[tahoe-lafs-trac-stream] [tahoe-lafs] #1646: nondeterministic failure of mydata.test.test_runner.RunNode.test_introducer

[tahoe-lafs]

#1646: nondeterministic failure of mydata.test.test_runner.RunNode.test_introducer
---------------------------------------+----------------------------
 Reporter:  davidsarah                 |          Owner:  davidsarah
     Type:  defect                     |         Status:  new
 Priority:  major                      |      Milestone:  undecided
Component:  code                       |        Version:  1.9.0
 Keywords:  test heisenbug introducer  |  Launchpad Bug:
---------------------------------------+----------------------------
 {{{allmydata.test.test_runner.RunNode.test_introducer}}} sometimes fails
 with the following error:
 {{{
   RunNode
     test_introducer ... Traceback (most recent call last):
   File "/home/bb-tahoe/bb-tahoe/sickness-
 openbsd-x86-py2.7/build/src/allmydata/test/test_runner.py", line 441, in
 _check_same_furl_and_port
     self.failUnlessEqual(self.furl, fileutil.read(INTRODUCER_FURL_FILE))
 twisted.trial.unittest.FailTest: not equal:
 a = ''
 b =
 'pb://w6x2bwklda63sm26ki7tqhieri5fl3fz@192.168.0.120:30549,127.0.0.1:30549/introducer\n'

 [FAIL]
 }}}

 I believe the problem is due to an incorrect assumption in the test, that
 {{{introducer.furl}}} will be written before {{{node.url}}}. In fact they
 may be written in either order, because the {{{init_introducer}}} method
 of [source:src/allmydata/introducer/server.py IntroducerNode] writes
 {{{introducer.furl}}} concurrently with the {{{init_web}}} method of the
 same class (indirectly) writing {{{node.url}}}.

 {{{test_runner.py}}} is prone to race conditions because we don't have a
 particularly reliable way to determine that a node has started, and so
 these tests rely on implementation details of when files ware created
 during the startup process.

-- 
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1646>
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