mirror of
https://github.com/tahoe-lafs/tahoe-lafs.git
synced 2024-12-27 00:21:07 +00:00
28 lines
1.1 KiB
Plaintext
28 lines
1.1 KiB
Plaintext
The lossmodel.lyx file is the source document for an in-progress paper
|
|
that analyzes the probability of losing files stored in a Tahoe-LAFS
|
|
file store under various scenarios. It describes:
|
|
|
|
1. How to estimate peer reliabilities, based on peer MTBF failure
|
|
data.
|
|
|
|
2. How to compute file loss probabilities, based on a given set of
|
|
shares stored on peers with estimated reliabilities. The peer
|
|
reliabilities do not have to be uniform, and the model takes into
|
|
account the file repair process.
|
|
|
|
3. How to estimate Tahoe parameters for k (shares needed), n (shares
|
|
distributed) and A (repair interval) to achieve a file reliability
|
|
target.
|
|
|
|
4. How to compute the estimated repair cost over time, discounted at
|
|
a fixed rate, of maintaining a file for a time period T.
|
|
|
|
Future work will also address the latter three issues in the context
|
|
of "non-aggressive" repair, where repair will only be performed if
|
|
too many shares are lost, and it will also extend the repair cost
|
|
estimation model to suggest cost functions appropriate for common
|
|
network architectures.
|
|
|
|
A PDF of the current version of the file may be downloaded from:
|
|
|
|
http://willden.org/~shawn/lossmodel.pdf |