P2P Gossips Protocol

• Subject - Computer Networks
• Semester - Spring 2024

Code Description

• Config file:

  • IP and Port of seed nodes are hard-coded

• Seed:

  • Initializes functions to create and bind sockets create_bind(), write logs write(), and handle incoming connections from peers begin().
  • Implements a thread function peer_conn() to handle peer connections, processing various types of messages received.
  • Upon receiving a connection request from a peer, it responds by sending its peer list.
  • Monitors for "dead" messages from peers and removes them from the peer list accordingly.
  • Listens for incoming connections from peers and spawns separate threads to handle each connection.
  • Provides functionality to listen for and accept incoming connections begin(), manage peer lists peer_conn(), and handle dead peers peer_conn().
  • Utilizes threading threading.Thread to handle multiple peer connections concurrently.
  • Reads the port number for the seed node from user input and initializes necessary variables PORT.

• Reporting the node as Dead:

  • When 3 consecutive liveness requests do not receive a reply, the peer sends a message of the following format to all the seeds it is connected to: Dead Node:DeadNode.IP:self.timestamp:self.IP

• Peer:

  • MessagesLst (ML) being printed in peerlog.
  • Connects to least_integer(n/2)+1 seed nodes.
  • Initializes a Peer class Peer to manage peer addresses.
  • Defines functions to create and bind sockets create_bind(), write logs write(), and handle incoming connections begin().
  • Initiates a listening loop begin() to accept incoming connections from peers.
  • Implements a handler handlePeer() for each peer connection, processing various types of messages received.
  • Provides functionality to connect to other peers peerConnect(), manage peer lists, and handle dead peers peerDead().
  • Implements gossiping among peers handleGossip() by exchanging messages and ensuring message uniqueness.
  • Manages liveness testing work() to monitor peer availability and take action upon failures.
  • Utilizes a worker function work() to manage different tasks such as socket creation, liveness checking, and gossiping concurrently.
  • Utilizes threading threading.Thread and a queue Queue to manage concurrent execution of tasks.
  • Reads seed addresses from a configuration file and connects to a subset of them seedConnect().

• Gossip message:

  • Peer generates msg of the format: self.timestamp:self.IP:self.Msg#

• Liveliness message:

  • If 3 consecutive liveness messages are not replied to, the node will notify the seed nodes that it is connected to, that this particular IP Address is not responding

• Request Message Format:

  • Liveness Request:self.timestamp:self.IP

• Reply Message Format:

  • Liveness Reply:sender.timestamp:sender.IP:self.IP

• Log file:

  • SeedLog file store the connection requests from new peers as well as the output from dead node.
  • Each peer has its own log file where it writes the list of peers it got from seed nodes. Gossip messages are also logged with timestamp.

Execution Steps:

• Clone this repository
• Edit config.txt to add localhost IP address and any port number. Sample has been provided
• Run python seed.py and enter the port number used in config file. Repeat the same for all ports
• Run python peer.py and enter any port number.
• If another instance of peer is started, gossips would start.
• All of this is logged in the output file.