CIS 4400 Project Specification

Due: Presentations to be scheduled

 

 

 

Develop a program package to simulate a toy distributed system by using the TCP(UDP)/IP. Your program must be able to run on several computers. On each machine, there are a set of concurrent processes and a communication server process. The system architecture is shown in Figure 1, where Processor 1, 2 and 3 are computers of your system installed with a communication server. Each processor hosts many concurrent processes such as ti's, si's and qi's(Note, a process can have an arbitrary symbolic name).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 1: System Architecture

 

The concurrent processes use high level system primitives:  register, terminate, send

and  receive to communicate with the system and with each other.

 

 

• void register(process_name);
• void terminate(process_name);
• void send(process_name, msg);
• int receive(process_name, msg);
• int block_receive(process_name, msg);

 

 

where  process_name and  msg are character strings. Communication primitives adopt asynchronous protocol. For primitive receive, a special process_name “ANY” can be used to receive a message from any process. The return value of a receive-like primitive is either 1 or 0, the former indicates a successful execution and the later means that there is no available message or the sender does not exist.

 

For example, a process Romeo might have the following code skeleton:

 

  int main(){

              register(“Romeo”);

              send(“Juliet”, “Date tonight, Be there or be square”);

              block_receive(“Juliet”, msg_buffer); 

              processing(msg_buffer);

              terminate(“Remeo”);

}         

 

System primitives talk to its local communication server directly. The message format between a concurrent process and the communication server is:

 

 

where REQUEST can be one of  Registration, Termination, Send, Receive, Block_receive to indicate the task to be performed.

 

A communication server is a midware (a perpetual process) to direct interprocess communications. The major functions are as following:

 

• manipulate a local name cache.
• talk to Name server such as registering a new process, requesting an ip-address of a process which could not be located locally, or de-registering a terminated process.
• manipulate a massage queue for each local process.
• carry out asynchronous (local or global) interprocess communication.
• detect system failures (timeout).

 

Based on your system API, you must conduct at least three tests, such as:

 

Test 1: You should create several concurrent processes running on at least three machines to simulate an election algorithm.

 

The major function of each concurrent process should be:

 

• send a timestamped message to every other concurrent process.
• receive messages from every other process.
• calculate timestamps.
• the process who holds the earliest time announces (broadcasts) a message that it is the net master.

 

 

You should show two sample runs: 3 concurrent processes on each machine and 10 concurrent processes on each machine.

 

 

 Test 2: The second experiment consists of 12 processes, which are connected into a (logic) ring network (at least three machines each holding 4 processes as the ring nodes). A token circulates alone the ring. Each process randomly generates a message and its destination. A process can send the message only when the token is received and then attach the message to the token.

 

 Test 3: You should specify another test case by your imagination.