1. Something new
Fresh objects are ready to replace the original content. Freshness is determined by metadata that defines an object's expiration date or maximum age. Freshness can also be determined using an aging factor based on the last modified date of the object.
2. Stale objects
Stale objects are cache objects that are no longer available. Objects that exceed expiration dates or age limits must be recached from the source server before they can be served by a proxy. When stale objects are encountered, the agent also caches updated objects from the source system and sends them to the user.
3. Nonexistent objects
Objects that exist on the server but not on the agent follow the same process as stale objects. If the object exists on the proxy but not on the server, the proxy does not provide a cache copy.
If you want to try to use a proxy server, you can enter Roxlabs proxy server official website to learn more, provide high hiding stable residential proxy services, support HTTP/HTTPS/SOCKS5 proxy protocol, ten million IP resources, ensure the security of data transmission, now there are free tests!