1. ITIS 1210 Introduction to Web-Based Information Systems
Chapter 26
How Grid Computing Works

2. Introduction Computers used to be described by their size:
Mainframes
Midi-computers
Mini-computers
Personal computers
Ultra category was the supercomputer

3. Introduction Largest computer today isn’t a single machine
It’s a collection of tens of thousands of normally-sized computers
Their power is in their combination and cooperation
This is grid computing

4. Introduction Theory is simple
Combines computational power of individual computers
Across a network – the Internet or some other network
A main server (or servers) breaks up the computational tasks into subtasks and assigns them to individual computers

5. Introduction
When those computers have idle time, they devote their resources to working on those computational subtasks
Results are reported back to the main server
The main server collates all the results and solves the problem

6. Introduction Many implementations so far Largest is SETI (SETI@home)
Search for Extraterrestrial Intelligence
Overseen by U. California, Berkeley
4,000,000 people in 226 countries downloaded a screen saver
When their computer was idle it analyzed radio signals

7. Introduction Also used for mapping genomes and analyzing proteins
Similar grids could be used by corporations
Idle time on any corporate computer could be used by the corporation
IBM and Sun already use this concept

8. Introduction No standard architecture yet
But moving towards one
Basic use is in solving a large, complex computational problem
That can be subdivided into individual subtasks

9. How Grid Computing Works
Starts by user sending request to main cluster server
Main server determines which resources are available
Subtasks are created and distributed to local cluster servers

10. How Grid Computing Works
Local cluster servers identify computers in their network that are available
Subtasks are sent to those computers on this local network
Each computer processes its data and sends results back to the local cluster server

11. How Grid Computing Works
Local cluster servers collects and collates individual results
Those results sent back to main cluster server
Main cluster server compiles all individual results
Sends answer to problem back to user

12. How Grid Computing Works
Visual Grid
Grid.org