How Caching Works

The following steps describe how caching works in the LoadMaster:

1. The LoadMaster checks if the content is already cached.
2. The LoadMaster checks if the status code in the response is valid. The status code must be 200, 203, 300, 301, or 410 for content to be cached.
3. The LoadMaster checks the Cache-Control header field for the following directives. If the Cache-Control header field has the following data, the LoadMaster will not send the response from the cache:

• no-cache
• no-store
• must-revalidate
• proxy-revalidate
• max-age
• Pragma: no-cache
  Note: For further details on the Pragma: no-cache header, refer to the following page: Pragma.
  Note: The Pragma: no-cache header is for backwards-compatibility with the HTTP/1.0 caches that do not have a Cache-Control HTTP/1.1 header.

1. The max-age expiry time is one hour. The LoadMaster checks the response date and last modified time. If there is no last modified time, the date field is used. If the last modified time is less than 60 seconds from the creation date of the file, it will not cache because it has been modified too recently. If the expiry date has passed, the file is not cached.
2. The LoadMaster checks the size of the file to ensure there is enough space to cache.
3. The file is pulled into memory. If there is chunked encoding, it will be de-chunked.
4. If the file should be compressed, it starts compressing.