Discuss whetherclients in the

Sprite guarantees that cients never see stale data.When a file is opened for write-sharing by multiple clients,all caching for the file is disabled and all operations are sent directly to the server. This scheme guarantees consistency of data.In AFS,writes to files are performed on local disks,and when the client closes the files,the writes are propagated to the server,which then issues callbacks on the various ***d copies.During the time the file is written but not closed,the other clients could be accessing stale data.Also even after the file is closed,the other clients might access stale data if they had performed the open on the file before the updating client had closed it.It is only at the point of time when the next open is performed on a caching client that the server is contacted and the most recent data propagated from the server to the client.NFS uses a more ad-hoc consistency mechanism.Data is fushed from the clients to servers at periodic intervals and on file close operations.Also a client caching the file data checks for inconsistencies also at periodic intervals.Any updates made and flushed to the server during these intervals are not seen immediately on a client caching the file data.