nz-google-file-system课件.pdf

Seminar Presentation for CSC 456 (Operating Systems) Instructed By: Sandhya Dwarkadas Google File System based on the paper Google File System by Sanjay Ghemawat, Howard Gobioff and Shun-Tak Leung Naushad UzZaman University of Rochester 06 December 2007 Google File System 1 • Search engine • Extended their work to: – Google Video – Gmail (started with 1GB storage, now 6 GB/account) – Google Earth, Maps – Google Products – Google News – And many more.. Google File System 2 Google Operations • More than 15K commodity class PCs • Multiple clusters distributed worldwide • Thousands of queries served per second • One query reads 100s of MB of data • One query consumes 10s of billions of CPU cycles • Google stores dozens of copy of the entire web • Conclusion: Need large, distributed, highly fault tolerant file system, i.e. GFS (Google File System) Google File System 3 Distributed File System • Distributed File System: A file system that joins together the file systems of individual machines in network. Files are stored (distributed) on different machines in a computer network but are accessible from all machines. • Distributed file systems are also called network file systems. • Source: /guide/glossary.html Google File System 4 Examples of Distributed File System • Distributed file systems – Andrew File System (AFS) is scalable and location independent, has a heavy client cache and uses Kerberos for authentication. Implementations include the original from IBM (earlier