userList.txt $[$it$\text{'}$s saved in the middle server machine$]2)$ Topic $$ ADVANCED OPERATING SYSTEM

$3)$ Total Word Limit Due Date of Assignment$($According to India$)$NA

$4)$ Due Time$($According to India$)$ MON $9$PM

$1.$Objective

The objective of this first programming project is to learn Inter$-$process communication through TCP iterative client, TCP concurrent middle$-$server, and UDP iterative client$-$server interaction using socket interface in Java programming language. After completing the project, you will have a basic$/$intermediate understanding of the steps required to develop a distributed application.

$2.$ Project Specification

In this programming project, you are required to implement a distributed group$-$based shopping system involving TCP and UDP protocols in Java language. The sender process takes the user$-$entered

$"$TCP$-$Group server" IP and port from using the keyboard. Next, it sends login credentials along with current member credit points to the TCP$-$Group server. The TCP$-$group server displays the message and verifies the credentials. If it is correct then the member's credit point is updated and a success message is sent back to the client. The TCP$-$Group server is a concurrent server. Upon successful login$,$ the Group server communicates with a dedicated Silver$/$Gold$/$Platinum server to conduct the shopping process. The entire process diagram and more specific project description are given below:

Detail specifications:

$$The sender process establishes a TCP connection with the middle server. Your sender program needs to take at least two arguments that specify the IP address and port number of the Middle server that it will try to connect.

$$After a successful connection, your sender program will first prompt a welcome message that asks the user to key in a username and password $($keyboard$).$ This credential will then be sent to the middle server. After receiving the username & pwd from your sender$,$ your middle server will send an acknowledgment message back to the sender$.$

$$You have to use $(10000+$ last $4$ digits of your student$-$id number$)$ to avoid requesting the same port by multiple students. The group server gets the middle server port number $+1.$

$$Your middle server process is responsible for verifying the user authentication and the group server details based on points.

$$Upon valid credentials, the middle server will connect the client with a proper group server.

$$Group servers have their own item list with item price and quantity. The client will receive the list from the group server and purchase items based on available credit points.

$$After shopping, credit points remaining will be updated along with item quantities.

$$userList$.$txt $[$it$\text{'}$s saved in the middle server machine$]$

$$Finally$,$ when the shopping is over and the client wants to terminate, the client process will send a CLOSE message to the proper group server. On receipt of a CLOSE message, the group server process should terminate itself gracefully.