[tahoe-lafs-trac-stream] [tahoe-lafs] #1835: stop grovelling the whole storage backend looking for externally-added shares to add a lease to

[tahoe-lafs]

#1835: stop grovelling the whole storage backend looking for externally-added
shares to add a lease to
-------------------------+-------------------------------------------------
     Reporter:  zooko    |      Owner:
         Type:           |     Status:  new
  enhancement            |  Milestone:  undecided
     Priority:  normal   |    Version:  1.9.2
    Component:  code-    |   Keywords:  leases garbage-collection
  storage                |  accounting
   Resolution:           |
Launchpad Bug:           |
-------------------------+-------------------------------------------------

Comment (by davidsarah):

 Currently the server always does a list query to the backend. The leasedb
 allows us to skip that list query in the case where the share is present
 in the DB. If the leasedb is not authoritative, then we still do the query
 in the case where the share is not present in the DB, but this only
 prevents us from improving the latency of reporting that a server does
 ''not'' have a share. So, given that the downloader uses the first k
 servers to respond to a DYHB, it does not affect the performance of a
 (successful) download.

 Falling back to the list query when a share is not in the DB does increase
 complexity, though.

-- 
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1835#comment:3>
tahoe-lafs <https://tahoe-lafs.org>
secure decentralized storage