Pull Zone Settings
Here is a list and description of the CDN features that are Pull Zone specific:
Origin Shield
Predefined shield servers, instead of our edge servers, will pull the content from your origin server if enabled. This will reduce the traffic on your origin server but adds an additional request from the edge server to the shield server if the content has not yet been cached. Additional HTTP response header field: X-Shield: active
Max Expire
This value specifies the maximum time for which cacheable HTTP documents will be retained without checking the origin server. Applies only if NOT defined by the origin either by X-Accel-Expires, Cache-Control, or Expires.
Ignore Cache Control
Disables processing of Cache-Control response header fields from the origin server (ignores X-Accel-Expires, Cache-Control, and Expires). Max Expires has precedence if enabled.
Ignore Query String
The feature ignore query string tells the cache to reply with a cached reply even if the query string differs. From a caching point of view the request is treated as if having no query string when this feature is enabled.
Forward Host Header
Commonly used for full site acceleration, this option forwards the Host header Host: www.example.com to the origin server as received from the client instead of the host from the origin URL.
Cache Key Scheme
Scheme based caching as requested by the client, http or https. The Cache Key Scheme and Origin Shield feature are not supported to be both enabled. It is not recommended to enable this feature as it will lower the cache hit ratio.
Cache Key Host
Dynamic caching based on the host header Host: cdn.example.com that matches the Zone Alias. It is required to enable this option if you want to host multiple sites in one Zone. It is not recommended to enable this feature as it will lower the cache hit ratio.
Cache Key Cookie
Cookie variable based caching as received in the client request header. It is not recommended to enable this feature as it will lower the cache hit ratio.
Cache Key Device
Device-based caching, such as desktop, mobile and tablet. It is not recommended to enable this feature as it will lower the cache hit ratio.
Cache Key WebP
Cache WebP images based on the Accept: image/webp header. It requires to enable the feature Image Processing or the origin server to deliver WebP images.
Cache Key Country
Country code based caching derived from the client IP address. Adds the X-Country-Code header to the origin request with the two-letter country code (ISO 3166-1 alpha-2). It is not recommended to enable this feature as it will lower the cache hit ratio.
Cache Brotli
Cache Brotli compressed assets from the origin server (Content-Encoding: br). Only enable this feature if your origin supports Brotli compression.
Cache Cookies
By default, files with cookies are not cacheable. However, enabling this option will ignore the presence of cookies and therefore force the edge servers to cache these files.
Strip Cookies
This feature strips the cookies received from the origin server. The client will not receive the Set-Cookie response header. It is highly recommended to enable this directive if you enable Cache Cookies, otherwise it may create a security risk.
X-Pull Key
Specify a X-Pull request header key to have the possibility to restrict access to your origin server (X-Pull: [key]). Default if empty: X-Pull: KeyCDN
Canonical Header
Add a canonical header in order to improve SEO. Reference is your Origin URL (e.g Link: <http://foo.co/a/b.pdf>; rel="canonical").
Robots.txt
Block crawlers from indexing the content in your Zone.
Optimize for HLS
Sets the Zone settings for HTTP Live Streaming (HLS). The index file .m3u8 will not be cached and it overwrites the directives as follows:
- Expire: -1 (Cache-Control:
no-cache) - Max Expire: 5 (relevant for the
.tsfiles) - Ignore Cache Control: enabled
Generic Error Pages
Disable this option to forward an error page as received from the origin to the client. This applies to 4xx and 5xx errors.