1. 1 Prototype Design of an Evolutionary Trustworthy Web Server  Hons Project Fall 2003

2. 2 Assumptions Use off-the-shelf client software Use.Net framework.Net framework cannot be modified Not use off-the-shelf web server, e.g. MS IIS (Internet Information Service) We will write a simple server software We will write simple service agents

3. 3 Implementation Overview Clients off-the-shelf Service Provider Agents Service Agents Service Scheduler C# Multithreading in.Net Framework Web Server

4. 4 Service Scheduler Distributor Priority queues S1S3S2S4 requests from Service Provider Q S1 Q S2 Q S3 Q S2 Service Scheduler.Net Runtime Dispatcher (service activator)

5. 5 What Can Be Scheduled Service Scheduling  Which service agent should be activated?  Will be implemented in the prototype Task Scheduling  Which process (all tasks and agents in the system) should be executed?  Should be implemented in the infrastructure (OS)  Will not be implemented in the prototype

6. 6 Implementation Consideration Each task, agent, or object is a C# thread Threads are organized in a hierarchy The main() will activate two threads:  Service Provider, which will activate: service agents  Scheduler, which will activate distributor priority queue agents dispatcher, which will activate the selected service agent

7. 7 Dispatch Policies Select the most critical service first; Dispatch the request with the highest priority; Each service agent will start a quantum timer at the beginning. When timeout, the current process is saved, put back into its queue, and another request is dispatched

8. 8 Task Allocation Vishnu: Write graphic user interface Generate clients and service requests Write simple service provider Explore wireless communication option Foad Write Service Provider Agents. These agents take registration request from clients, opens and manages user accounts generate password take service requests, verifies user id and password handle statement requests Yinhui Write the service scheduler. It takes approved requests from service provider; put different service requests into different queues select a request from the queues and call the service provider to handle the request.

9. 9 2 weekscomplete the preparation of C# multithreading programming and read the sample programs from last semester. 2 weeksEach has the main program done, in which you have created multiple threads, each thread will do one job. Three of you have decided the interface among you. 2 weeksYou have the threads implemented and individually tested. Remaining time (about 2 weeks): test the system together. Time Table from 10/07/2003