[tahoe-dev] [tahoe-lafs] #698: corrupted file displayed to user after failure to download followed by retry

[tahoe-lafs]

#698: corrupted file displayed to user after failure to download followed by
retry
--------------------------+-------------------------------------------------
 Reporter:  zooko         |           Owner:       
     Type:  defect        |          Status:  new  
 Priority:  critical      |       Milestone:  1.5.0
Component:  code-network  |         Version:  1.4.1
 Keywords:  integrity     |   Launchpad_bug:       
--------------------------+-------------------------------------------------

Comment(by zooko):

 By the way, the client doing the fetch was Firefox 3.5 beta 4 -- more
 details in the original report.  It's the package named "firefox-3.5" in
 Ubuntu Jaunty.

 Also, Brian, what do you think about the fact that there was no download
 step after the

 {{{
 09:47:10 07-May-2009    retrieve        6s64wyhfbm7yxb5cwzqblnndpe      No
 2.0kB   100.0%          Done
 09:47:10 07-May-2009    mapupdate MODE_READ     6s64wyhfbm7yxb5cwzqblnndpe
 No      -NA-    100.0%  Done
 }}}

 When I reloaded, but there was a download step after those two steps when
 I initially loaded?  This means the client (Firefox-3.5b4 web browser)
 didn't actually fetch the contents of my blog when I hit "Reload" and
 instead just spewed that messed-up page (attached as "wiki.html.bz2"),
 right?  In that case the "displaying corrupt page" is actually Firefox's
 problem (although as David-Sarah Hopwood pointed out
 [http://allmydata.org/pipermail/tahoe-dev/2009-May/001724.html on the
 mailing list], the way that Tahoe commits to a 200 success code before
 completely downloading the file means this can always happen by accident).

 Certainly ''something'' that Tahoe did was unusual, see the attached file
 {{{incident-2009-05-07-094319-jg54cni.flog.bz2}}}, which, when viewed with
 {{{flogtool web-viewer incident-2009-05-07-094319-jg54cni.flog.bz2}}}
 shows this among other things:

 {{{
 # Incident Triggers:

     * 09:43:19.240 [31906]: SCARY <CiphertextDownloader
 #14>(lxershd2xflh): download failed! FAILURE:

       [CopiedFailure instance: Traceback from remote host -- Traceback
 (most recent call last):
       Failure: twisted.internet.defer.FirstError:
 FirstError(<twisted.python.failure.Failure <class
 'foolscap.ipb.DeadReferenceError'>>, 2)
       ]

       [INCIDENT-TRIGGER]
 }}}

-- 
Ticket URL: <http://allmydata.org/trac/tahoe/ticket/698#comment:2>
tahoe-lafs <http://allmydata.org>
secure decentralized file storage grid