A user's request for content will generate a response from a server. This response consists of response headers. and a response body. The response headers generated for content requested through our CDN describe the response provided by an edge server. By default, our edge servers will include:
This topic describes the following:
Common response headers are listed below.
| Response Header | Description | ||||||||
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| Accept-Ranges |
Indicates whether a server can accept range requests. Default value: bytes Note: The default value indicates that our servers can accept byte-range requests. |
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| Cache-Control: max-age |
Indicates the maximum length of time that a request is considered fresh. An edge server can serve fresh content directly from cache without having to perform a revalidation with the origin server. Default value: 604800 Note: The default value indicates that the max-age for the requested content is 7 daysMax-age is defined in seconds. 604800 seconds = 7 days. |
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| Content-Type |
Indicates the content type for the response body. Sample content types are provided below.
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| Date | Indicates the date and time (GMT) on which the edge server returned a response. | ||||||||
| Etag | Indicates the entity tag (ETag) for the requested content. This ETag allows our edge servers to revalidate stale content. In other words, our edge servers will use ETag when checking with the origin server to see if there is a newer version of the requested content. | ||||||||
| Expires | Indicates the date and time (GMT) at which the response will be considered stale. By default, our edge servers must revalidate requests for stale content. | ||||||||
| Last-Modified | Indicates the date and time (GMT) at which the requested content was last updated. | ||||||||
| Server |
Provides information about the server that fulfilled the request. Syntax (Customer Origin Server) If a cached version of the requested content is not found, then the customer origin server will provide a response.
Syntax (New Content & CDN Storage) The following syntax applies for requests to CDN storage that have not been previously cached: EOS (POP/IDIndicates a four digit alphanumeric system ID. This field is used solely for internal purposes.)
The terms used in the above syntax are defined below:
Syntax (Cached Content) The following syntax applies for requests for cached content: Platform (POP/IDIndicates a four digit alphanumeric system ID. This field is used solely for internal purposes.)
The terms used in the above syntax are defined below:
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| Vary |
Identifies the variant that defines whether cached content can be served for future requests. Key information:
Note: The Accept-Encoding request header identifies the type of compression requested by the client. An edge server may deliver the requested content immediately if the cached asset matches the requested compression method. |
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| X-Cache |
Indicates that a cached version of the requested content was served directly to the requester by an edge server. This response header will be set to the following value:
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| Content-Encoding |
Indicates that a compressed version of the requested content was served to the requester. This response header will indicate the asset's compression type (e.g., gzip, deflate, bzip2, etc.). |
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| Content-Length | Indicates the size of the response body in octets. |
Response headers can be viewed using a variety of tools, such as:
Chrome offers built-in developer tools through which you may view response headers.
To view response headers in Chrome
Tip: If you would like to submit this information to support personnel, right-click on the left-hand pane and then select the Save as HAR with content option. Attach the HAR file to your message.
Firebug is a free browser add-on for Mozilla Firefox.
To view response headers in FireFox
Fiddler is a free web debugging tool. Although it has a variety of uses, it can be used to submit an HTTP request and view the corresponding response from the server. This tool provides a history of the requests submitted during the current session. This history, along with the verbose nature of this tool, makes it a useful troubleshooting tool through which you can diagnose the root cause of your issue.
Wget is a command-line tool that allows you to request content over FTP, HTTP, and HTTPS.
The following sample request will return header data for content delivered over the HTTP Large platform.
cURL is a command-line tool that allows you to request content over FTP, HTTP, and HTTPS.
The following sample request will return header data for content delivered over the HTTP Large platform.