Version 77 (modified by zooko, at 2010-03-16T16:21:12Z) (diff)

edit to RAIC

Tahoe-LAFS Summer-of-Code Projects

This page contains specific suggestions for projects we would like to see in the Summer of Code. Note that they vary a lot in required skills and difficulty. We hope to get applications with a broad spectrum.

If you are interested in working on any of these projects, please contact the Mentors listed at the bottom of the page.

In addition, you may wish to discuss your proposal on IRC -- join us on #tahoe-lafs on

We encourage you to come up with your own suggestions, if you cannot find a suitable project here. You can find more project ideas by exploring the issue tracker. Especially see tickets labelled 'gsoc' (developers: please add this label to any tickets that might make a good GSoC project).

Deadlines and directions for students' applications to the Google Summer-of-Code can be found on the Google pages.

Redundant Array of Independent CloudsMedium
Share MigrationMedium

Redundant Array of Independent Clouds

Project summary:

  • Estimated difficulty: Medium

Add backends to the storage servers so that they store their shares on a cloud storage system instead of on their local filesystem. This means that you can get all of the availability and scalability of services such as Amazon S3 or Rackspace CloudFiles? combined with the security properties of Tahoe-LAFS. See the RAIC diagram. For details read ticket #999 which including pointers to the relevant source code and instructions on how to begin writing the code.

Share Migration

Project summary:

  • Estimated difficulty: Medium

When uploading a file to a grid, Tahoe-LAFS will make sure that the file is healthy (a good discussion of what healthy means is found in #778) before reporting that the file is uploaded successfully. Tools to effectively maintain file health (or to adapt to new definitions of health) aren't quite complete, however -- our users have had several use cases that aren't easily addressed with what we have. Students taking this project would be building tools to address those use cases.

A good starting point would be to become familiar with how files are placed on a grid. architecture.txt, file-encoding.txt, mutable.txt, the immutable file upload code, and the mutable file upload code are good places to do that. Also, you might want to look at the storage server code to understand that better. Some good tickets to start looking at are #699, #543, and #232; you'll find that those link to other tickets.

There are many ways to help address these issues. Some ideas:

  • Alter the CLI and the WUI to give users the ability to rebalance files that they've uploaded already. (#699)
  • Build tools that allow node administrators to moves shares around a grid (#543, #864)
  • Alter Tahoe-LAFS to rebalance mutable files when uploading a new version of them. (#232)

Any one of these projects is probably too small to fill a summer, but combined they would be a big usability improvement for Tahoe-LAFS.

Depending on how you address this, this is tightly integrated with ideas of file health and accounting, so prospective students would do well to explore those open issues, too. A good accounting jumping-off point is #666. A good jumping-off point for health is #778.


Who is willing to spend about five hours a week (estimated) helping a student do it right?

Zooko Wilcox-O'Hearn (Python/C/C++/JavaScript, cryptography)
  • Jack Lloyd (C/C++/Python, cryptography)
  • David-Sarah Hopwood (david-sarah at (Python/C/JavaScript, SFTP frontend, security+cryptography)

This page was modelled on the NetBSD Summer-of-Code page.