CS 5523: Operating Systems Homework 4 !!!!! No late HW will be accepted !!!!!! (Check BlackBoard Learn for due date and submission) Objectives  Learn and practice client-server paradigm and peer-to-peer paradigm  Implement a simple distributed system using Java RMI. Description You will design and implement a simplified tracking and chatting system, where a server keeps track of the registered clients and provide necessary information for clients to directly send each other short messages when they come close. You will implement a server program and a client program along with application layer protocol(s) to enable them to communicate. The same client program will be executed several times to simulate different users. The server program will serve client requests and maintain all the below mentioned information about each active client in a linked list. (Note that Java RMI automatically uses multiple threads to process requests originating from different clients.) Each client will connect to the server and register itself by reporting its initial (x,y) location along with other information such as name, age etc. The server will assign a unique ID to each client and send this ID to the client. The client program should be able to get the short messages that might be sent by other clients (peers) and print them on the screen. So the client program should also register the additional information that makes this possible to the server and server should maintain that information too. After the registration step, the server program will wait for clients' requests and accordingly respond to them. A client's main thread can make the following requests (which are entered by the user running the client program): 1. go -50 30 : client wants to go 50m South and 30m East, server updates the location and reports the new location (go 40 -20 means go 40m North and 20m West) 2. get location : client wants to know its current (x,y) location, server reports the current location of this client 3. list 30 : client wants to get the list of users within 30m, server determines such clients/users within 30m of requesting client and send their information (user-id, name, age, additional info) to the client, client keeps that list in a linked list and prints their user-id, name, and age on the screen 4. send user-id msg : client sends msg directly to user-id. Server not involved here. 5. quit : client leaves the system, server takes it out from the list Clearly, there will be some shared resource at the server and/or client so you need to protect them and implement necessary synchronization mechanisms.Run the rmiregistry and server program on hostA as follows: hostA\> rmiregistry [port] & hostA\> java server & Run each clients on different hosts as follows: anyhost\> java client –SH hostA -N name -L x y –A age ------------------------------------------------------------------------------------------------------------------------------- Grading: This is a 200-point homework. First write a 2-3 page report (20 points) to describe your design choices at the high level and particularly describe your remote objects and the services they provide... Then implement your server and client programs and make sure client can register and be able to interact with the server to update its locations, get list of other users etc. (100 points) Finally, enhance your client programs so that clients (peers) can send each other messages through remote objects. (This part will be 80 points) ------------------------------------------------------------------------------------------------------------------------------- Submission You must submit your work using Blackboard Learn and respect the following rules: 1) All assignments must be submitted as either a zip or tar archive file unless it is a single pdf file. 2) Assignments must include all source code. 3) Assignments must include an output.txt file which demonstrates the final test output run by the student. 4) If your assignment does not run/compile, the output.txt file should include an explanation of what was accomplished, what the error message was that prevented the student from finishing the assignment and what the student BELIEVES to be the underlying cause of the error.