Transcript Embedded System Project - Arizona State University

Development of a fault-tolerant distributed system environment
based on Windows CE PDA and Visual Studio .Net technologies
(Sponsored by Microsoft Embedded Systems Research)
Dr. Yinong Chen <[email protected]>
Software Research Laboratory
Computer Science & Engineering Department, Arizona State University
Requesting a new Account
Sample Services implemented
Service Requestors




Service
Manager
Database Backend
Web
Services
Provider

Service
Agents
tblUser

Fields:
Key: usrUD

relServices
Service
Scheduler

Name
Pass
FK: usrID
Info
FK: srvcID

Scheduler
tblServices
Soft
Real-Time
Queue
Fields:
Key: srvcID
Windows CE
Priority
Queue
Service Name
Usage
Pocket PC
Dispatcher
(service activator)
Info
.Net
S1 S3 S2 S4
XML, SQL
.Net
Runtime
A Scenario of Execution
1 A client requests to register;
2 The client fills out the required information;
3 The server stores client info into its
database;
4 The client requests a service;
Server
Client
XML Writer
XML Reader
5 The service manager verifies the client info
and sends the request to service scheduler if
approved;
6 The scheduler puts the request into one of
the queues
Server Side
Processing
7 The service scheduler binds the request to a
service agent;
8 The service agent performs the required
service;
XML Reader
XML Writer
9 The service agent sends results back to the
client.
Reference:
Y. Chen, A Service Scheduler in a Trustworthy System, The 37th Annual Simulation Symposium, Arlington VA, April 2004, pp. 89-96.