WebOS: Software Support for Scalable Internet Services

WebOS has Moved! The new WebOS homepage is here.

The goal of our work is to provide a common set of OS services to wide area applications, including mechanisms for resource discovery, a global namespace, remote process execution, resource management, authentication, and security. On a single machine, application developers can rely on the local operating system to provide these abstractions. In the wide area, however, application developers are forced to build these abstractions themselves or to do without. This ad-hoc approach wastes programmer effort and system resources. To address these problems, WebOS provides basic operating systems services needed to build applications that are geographically distributed, highly available, incrementally scalable, and dynamically reconfiguring. Our initial implementation is split into the following pieces:

  • WebFS: A global file system layer allowing unmodified applications to read and write to the URL name space. Cache consistency is available to applications requiring it through the AFS protocol.
  • Smart Clients: A mechanism for logically moving service functionality such as load balancing, resource discovery, and fault transparency from the server onto client or proxy machines.
  • Secure Remote Execution: We believe applications will be running on remote nodes on behalf of arbitrary users. Assurances must be provided ensuring that applications are not able to violate the integrity of the remote server and that the servers cannot take advantage of any user access rights provided to the programs.
  • Security and Authentication: Applications accessing remote files must authenticate their identities before access to protected files can be granted.
  • Transactions: Applications must have well-defined failure modes. For example, an aborted remote agent should not leave a user's local file system in an inconsistent state.

An ALPHA version of WebFS is available as a Solaris binary distribution. Release notes are included with the distribution.

Potential projects associated with WebOS.

Internal release of a read only webfs file system to the NOW cluster.


  • "Operating System Services For Wide Area Applications," Amin Vahdat. November 1998.
    PhD Dissertation, Department of Computer Science, University of California, Berkeley--PDF.
  • "WebOS: Operating System Services For Wide Area Applications," Amin Vahdat, Thomas Anderson, Michael Dahlin, David Culler, Eshwar Belani, Paul Eastham, and Chad Yoshikawa. July 1998.
    The Seventh IEEE Symposium on High Performance Distributed Computing--Postscript.
  • "Transparent Result Caching," Amin Vahdat and Thomas Anderson. June 1998.
    Proceedings of the 1998 USENIX Technical Conference --Postscript.
  • "The CRISIS Wide Area Security Architecture," Eshwar Belani, Amin Vahdat, Thomas Anderson, and Michael Dahlin. January 1998.
    Proceedings of the 1998 USENIX Security Symposium -- Postscript.
  • "Using Smart Clients to Build Scalable Services," Chad Yoshikawa, Brent Chun, Paul Eastham, Amin Vahdat, Thomas Anderson, and David Culler.January 1997. Proceedings of USENIX '97 -- Postscript.
  • "WebFS: A Global Cache Coherent Filesystem," Amin Vahdat,Paul Eastham, and Thomas Anderson. December 1996. Technical Draft -- HTML.


The following people are working on the WebOS project:
Amin Vahdat
Last modified: Fri Dec 31 15:34:38 EST 1999