The Web As A
Global Computing Platform
[Slides from a presentation at the 7th International Conference on
High Performance Computing and Networking Europe. Amsterdam,
the Netherlands, April 1999. Associated paper published in Springer
Lecture Notes in Computer Science, pp. 281-290]
Qusay H. Mahmoud
Etisalat College of Engineering
Emirates Telecommunications Corp.
e-mail: dejavu@acm.org
Outline
Web-based Global Computing
Why Global Computing
Computing using CGI
A Web-based Distributed System
Security Issues
Related Work
Conclusion
Web-based Computing
The Web current computing models include:
Server-side Computing (CGI)
Client-side Computing (Applets)
These are limited computing models
Were initially designed for processing fill-out
forms
Why Global Computing?
Think of the Web as Programmable
That is, use the Web as global computers
Computing-intensive applications need:
More computing power
Better performance
A Global compute server built out of subcomponents (idle nodes on the Internet)
Use as many idle machines on the Internet as
possible
Computing using CGI
Inconvenient: more than one program
Limited I/O: getting input from user
Lack of control
A Web-based System
Compute server with
Dynamic Class Loader
Security Manager
Client (applet, CGI script, stand-alone)
Logging facilities
Searching for compute resources
Broker
Dynamic Class Loader
Modularity: software components are fetched
dynamically, if they are needed
The client sends a URL of the program to be
run by the compute server
The compute server loads the program
dynamically
Client receives results
Security Issues
Loading arbitrary classes over the network is
not secure
The compute server’s file system is at risk
Client’s code may perform some malicious
actions (e.g. deleting files)
Clients may overload compute server
Compute server may crash
Solution
Compute server runs in a restricted
environment (sandbox)
Clients do not have access to compute
server’s file system
A security policy is devised and a custom
security manager is implemented
Searching for Compute Servers
Search engines are used to locate URLs of
homepages
A broker is used to dynamically match clients’
requests
Related Work
ParaWeb: executes parallel program on a
variety of heterogeneous hosts
World-Wide Virtual Machine: a collection of
CGI to extend Web servers functionality
Legion: workstations connected by LANs. It is
not web-based
Globus: enable applications to integrate
geographically-distributed computational and
information resources
Conclusion
Java is a step-forward towards programmable
Web
No language has the Web as its run-time
system
So, we need:
New models of programming and computation for
global computers