SiteSpect caches content for a predefined length of time using its Cloud service. This means that SiteSpect does not have to fetch resources from your origin web servers every time there’s a request. This shortens network latency and offloads work from your web servers. Settings for content caching are located on the Domains page. See Enable Content Caching on that page for more information.
SiteSpect uses the Apache server for caching. General caching follows the standard Apache rules.
Keep the following in mind:
- Cache settings are determined on a per engine basis; when you initially enable caching, and caching is not consistent across all engines, users will not always received cache content. As the collective caches are populated, cache hit rate will increase.
- For SiteSpect servers to cache objects, be sure that you’re web servers do not prevent caching. Any and all of the following Cache-Control header values prevent caching: no-cache, no-store, max-age=0.
- If max-age is not specified by the cache-control header set by the web servers, SiteSpect caches based on its default max-age setting, which is 60 mins (3,600 seconds). You can customize this value.
- If the URL included a query string (e.g. from a HTML form GET method) it will not be cached unless the response specifies an explicit expiration by including an "Expires:" header or the max-age or s-maxage directive of the "Cache-Control:" header.
- The cache_status_env field in SiteSpect’s Logfile lets you see the caching performed for a particular request. This feature may be found in the Logfiles part of the Control Panel user interface. The cache_status_env field contains any of the following values:
- cache-hit: The response was served from cache.
- cache-revalidate: The response was stale and was successfully revalidated, then served from cache.
- cache-miss: The response was served from the upstream server.
- cache-invalidate: The cached entity was invalidated by a request method other than GET or HEAD.
- You can investigate cache status live by sending an SS-Cache-Debug request header with a value of “1”. The header response values are:
- HIT: The response was served from cache.
- REVALIDATE: The response was stale and was successfully revalidated, then served from cache.
- MISS: The response was served from the upstream server.
- INVALIDATE: The cached entity was invalidated by a request method other than GET or HEAD.