[tahoe-lafs-trac-stream] [tahoe-lafs] #1467: nondeterministic test failure in allmydata.test.test_system.SystemTest.test_filesystem because the Welcome page says "Connected to helper: no" when the test expected "yes"

[tahoe-lafs]

#1467: nondeterministic test failure in
allmydata.test.test_system.SystemTest.test_filesystem because the Welcome
page says "Connected to helper: no" when the test expected "yes"
----------------------------+----------------------------
     Reporter:  davidsarah  |      Owner:  warner
         Type:  defect      |     Status:  closed
     Priority:  normal      |  Milestone:  undecided
    Component:  code        |    Version:  1.8.2
   Resolution:  fixed       |   Keywords:  test heisenbug
Launchpad Bug:              |
----------------------------+----------------------------
Changes (by Brian Warner <warner@…>):

 * status:  new => closed
 * resolution:   => fixed


Comment:

 In [changeset:5579/trunk]:
 {{{
 #!CommitTicketReference repository="trunk" revision="5579"
 test/common.py: fix race condition waiting for the helper connection

 The wait_for_connections() method, which is used at the start of
 test_system to make sure that all the clients are connected to all the
 servers, did not also wait for clients to be connected to their Helpers.
 Every once in a while, the helper connection would take a bit longer,
 and then
 test_system.SystemTest.test_filesystem._test_web._got_welcome_helper
 would fail, because we'd check for a helper connection before it was
 ready.

 The fix is to modify wait_for_connections's polling predicate to look
 for helper connections (if configured) as well as the regular
 introducer- and server- connections.

 Tested by temporarily adding a large (30s) delay to the connectTo() call
 in Uploader.startService, simulating a long helper
 connection-establishment delay. This makes the test fail consistently.
 Then I fixed wait_for_connections(), and the test passed (slowly). Then
 I removed the delay.

 Closes #1467
 }}}

-- 
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1467#comment:8>
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