id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	launchpad_bug
468	design+build the Usage/Aggregator service	warner		"As part of the Accounting project, we'll be building a ""Usage"" service, which
will help keep track of how much space is used per account. Here are my notes
from last week:

   creating a Tahoe node with a storage server component creates a Usage
   component by default. You can also create a node with a Usage component
   but nothing else: we call this an Aggregator. The Usage component
   subscribes to any co-resident Storage component, and can also subscribe to
   other Storage services in other nodes. The Usage component provides a web
   interface (localhost:8124/usage) that provides different views of a table
   that shows usage (in bytes) per (server,account) pair. It also provides a
   sum across all servers. If the Usage component is only subscribing to a
   single storage server, the table will only have one column, and the sum
   will be the same as the table. It can also return information about just a
   subset of accounts (to return data in batches, since there might be a
   million accounts). The Usage component will consult an optional ""petname
   database"", which maps account to name. It will have an HTML table display,
   and a machine-readable JSON interface.

   Allmydata will run an Aggregator that subscribes to all prodnet storage
   servers. Peter's SQL database stuff will then make JSON queries of the
   aggregator to keep track of how much each customer is using.

   In a friendnet deployment, the storage server admin can use their local
   Usage service to find out how much each of their friends is using on that
   one server. If the friendnet members exchange Usage-subscription-FURLs
   symmetrically, they will be able to see how much each member is using
   across the whole friendnet.

   When we implement Invitations, the code that negotiates the invitation
   will populate the petname database.
"	enhancement	new	major	undecided	code-storage	1.1.0		accounting wui