bbserver

Bulletin Board Messages and Distributed Agreement

bbserver is a multi-threaded bulletin board server implemented in C. It allows clients to write and read messages while ensuring data consistency across multiple bulletin board instances.

Purpose

The main objectives of this project are:

• Implement a multi-threaded bulletin board server
• Allow clients to write and read messages
• Synchronize data across multiple server instances
• Provide a practical example of distributed systems and concurrent programming

Features

• Multi-threaded architecture with thread pool
• Client-server communication via sockets
• Readers-Writers lock for concurrent access to the bulletin board
• Two-phase commit protocol for distributed data synchronization
• Configurable server settings
• Daemon mode support
• Debug logging

Dependencies

This project relies on standard C libraries:

• stdio.h
• stdlib.h
• unistd.h
• pthread.h
• signal.h
• string.h
• fcntl.h
• sys/types.h
• sys/socket.h
• netinet/in.h
• sys/stat.h
• sys/resource.h
• stdarg.h
• time.h
• semaphore.h
• arpa/inet.h
• stdbool.h

Installation

1. Clone the repository:

git clone https://github.com/yourusername/bbserver.git

2. Navigate to the project directory:

cd bbserver

3. Compile the server:

make

Usage

1. Start the server:

./bbserv

Or

./bbserv server.conf

Or with a custom configuration file:

./bbserv <condig_file>.conf

2. Connect to the server using telnet:

telnet localhost 9000

Or:

telnet <ip> <port_number>

3. Send commands:

USER Alice
WRITE Hello World!
READ 1
QUIT

4. To stop all instances of the server:

killall bbserv

Configuration

The server can be configured using a configuration file (e.g., server.conf) with the following parameters:

• BBFILE: Path to the bulletin board file
• BBPORT: Port number for client connections
• SYNCPORT: Port number for peer synchronization
• THMAX: Maximum number of threads in the thread pool
• DAEMON: Flag to run as a daemon process
• DEBUG: Enable debug logging
• DELAY: Introduce artificial delay for testing
• PEER: IP and port of peer servers (can be multiple)

Example Configuration file:

BBFILE=bbfile.txt
BBPORT=4100
SYNCPORT=6100
THMAX=10
DAEMON=1
DEBUG=1
DELAY=0
PEER=localhost:3100

Key Learning Points

• Implementation of a multi-threaded server with a thread pool
• Synchronization techniques: readers-writers lock and semaphores
• Network programming with sockets in C
• Implementation of a two-phase commit protocol for distributed systems
• Daemon process creation and management
• Configuration management and logging in C programs
• Signal handling for graceful shutdown and reconfiguration

Conclusion

This project provides practical experience in developing a complex, multi-threaded server application with distributed synchronization. It covers various aspects of systems programming, including network communication, concurrency control, file I/O, and process management in a POSIX environment.