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[Imported from Trac: page AccountingDesign, version 7]

warner 2008-07-01 00:25:59 +00:00
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commit ddbc56b1b3
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AccountingDesign.md

@ -168,3 +168,46 @@ authority is being delegated. The fields we'll define for v1 are:
exactly one lease on the resulting share.
* other attenuations: TBD (things like until=, SI=, UEBhash=, operation=,
max-size=)
## Lease Tables
The server will maintain a "lease table", to provide efficient lookup by
account. This primarilly supports the "how much is Bob using?" question, and
will (in a future version) support the reconcilliation operation.
To avoid revising the v1 share file format (which only offers a 4-byte
"ownerid" field), the server maintains a second table that maps from these
4-byte "pubkeyid" numbers to the full pubkey, and puts an additional column
in the lease table to map from pubkey to pubkeyid.
* `NODEDIR/accounting/pubkeyids`: 32 bytes per pubkeyid, assigned
sequentially. `pubkey[4]` is the 32 bytes at offset 4*32.
* `NODEDIR/accounting/usage/base32(PUBKEY)`: one file per pubkey.
Contents are:
* bytes 0-3: pubkeyid
* bytes 4-11: total size
* bytes 12-19: total number of files
* (deferred until v1.3): reconcilliation list (variable length list of SIs)
The lease table may be switched to use an intermediate prefix directory
later, to make lookup more efficient (some native filesystems get slow when
you put thousands or tens-of-thousands of files in a single directory).
For ext3, a 300k-entry lease table is likely to use 1.2GB . For something
like reiserfs3 that can pack small files, it might take juse 18MB. A SQL
representation would probably be fairly compact too.
### Pet Name Table
The "Usage/Aggregator" component (described below) can display a "pet name"
along with each key, to make the results more meaningful ("Bob using 73MB"
instead of "pubkey j7sta2uvcr345znqwfwlxitnii is using 73MB"). This is more
likely to be used by the friendnet case than the commercial grid (in which
this functionality will most likely exist in an external database). The "pet
name table" may contain other information about the public keys to which
storage has been delegated.
* `NODEDIR/?/petnames`: one line per pubkey, each line is:
* `base32(pubkey): PETNAME\n`
* if multiple pubkeys map to the same pet name, their usage will be added
together at display time.