This is a place to share our work on the Accounting task.

Accounting

Tahoe-1.1 is lacking a significant feature: the ability for the admin of a storage server to keep track of how much disk space is being used by various clients. Friendnet operators can use this information to see how much their friends are using (and perhaps ask them to use less). Commercial grid operators can use this to bill customers according to how much space they use, or to limit them to a pre-defined plan ("1GB maximum"). (related tickets: #119)

Tahoe needs better handling of disk-full situations (related tickets: #390), but this is a server-wide issue, whereas Accounting is specifically per-user.

Potential Requirements

Here is a list of potential requirements, in no particular order of when (or if) we actually need them to be completed:

1. only grant space to approved clients: "Larry the Leech" should not be able to upload files or cause existing files to be retained
2. be able to answer the question "How much space is Bob using?" 2a. asking this question about a single server (friendnet) 2b. asking this question system-wide: summed across all storage servers (commercial grid)
3. prior restraint: prevent Bob from consuming more than X bytes per server
4. disable a previously-allowed account / revocation
5. expiration: revoke permission after some amount of time, unless explicitly renewed
6. delegation: if Bob has permission, he can grant some to Little Bobby Junior 6a. subdivision / resellers : commercial grid operator grants space to a business partner 6b. repair caps: clients delegate limited upload authority to a repairer 6c. renewal cap: clients delegate lease-renewal authority 6d. helper: clients enable the helper to upload files for them
7. auditing: who owns this share, how did they get permission to upload it
8. reconcilliation / garbage collection : which shares does Bob own?

Immediate Goals

We've established a smaller set of goals for the next few releases:

• 1.2 (august 08):
  • be able to answer "how much does Bob store?"
  • deny service to Larry The Leech
  • enable accounting in both friendnet and commercial grids
  • enable accounting in webapi and helper interfaces

• 1.3 (september?)
  • be able to enumerate Bob's shares, for reconcilliation

• next after that
  • more generalized delegation