[tahoe-lafs-trac-stream] [tahoe-lafs] #1870: leasedb: performance regression

[tahoe-lafs]

#1870: leasedb: performance regression
-------------------------------------------------+-------------------------
 Reporter:  davidsarah                           |          Owner:
     Type:  defect                               |  davidsarah
 Priority:  normal                               |         Status:  new
Component:  unknown                              |      Milestone:
 Keywords:  leasedb performance regression       |  undecided
  sqlite                                         |        Version:  1.9.2
                                                 |  Launchpad Bug:
-------------------------------------------------+-------------------------
 The [https://github.com/davidsarah/tahoe-lafs/commits/1818-leasedb
 1818-leasedb] branch has a performance regression that shows up when
 running the test suite -- in fact, the test suite is not able to pass at
 the moment purely due to timeouts.

 Since the regression does ''not'' show up when using {{{make tmpfstest}}}
 (which uses a memory-based tmpfs filesystem rather than disk), my
 tentative conclusion is that it is due to the latency of leasedb database
 syncs. There are currently many redundant syncs due to every SQL
 query/update being in a separate transaction, and due to there being more
 SQL operations than necessary per request. We could also use a more
 relaxed consistency mode, if that is safe.

-- 
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1870>
tahoe-lafs <https://tahoe-lafs.org>
secure decentralized storage