This repository contains minimal, educational examples of different concurrent server design patterns in Python. Each server demonstrates a classic approach used in Unix/Linux systems programming: forking, multiplexing, preforking, and more.

The goal: keep the code small and focused so you can learn the concepts without distractions.

The test client works with all servers:

client.py

Run a server in one terminal:

python server01.py

Run the client in another:

python client.py -i localhost -p 2000 -c 5 -t 10 -b 1024

Extra socket programming tricks and demos are available in the misc/ folder:

• RST Packet Generation
  Demonstrates how to send TCP RST packets using SO_LINGER.

• SIGPIPE Demo
  Shows what happens when writing to a reset socket.

• Self-Pipe Trick
  Classic technique to avoid race conditions with select.

• Sendfile Optimization
  Efficient file transfers using the sendfile(2) system call.

• TCP Concurrent Server, One Child per Client
• TCP Concurrent Server, I/O Multiplexing (select)
• TCP Preforked Server, Children Call accept
• TCP Preforked Server, Descriptor Passing
• TCP Concurrent Server, One Thread per Client
• TCP Concurrent Server, I/O Multiplexing (poll)
• TCP Concurrent Server, I/O Multiplexing (epoll)
• TCP Prethreaded Server
• TCP_CORK socket option examples
• Documentation for every example

• Unix Network Programming, Volume 1: The Sockets Networking API (3rd Edition) by W. Richard Stevens, Bill Fenner, Andrew M. Rudoff
  The classic. Many techniques here are drawn from this book.

• The Linux Programming Interface by Michael Kerrisk
  Another excellent reference.