Lecture 1. Course Mechanics. Administrative Items. Grading. Programming Assignments. Homework Assignments

Transcription

1 Course Mechanics Lecture 1 Introduction, Course Overview January 12, 2005 Administrative Items Grading Course Organization Homeworks Programming Assignments Exams Administrative Items Course Time: MWF Location: DeBartolo 125 Office Hours: M Location: 354 Fitzpatrick cpoellab@cse.nd.edu TA: Dave Salyers Office Hours: W Location: 214 Cushing dsalyers@cse.nd.edu Grading 40% programming assignments (5) 15% homework assignments (3) 20% midterm 25% final Midterm + final >= 50% correct Programming assignments >= 50% complete/satisfactory Homework Assignments INDIVIDUAL! Deadline: 11.59pm on due date. Meet the deadline! Absolutely NO assignment will be accepted after the deadline has passed. For each assignment: READ CAREFULLY what I expect you to submit. All submissions will be via the drop-box. 3 homework assignments (each 5% of final grade). Programming Assignments INDIVIDUAL! Deadline: 11.59pm on due date. Late submissions: -25% each day. 5 assignments: each 8% of final grade. C, C++, Java only If I explicitly specify C, it MUST be in C. What to submit: source files Makefile (make compiles everything) run scripts and any required results documentation (ASCII, PDF, PS) 1

2 Programming Assignments 40% correctness: does it do what it is supposed to do? did you implement it as required? 20% error handling: I will try to break your code! 20% documentation: comments in code document describing setup, use, solutions 20% evalution: as specified (graphs, tables, ) Documentation! Worth 20% of each assignment! Write in clear English, check spelling. Must explain: setup, platform, file descriptions, how to use it, design of implementations, problems encountered, how solved Setup and run scripts: if it takes me too long or too much effort to run your code you will lose points. Brief comments on code functionality: if it takes me too long to understand your code you will lose points. More About Assignments If program doesn t work fully, mention it in the documentation, explain problem. WHAT NOT TO WRITE: I couldn t figure out how to fork a process, so I did it all in one process Even after spending all day yesterday on that problem I was not able to solve it I did not find any documentation on how to use pthreads More About Assignments Use consistent indentation. Use meaningful names for variables and constants. No compiler warnings allowed. Try to avoid global variables. Typing make will compile everything. Exams Midterm: before break, 20%. Final: May 4, 25%, about 80% from second half of semester. Both are open book. Short-answer questions, long-answer questions, programming questions. More About Grading I will check systematically your assignments for plagiarism. both parties will receive 0% on assignment and will face possible further actions You will receive a file in your dropbox or an regarding your grade for each assignment and exam. If questions about grades, come to my office hour. In addition, I may call you into my office: if I have problems running your code, if I suspect plagiarism, randomly. 2

3 Textbook Douglas Comer and David Stevens, "Internetworking with TCP/IP, Vol. III: Client-Server Programming and Applications, Linux/Posix Sockets Version", Prentice Hall, ISBN: , 1st Edition. Papers and handouts will be provided throughout the semester. Other useful books: W. Richard Stevens, "Advanced Programming in the UNIX Environment", Addison-Wesley Publishing Company, ISBN: C, C++, Java programming books, Linux books, etc. Resources Course structure (particularly syllabus) subject to change! Check frequently for announcements. Mailing list. Drop-box. BE VERY SPECIFIC WITH YOUR QUESTIONS! Don t ask My program crashes all the time, can you have a look at it? Use man-files, Google, textbooks, friends, Any Questions? Lecture 1 - Part 2 Introduction Systems Programming 3 focus areas: Systems: Unix/Linux environment, how to build distributed systems/services, OS support Network: how to use TCP/IP, etc. Internet: distributed programming, FTP/HTTP/Mail/ servers, P2P, Grid, Topics To Be Covered Unix network programming Thread programming Socket programming Client-server programming Servers implementations RPC NFS Java RMI, CORBA Web services, multimedia, CGI, security, kernel programming, P2P, 3

4 What s the Internet? Interconnection of networks. Users ( Europe: 231 million North America: 222 million Asia: 258 million World: 813 million Web applications run on top of the Internet, exploiting its infrastructure (Internet is the infrastructure). Internet Traffic Feb HTTP: 61% NNTP: 12% FTP: 4% Napster: 4% SMTP: 3.5% DNS: 1.1% RealAudio: 1.2% Games: 1% Distributed System Program involving several machines in its execution. Examples: ebay, amazon, travelocity cnn, nfl, mba, nd, Napster, Gnutella, chat air traffic control Simple Example 2 hosts. 2 message types: send_ip_packet and recv_ip_packet. BUT: packet loss, duplication, corruption, reorderings, deadlines, loss of connection, scalability, meaning of data, Solution: protocols. TCP/IP protocol suite Not the OSI reference model (7 layers). Internet Protocol Suite. TCP are IP are fundamental, hence the name. 4 or 5 layers (depending on who you talk to). Layer 5: application (telnet, ftp, http). Layer 4: Transport (TCP, UDP). Layer 3: Internet (IP, ARP). Layer 2+1: Network Access (datalink + physical, Ethernet). Client-Server Model TCP/IP: messages, retransmission, timeout. Client-server: rendezvous problem (who initiates). Client: typically initiates communication (web browser). Server: waits for incoming communication requests from clients (web server). 4

5 Terminology Connectionless servers: UDP. Connection-oriented servers: TCP. Unlike TCP, UDP adds no reliability, flowcontrol, or error-recovery. Stateless vs. stateful: state information about interactions with clients. Example: read a file. When stateless? 5