Airline Reservation System Dr.Paul Schragger Distributed Systems

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Airline Reservation SystemDr.Paul
SchraggerDistributed Systems

• Presented By
• Archana Annamaneni

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INTRODUCTION

• The software used to drive real-world airline
  reservations is complex. It needs to respond to
  thousands of simultaneous users and interact with
  constantly changing flight data.
• The airline reservation software developed in
  this project, only models a small number of
  transactions
• TechnologyJAVA RMI

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PURPOSE

• The primary purpose of doing this project is to
  learn the concepts of distributed systems and to
  learn JAVA RMI technology.
• Transferring data is basic computational
  operation. Javas message-method paradigm
  transfers data from a calling object to a called
  object within a single Java virtual machine.
• We can cross virtual machine boundaries using
  sockets, to transfer data from one host to
  another .If we consider both paradigms- method
  calls and sockets achieves the same goal the
  transfer of data. 
• If we consider the two methods, its easier to
  invoke a method than to send a message over a
  socket. And RMI achieves to send data to a remote
  host as easily as we invoke a method.

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Architecture
Database
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USE-CASES

• Actor searches for a flight
• Actor makes reservation
• Actor searches for an active reservation

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Activity Diagram

• desired flight exists
• Actor leaves

Actor selects a flight
Actor makes reservation
Actor searches for a flight
Actor looks for active reservation
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Implementation

• The following are the three transactions
  implemented in the project
• Search Flights returns each flight details
  stored in the database
• Book Seat It does a reservation for a specified
  passenger and a flight. The transaction makes
  several simplifying assumptions like the
  passenger and flight must already exist as
  entities the transaction does not create new
  passengers or flights. It informs if the flight
  does not exist, and if it does not reserve a
  seat.
• Show Reservation returns the reservation
  information for a specific passenger identified
  by passenger number. It informs if the passenger
  does not exist

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• Class Diagram

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Actor Searches For A Flight
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Actor makes reservation
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Actor looks for an active reservation
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Issues Covered Related To DS

• Scalability
• Concurrency
• Openness

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• int theReservationNo si.lockSeat(theConnection,f
  light_no ,passenger_no)
• String query "Delete From LockedSeat Where
  ReservationNo "theReservationNo
• int n st.executeUpdate(query)

• int seats flight.getSeats()
• int reservations flight.getReservations()
• if(reservations gtseats)throw new
  FlightBookedException()
• flight.setReservations(reservations1)
• flight.dbWrite(db)
• query "Insert Into LockedSeat""(ReservationN,Fli
  ghtNo ,PassengerNo,TimeStamp) Values
  ('"theReservationNo"','"theFlightNo"','"thePa
  ssengerNo"','" new Timestamp(new date())"')"
• int up st.executeUpdate(query)
• db.commit()

Reservation res new Reservation(theReservationNo
, flight_no ,passenger_no)
int reser res.dbWrite(theConnection) Flight
flight Flight.getInstance(db,flight_no) Int
reservationsflight.getReservations() Flight.serR
eservations(reservations-1) Flight.dbWrite(db) d
b.commit()
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Key TechnologyRMI

• RMI Registry
• A naming service is an application that runs
  on a central server and functions like a phone
  book
• In RMI , the default naming service that
  ships with JDK is called the RMI
• Registry
• Server serverInterface s new serverImpl()
• Naming.rebind(rmi//localhost1099/
  ARServer,s)
• Client serverInterface theServer
  (serverInterface)Naming.lookup(rmi//localhos
  t/ARServer)

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Key Technology Continued

• theServer.searchFlights()
• marshal parameters
• send request
• unmarshal parameters
• invoke
  implementation
• 
  return Flight
• impl
• receive return(or
  exception)
• marshal return(or
  exception)
• skel send reply
• unmarshal reply
• stub return value(throw exception)

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Conclusion

• How Important Design and Analysis is?
• Real time problems while developing a
  distributed application
• Ways to implement Synchronization