Subscriber-Publisher_app

Short description of application

This project is a small publisher-subscriber application, in which the communication is done via TCP and UDP.

Subscriber (TCP client)

This subscriber client can subscribe to different messaging topics and recieve notifications with the messages that are published.

The TCP clients support duplex communication with the server.

Publisher (UDP client)

The udp clients send messages (UDP datagrams) to the server, under different topics.

Server

• The server acts as a broker between the subscribers and the publisher. It manages the TCP and UDP connections, recieves messages from the publishers and delivers them to the subscribers.

• The server supports two types of communication:

  • simplex - recieve datagrams from UDP clients
  • duplex - send / recieve data to / from TCP clients

• The server supports multiple clients, by using multiplex socket communication.

• The server implements a store&forward feature: while the clients are disconnected, the server can store messages and deliver them to the clients when they reconnect.

Notes

• Running the code

  1. ./subscriber {id_user} {ip_server} {port_server}
  2. ./server {port_server}
  3. python3 udp_client.py {ip_server} {port_server}

• Subscriber commands

  1. subscribe {topic} {SF} (SF = store&forward - 0/1 value that enables the feature to store messages while the clients are disconected)
  2. unsubscribe {topic}
  3. exit