tion and manual resolution when needed.The purpose of hoarding is to allow for a future disconnected period. This must be done in order to minimize cache misses during disconnected operation. These misses would result in failure. The way to go about hoarding brings about more problems. The hoarding algorithm should maximize needs based on immediate and future working-sets, future voluntary disconnections, client cache size, and the users conditional utility function. The current algorithm is based on object priorities. The priorities have two components: component s represents how recently the object was used and the hoard priority (m), which represents the objects expected future value to the user. The user can influence these by using the up front program named hoard for assigning hoard priorities, setting the horizon parameter (controls relative weighting of m and s) and setting the decay parameter (controls rate at which s decreases).The purpose of server emulation is to provide the illusion of connectivity to the user and to allow for a smooth transition back into connected mode. To provide the illusion of connectivity the pseudo-server must precisely emulate the actions of the real server.The client will request an object and a few system calls will be made just as they are in connected operation. The kernels VFS will then determine the file to be in the coda directory and the request will be passed off to Venus. Venus then checks the local cache for the file. If it is there it is read from the local disk, if not there is a cache miss. The call then fails and the illusion of connectivity is lost. It can be seen how this phase is heavily dependent on the hoarding phase. The second part of the server emulation phase is preparing for reconnection. The pseudo-server logs all actions that change or destroy a file onto the CML (Client Modification Log). During reintegration all updates must be passed on to the server so t...
