6.824 Final Project

For our final project for MIT's 6.824 (Distributed Systems), our team implemented a Bittorrent client and tracker in Go.

Team Members

• Nicole Glabinski (nicolekg)
• Everardo Rosales (erosales)
• Kimberli Zhong (kimberli)

Requirements

Requires Go 1.8 or greater, for shutdown of HTTP servers.

You'll also need to install http://github.com/zeebo/bencode/. In the src folder, run go get github.com/zeebo/bencode.

Usage

To run either the tracker or client, go in to src/main and run go run main.go. Run the tracker with flag -tracker and run the client with flag -client. Specify the .torrent file you want to use with -torrent=<NAME>. Other flags include -debug, -port, and -persister, which allows you to save progress to a specific file or restart a stopped download.

You can also generate .torrent files using the main utility. Run a command like go run main.go -generate -torrent=out.torrent -file=<filename> -url=<tracker url>.

Development

• src/client - code for the client
• src/tracker - code for the tracker
• src/fs -
• src/btnet -
• src/github.com -
• src/util - utils for development (e.g. debug printing)
• src/main - the main command-line utility

Testing

Automated Testing

Run tests with go test in the following directories:

• src/btnet - network
• src/client - client
• src/fs - torrent file utilities
• src/main - integration tests
• src/tracker - tracker
• src/util - general utilities

The file main/torrent/test.torrent is used in our unit tests and was downloaded from https://downloads.raspberrypi.org/raspbian_lite_latest.torrent in May 2017. Other test torrents used are in main/torrent.

Manual Testing

Run manual tests with the following commands:

• go run main.go -tracker -port=8000 -torrent=torrent/puppy.torrent -debug=Info
• go run main.go -client -port=8001 -torrent=torrent/puppy.torrent -file=out.jpg -debug=Status -persister=download_progress
• go run main.go -client -port=8002 -torrent=torrent/puppy.torrent -seed=seed/puppy.jpg -debug=Status