Contrary to popular belief, sometimes having long TTL objects in your cache is bad for business. In this instant-update era, Google+, Twitter or Facebook socialites crave the latest memes, while being repulsed by old contents - even if they are mere seconds past the use-by date. Enter purges and bans in Varnish Cache.
For those that are familiar with purges and bans in Varnish, Varnish Administration Console (VAC) now provides a quick way to execute and save bans.
Ban Management in the VAC leverages the bans mechanics in varnishadm and provides a direct access to execute ban in groups; that means the bans are carried out against a group of Varnish Caches. Ban expression is built by fields supported in VCL and the VAC supports the most commonly used fields - req.http.url, req.http.host and obj.http.Content-Type.
The Ban Management also provides a “quick bans” mechanism for a hassle-free way of executing a ban. Furthermore, it can also be used for those that uses various other VCL fields in addition to the fields already mentioned. Bans are saved and can be reloaded at a later stage.