Description
Overview
The objective of this assignment is to exercise your knowledge about Google Protocol
Buffers and gRPC by building a tiny SNS, similar in concept with posting and receiving
status updates on Facebook or Twitter. In this service, the following must be considered:
1. Each user(client) has his/her own ‘Timeline’. The user is allowed to post to his/her own
timeline. That is, whenever a new user appears, the server needs to create a new
timeline for the new user.
2. A user is allowed to follow any other user after submitting the FOLLOW command. For
example, when a user posts an update to his/her own timeline, followers can see it on
their own timelines.
3. All timeline must be persistent, i.e. their contents must be stored in files in the local file
system. The files must not be encrypted, for now.
4. A user operates in two modes:
○ command mode
○ timeline mode
When the client program starts, it automatically starts in command mode. The
commands the client can send are: FOLLOW, UNFOLLOW, LIST, TIMELINE
5. The LIST command retrieves from the server the list of existing users and the list of
users who follow the current user.
6. The TIMELINE command switches a user from command mode to timeline mode and
allows the user to post some updates to his/her own timeline, which would then appear
on his/her follower’s timelines too.
7. Once a user issues the TIMELINE command, it can not return to the command mode,
and it will stay only in timeline mode.
8. The UNFOLLOW
user’s timeline.
9. The FOLLOW
timeline.
10. After submitting the FOLLOW command, the user sees only new posts. That is, the user
can not see any posts that were posted before the user started to follow.
11. After submitting the TIMELINE command, the user sees the last 20 posts as follows:
“username”, “posting time” and “actual posting”. The posts are expected to appear in the
decreasing order of posting time i.e., the most recent post appears first.
12. All communications will be using Google Protocol Buffers v3 and gRPC. It is expected
that the client doesn’t wait to pass an input or press the enter key to receive and print a
new post in the timeline.
13. The client and server must be started in the following ways:
○ Server: ./tsd -p
Key Points
The running system will consist of the tiny SNS server (tsd) and the tiny SNS client (tsc). As an
environment, you could use the AWS Cloud 9 platform where Google Protocol Buffers v3 and
gRPC will have to be installed, and develop the program in C++. (See the document
“Programming Guide HW2” and “Environment Setup”)
What To Hand In
● Design
Before you start hacking away, write a design document. The result should be a system
level design document, which you hand in along with the source code. Do not get carried
away with it, but make sure it convinces the reader that you know how to attack the
problem. List and describe the components of the system: Client/Server Program, and
their interaction.
● Source Code
Hand in the source code, consisting of a makefile, a file tsd.cc, a file tsc.cc and any
auxiliary files (for example Google protocol buffers and gRPC files). The code should be
easy to read (read: well-commented!). For this assignment, we will not stress test your
code. As long as the code executes correctly for all the sample test cases, you will likely
receive full credit. The instructors reserve the right to deduct points for code that they
consider undecipherable. The code is expected to be submitted using Github. Please
follow the instructions below
● Github
Instructions associated with Github submission:
1. If you haven’t created a Github account, it is advised that you create one. It is
preferred if TAMU Github is not used as it interferes with the repository pull
mechanism for grading.
2. Create a private repository that will contain all machine problem submissions for
CSCE 438
3. Please add the TA and grader as collaborators so that they have access to the
repository for the purpose of grading submissions :
a. cerodav
b. Harshithahk
4. For every machine problem, create a separate subdirectory under the
CSCE 438 repository. Please ensure that the sub directory follows the
naming pattern ‘MP_{machine_problem_number}’. For e.g. for machine
problem 2, this sub directory would be named as MP_2
● How to submit ?
Please refer to the Canvas MP2 assignment page. A google form link will be
posted there and every student will have to fill all the requested information.
Apart from this, make sure that the design documentation is uploaded via
Canvas assignment submission system.
Grading Criteria
● 20% Complete design documentation
● 20% Successful compilation
● 60% Successful completion of 6 test cases. Refer to the attached sample test cases
which cover most scenarios. The ones used for grading would be slightly different.
References
● An Introduction to gRPC and Protocol Buffers for Beginners
● grpc.io
