[tor-bugs] #2001 [Tor Relay]: Reachability test for ORPort doesn't complete with --enable-bufferevents set

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#2001: Reachability test for ORPort doesn't complete with --enable-bufferevents
set
-----------------------+----------------------------------------------------
 Reporter:  Sebastian  |          Owner:  nickm             
     Type:  defect     |         Status:  accepted          
 Priority:  major      |      Milestone:  Tor: 0.2.3.1-alpha
Component:  Tor Relay  |        Version:                    
 Keywords:             |         Parent:                    
   Points:             |   Actualpoints:                    
-----------------------+----------------------------------------------------

Comment(by Wawe):

 Replying to [comment:28 stars]:

 I encountered a possibly related problem with --enable-bufferevents.
 In my environment it seems that bootstrapping never succeeds when buffer
 events
 are used.

 The behaviour is similar to what stars described.

 Here are the results of a series of tests in which I altered
 --enable-bufferevents, the data directory, and
 TOR_LIBEVENT_TICKS_PER_SECOND
 found in src/common/compat_libevent.h.

 For the last few I documented the settings and whether bootstrapping
 succeeded
 to post it here:

 Here are the log files for the test cases listed below:
 http://www-public.rz.uni-duesseldorf.de/~marad002/tor_log/notice.log
 http://www-public.rz.uni-duesseldorf.de/~marad002/tor_log/debug.log

 1.  no buffer events                 : bootstrapping succeeds
 2.  enable buffer events, 1 tick/s   : bootstrapping succeeds
 3.  restart                          : bootstrapping succeeds
 4.  clean out data directory, restart: stuck at "Bootstrapped 25%: Loading
 networkstatus consensus."
 5.  restart                          : stuck at "Bootstrapped 25%: Loading
 networkstatus consensus."
 6.  clean out data directory, no buffer events                 :
 bootstrapping succeeds
 7.  restart                          : bootstrapping succeeds
 8.  enable buffer events, 100 tick/s : stuck at "Bootstrapped 85%:
 Finishing handshake with first hop."
 9.  clean out data directory, restart: stuck at "Bootstrapped 10%: Loading
 networkstatus consensus."
 10. no buffer events                 : bootstrapping succeeds
 11. enable buffer events, 100 tick/s : stuck at "Bootstrapped 85%:
 Finishing handshake with first hop."
 12. enable buffer events, 1 tick/s   : stuck at "Bootstrapped 85%:
 Finishing handshake with first hop."
 13. clear data directory, no buffer events                 : bootstrapping
 succeeds
 14. enable buffer events, 1 tick/s   : stuck at "Bootstrapped 90%:
 Establishing a Tor circuit."

 Note that it gets stuck earlier if there is no data directory.
 In all my testing there was only one situation in which bootstrapping
 succeeded
 with buffer events enabled, which was in 2. above. All previous attempts
 failed
 at some point.

 My own observations so far are these:
 When starting with an empty data directory, bootstrapping does not go
 beyond
 25%.
 When starting with a data directory created by a correctly working tor
 node
 (i.e. one with buffer events disabled) bootstrapping got stuck between
 80-90%. One time it even succeeded.

 I also tried upgrading to a later version of OpenSSL and libevent, but it
 did
 not have any effect. I still get the same behaviour with buffer events.


 tor commit: d120ee1c63ec52e23f24f3f4f9f80a9896381406
 OpenSSL version: 0.9.8g (and later 0.9.8n)
 libevent version: 2.0.10 stable
 Platform: Debian GNU/Linux, running in a VM
 uname -a: Linux oniontest 2.6.26-2-xen-686 #1 SMP Thu Jan 27 05:44:37 UTC
 2011 i686 GNU/Linux

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/2001#comment:46>
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