As mentioned in an earlier blog post (Four Ways to Purge CDN Content), purging CDN cached content by tag enables you to clear the cache of content that contains one or more of the submitted list of tags as defined by your origin server.
Tags are assigned to cached content via an X-Tag response header, and are stored as metadata with cached objects so that global purges take only seconds, targeting a granular, finite set of cached objects.
To set up a tag header for an asset on your origin, simply add an X-Tag response header to that object.
An X-Tag header can have multiple tags, separated by a comma. Purge by tag assumes comma delimited values.
Highwinds automatically caches all headers that are set by the origin (with some exceptions like transport related headers) without passing them to the end user.
To purge content by tag, simply log in to our StrikeTracker CDN management portal or purge programmatically using our RESTful APIs.
Purge by Tag via StrikeTracker
Purge by Tag Using cURL
In addition to purging content by tag, you may also purge by header, path and URL.
Purge receipts are very important to Highwinds’ customers. Some CDNs let users know their purge requested was submitted. Using StrikeTracker purge capabilities, Highwinds’ users know that their content has been completely purged system wide.
By Sabina Zafar, Director, West Coast Solutions Architect, Highwinds