B must have a lower weight than rule A.

For the full list of location rule parameters, see the API specification.

You can configure location rules in the management console or using the API. For more information, see Setting up Yandex Cloud CDN location rules.

Useful linksUseful links

• CDN resource
• Content caching
• Request redirection
• Secure tokens
• IP-based access policy
• Setting up Yandex Cloud CDN location rules