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

[tahoe-lafs]

#1870: leasedb: performance regression
-------------------------+-------------------------------------------------
     Reporter:           |      Owner:  daira
  davidsarah             |     Status:  assigned
         Type:  defect   |  Milestone:  1.11.0
     Priority:  normal   |    Version:  1.9.2
    Component:  code-    |   Keywords:  leasedb performance regression
  storage                |  sqlite
   Resolution:           |
Launchpad Bug:           |
-------------------------+-------------------------------------------------

Comment (by zooko):

 Next, I extended fdleakfinder
 [https://github.com/zooko/fdleakfinder/commit/e26db960e8d1674cf5fcc0152b096a64bea03004
 to print out a histogram of how many times each filename was opened] and
 ran that on {{{allmydata.test.test_cli.Backup.test_backup}}}. This showed
 that 1819 branch is ''not'' opening sqlite db files very often in this
 test (just once each), but that it is opening the share files a lot more
 often:
 {{{
 zooko at spark ~/playground/tahoe-lafs $ tail log.master-
 fdleakfinderout-2.txt
   73),
 ('"cli/Backup/backup/servers/k6vb2bpd/storage/shares/eq/eqbt53qswmzlvr5r6tfupcfyam/3",
 O_RDONLY',
   73),
 ('"cli/Backup/backup/servers/rvsry4kn/storage/shares/eq/eqbt53qswmzlvr5r6tfupcfyam/6",
 O_RDONLY',
   73),
 ('"cli/Backup/backup/servers/xgru5adv/storage/shares/eq/eqbt53qswmzlvr5r6tfupcfyam/9",
 O_RDONLY',
   73),
 ('"cli/Backup/backup/servers/ysbz4st7/storage/shares/eq/eqbt53qswmzlvr5r6tfupcfyam/5",
 O_RDONLY',
   73),
  ('"/dev/urandom", O_RDONLY', 236)]
 zooko at spark ~/playground/tahoe-lafs $ tail log.1819-cloud-merge-
 opensource-fdleakfinderout-2.txt
   108),
 ('"cli/Backup/backup/servers/k6vb2bpd/storage/shares/ef/efe5w4eitpntre3p4zmbbqy7cy/0",
 O_RDONLY',
   108),
 ('"cli/Backup/backup/servers/rvsry4kn/storage/shares/ef/efe5w4eitpntre3p4zmbbqy7cy/6",
 O_RDONLY',
   108),
 ('"cli/Backup/backup/servers/xgru5adv/storage/shares/ef/efe5w4eitpntre3p4zmbbqy7cy/2",
 O_RDONLY',
   108),
 ('"cli/Backup/backup/servers/ysbz4st7/storage/shares/ef/efe5w4eitpntre3p4zmbbqy7cy/4",
 O_RDONLY',
   108),
  ('"/dev/urandom", O_RDONLY', 136)]
 }}}

-- 
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1870#comment:17>
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