CS 6378: Advanced Operating Systems

Project 1
Instructor: Prof. Neeraj Mittal
Author: Malay Virendra Bhavsar (MXB230055)

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Project Overview

This individual project implements a distributed system using the Chandy-Lamport snapshot-taking protocol and the MAP (Message Active Passive) protocol. Developed in Java (Version 22.0.2), the project emphasizes socket programming and distributed communication, running exclusively on the dcXX.utdallas.edu machines.

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Project Components

The project comprises several essential components:

• Node: Sets up Client, Server, and ChandyLamport instances; manages the configuration file.

• Server: Oversees incoming communications and directs them appropriately.

• Client: Manages outgoing communications, including application and control messages.

• ChandyLamport: Implements the snapshot protocol and ensures the consistency of snapshots.

• Message: Establishes a structured format for inter-process message exchange.

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Project Segments

The project is divided into four main segments:

1. Part 1: Implement a distributed system with n nodes, each able to send messages according to the MAP protocol. Nodes transition between active and passive states based on message counts and delays.

2. Part 2: Integrate Chandy and Lamport’s protocol to record a consistent global snapshot, initiated by node 0, to detect the termination of the MAP protocol.

3. Part 3: Implement Fidge/Mattern’s vector clock protocol to verify the consistency of snapshots through vector timestamps.

4. Part 4: Create a protocol for halting all nodes after node 0 detects MAP protocol termination.

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Configuration Format

The project utilizes a plain-text configuration file formatted as follows:

• The first line contains six tokens:
  • Number of nodes
  • minPerActive
  • maxPerActive
  • minSendDelay
  • snapshotDelay
  • maxNumber.
• The next n lines specify node details:
  • nodeId
  • hostname
  • port
• The subsequent n lines list neighboring nodes.

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Output Format

For a configuration file named <config_name>.txt with n nodes, the program will generate n output files named <config_name>-<node_id>.out. Each file contains vector timestamps for each snapshot recorded by the respective process.

Example Output:

0 4 3 6 0 2 3
3 7 6 7 2 4 4
6 9 11 10 5 7 5
8 12 14 23 8 10 7

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Getting Started

Prerequisites

• Ensure you have Java Development Kit (JDK) 22.0.2 installed.
• This project must be executed on the machines dcXX.utdallas.edu (where XX ∈ {01, 02, ..., 45}).

Setup Instructions

1. Create a project directory:

   mkdir aos-project1
   cd aos-project1

2. Place all project files (including the configuration file) in this directory.

3. Compile the project:

javac *.java

4. Clean up before and after running the program:

chmod +x cleanup.sh
./cleanup.sh

5. Run the program:

chmod +x launcher.sh
./launcher.sh

6. Perform cleanup after use:

./cleanup.sh

Connecting to the Server

To connect to the server at dcXX.utdallas.edu, use the following command (omit the password):

ssh <your-username>@dcXX.utdallas.edu

Ensure that you replace with your actual username. After connecting, you can navigate to your project directory to compile and run your code.

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Acknowledgments

The ./launcher.sh and ./cleanup.sh scripts are provided by the professor. All credits go to the respective owners for these contributions.

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Conclusion

This project delves into the intricacies of distributed systems, showcasing effective communication and state consistency through the Chandy-Lamport protocol. We encourage you to explore these concepts deeply and enhance your understanding.

If you have any questions or require further assistance, please don't hesitate to reach out!

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