Outline for February 15, 2001

1. 1. Greetings and felicitations!
   1. Tuesday, Feb 20 3-4:30: Friday Feb 23 1:10-2:30; go to 1101 Hart Hall to view
2. Application: clock synchronization in the face of faults
   1. interactive convergence algorithm
   2. interactive consistency algorithm
3. Example of time protocol: NTP
4. Distributed File Systems
   1. Goals: network transparency, high availability
   2. Architecture: flat (all servers); have specific file servers and clients
   3. Critical services: name server (resolves file names), cache manager (speeds accessses up)
5. Building Blocks
   1. Mounting: binds differing name spaces to a single global view of the name space
6. Mounting
   1. Put the name space at a point in the file tree, as a directory (mount point)
   2. Mount table maps mount points to remote file servers
   3. Maintain mount info at client: each client mounts file systems individually; updates in client (NFS)
   4. Maintain mount info at server: every client sees identical name space; updates at server only (Sprite)
7. Caching
   1. Reduces delays in file accesses
   2. Copy data to local client ; exploits temporal locality
8. Hints
   1. Like caching, but regard data as not reliable
   2. Example: store name resolution data, and work from closest back; invalidate cache entries on failure
9. Encryption
   1. Use Needham-Schroeder (describe generic protocol)
10. Naming

Matt Bishop Office: 3059 Engineering Unit II Phone: +1 (530) 752-8060 Fax: +1 (530) 752-4767 Email: [email protected]

Copyright Matt Bishop, 2001. All federal and state copyrights reserved for all original material presented in this course through any medium, including lecture or print.