This document provides an overview of the design of an online airline reservation system, including: - The main database entities: flights, customers, reservations, purchases, credit cards - Activity and class diagrams showing the system design and interfaces - Class interfaces for authentication, flights, searching, reservations, and credit cards - Methods for registering users, searching flights, making and cancelling reservations, and purchasing tickets - Fault tolerance issues and solutions like two-phase commit protocol, monitoring for failures, and data replication.

1. Online Airline Reservation System
--Detailed design
Pingping Ma
Oct 19, 2006

2. Overview
Database
design
Activity diagram
Class interface
Fault tolerant issues

3. Database design
 There
are mainly 5 entities involved:
 Flight
info.
 Customer info
 Reservation
 Purchase
 Creditcard info.
 Please
slides
see the entity diagram in the next

4. Database design diagram

5. Activity Diagram

6. Major class interface
 Authenticate
 Search
 CreditCard
 FlightInfo
 ReservationInfo

7. Authenticate Interface
 Variable
username, password, email
 Boolean Authenticate (String username, String
password);


This method checks if the user name and password input is a
valid input.
If true, it will return true; otherwise, return false.
 Boolean
Register (String username, String
password, String email)


This method is used to register a new user.
If the register is successful, return true; otherwise, return false.
 Boolean IsAlive (String username)
 This method checks to see if the user is still active when it
doesn’t reponse in a certain amount of time.

8. Flight Interface
A
class about the flight information with
the following variables
 FlightId
 From_City
 To_City
 Dept_Time
 Arr_Time
 Num_Of_Seats
 Price

9. Search Interface
 This
class has only one method Search. Maybe
can be combined with the Flight class.
 Flight Search_oneway (String from_city, String
to_city, Date dept_time, Date arr_time, int
num_of_Seat)
 Flight Search_round (String from_city, String
to_city, Date dept_time, Date return_time, int
num_of_Seat)
 Given the search criteria, searches the database
looking for flights that match the criteria.

10. Creditcard Interface


A class about the credit card information
Variables






User_id
Card_number
Type
Year
Month
Methods





Boolean IsValid()
String GetNumber()
String GetType()
Number GetYear()
Number GetMonth()

11. Reservation Info
A
class about the reservation information.
 Variables
 Reservation_id
 User_id
 Flight
 Credit_card
 Reservation_date
 Num_of_seats
 Passenger_name:
an String array

12. ReserveAndPurchase Method
 Methods
 Boolean
Reserve(String Reservation_id,
String User_id, Flight flightobj, Creditcard cc,
Date Reservation_date, Integer
Num_of_seats, String [] Passenger_name)
 Boolean CancelReservation ()
 Reservation ReadReservation()
 Boolean Purchase()
 If the action is successful, return True;
otherwise, return False.

13. Fault Tolerant issues
A
failure in any transaction step causes
the whole transaction to be lost.
 Possible
Solution: two phase commit procotol
can be used. Or make full use of the
COMMIT, ROLLBACK command in the
database.
 How
to identify a client or server failure?
 Implement
an IsAlive function which ping the
client or server to make sure that it is still
active.

14. Fault tolerant issues
 Synchronization
 Use
monitor method in the Reserve method to
make sure there is no client reserving the
same ticket at the same time
 Data
replication
 Use
data replication techniques to improve
the reliability of the system.
 Use primary copy method to enhance the
consistency of the data.