If the CacheQube for some reason fails, will users notice the failure?
The CacheQube is a reasonably reliable and stable device; for example, the CacheQube (operating in transparent mode) we use at Cobalt has never failed. Nonetheless, the CacheQube does have a disk and a power supply, and these parts can fail. Users may notice failures, although the details will differ depending on how the CacheQube has been configured. If the CacheQube has been configured to operate in transparent mode, then user traffic (including HTTP traffic) will not be routed to the outside world. If the CacheQube has been configured to operate in traditional HTTP proxy mode, then browsers will discover that the cache is down and will subsequently access the Internet directly. In a Cache Cluster, if a Cluster Slave fails, the Cluster Master will detect the failure and will subsequently stop directing HTTP requests to the failed Slave (it will resume directing HTTP requests to the slave when the slave comes back on line). Finally, if an L4 switch is employed, the switch will detect
