Open Stack

You can also use the eventlet backdoor functionality already in Nova [1]

Just set the backdoor_port flag and telnet to it, then use it as a
remote debugger using the following commands:

	fo -- Find objects of a particular instance type
        pgt -- Print the greenthreads stacks

For more on debugging eventlet with backdoor:

http://eventlet.net/doc/modules/backdoor.html

Best,
-jay

[1]
https://github.com/openstack/nova/blob/master/nova/common/eventlet_backdoor.py

On 08/24/2012 09:34 AM, Yong Sheng Gong wrote:
> Another way is to modify monkey_patch() to monkey_patch(thread=False) in
> single process mode. (nova-scheduler is a single processmode itself.)
> 
> Then u can debug it in pydev as usual.
> 
> 
> -----Rafael Durán Castañeda <rafadurancastaneda at gmail.com> wrote: -----
> To: openstack-dev at lists.openstack.org
> From: Rafael Durán Castañeda <rafadurancastaneda at gmail.com>
> Date: 08/22/2012 07:38PM
> Subject: Re: [openstack-dev] Problem with debugging program having
> eventlet.monkey_patch() code
> 
> On 08/21/2012 03:49 PM, michel.gauthier at bull.net wrote:
>> I have installed winpdb, but I have still a problem while debugging
>> nova-scheduler service :
>>
>> on eventlet.monkey_patch()instruction, the debugger get the following
>> exception :
>>
>>
>> on winpdb GUI session ( launched thru : winpdb command and then
>> atteched to the debugee session)
>> Exception in thread Thread-57:
>> Traceback (most recent call last):
>>   File "/usr/lib/python2.7/threading.py", line 551, in __bootstrap_inner
>>     self.run()
>>   File "/usr/lib/python2.7/threading.py", line 504, in run
>>     self.__target(*self.__args, **self.__kwargs)
>>   File "/usr/local/lib/python2.7/dist-packages/rpdb2.py", line 10790,
>> in __event_monitor_proc
>>     (n, sel) =
>> self.getSession().getProxy().wait_for_event(PING_TIMEOUT,
>> self.m_remote_event_index)
>>   File "/usr/lib/python2.7/xmlrpclib.py", line 1224, in __call__
>>     return self.__send(self.__name, args)
>>   File "/usr/local/lib/python2.7/dist-packages/rpdb2.py", line 9520,
>> in __request
>>     raise _e
>> RuntimeError: cannot release un-acquired lock
>>
>>
>> on winpdb debugee session (launched thru : winpdb -d
>> /usr/bin/nova-scheduler --flagfile=/etc/nova/nova.conf command)
>> Exception in thread __worker_target:
>> Traceback (most recent call last):
>>   File "/usr/lib/python2.7/threading.py", line 551, in __bootstrap_inner
>>     self.run()
>>   File "/usr/local/lib/python2.7/dist-packages/rpdb2.py", line 4574,
>> in run
>>     threading.Thread.run(self)
>>   File "/usr/lib/python2.7/threading.py", line 504, in run
>>     self.__target(*self.__args, **self.__kwargs)
>>   File "/usr/local/lib/python2.7/dist-packages/rpdb2.py", line 9361,
>> in __worker_target
>>     self.m_lock.release()
>>   File "/usr/lib/python2.7/threading.py", line 142, in release
>>     raise RuntimeError("cannot release un-acquired lock")
>> RuntimeError: cannot release un-acquired lock
>>
>>
>> Help for a solution.
>>
>>
>>
>>
>>
>> De :        Michael J Fork <mjfork at us.ibm.com>
>> A :        OpenStack Development Mailing List
>> <openstack-dev at lists.openstack.org>
>> Date :        17/08/2012 15:03
>> Objet :        Re: [openstack-dev] Problem with debugging program    
>>    having        eventlet.monkey_patch() code
>> ------------------------------------------------------------------------
>>
>>
>>
>> We have found that Winpdb (_http://winpdb.org/_- platform independent
>> despite Win in the name) works well with multi-threaded Python.  While
>> using PyDev for development, run Winpdb as a remote debugger for the
>> multithreaded service.  Flow is like this:
>>
>> Launch Winpdb GUI
>> # winpdb
>>
>> Start Debugging
>> # cd /home/openstack-dev/workspace/nova/bin
>> # winpdb -d -r <file_to_debug>
>> Set Password: openstack
>>
>> Attach to Process
>> 1) In Winpdb GUI, select File -> Attach
>> 2) Enter password from step 4, should display files associated with
>> that password
>> 3) Select process/file then select OK
>>  
>> To Stop Debug or Make Changes and Restart
>> 1) File -> Stop to detach current debugger
>> 2) Make changes in Eclipse and Save (make sure development user has
>> write privileges to repository)
>> 3) kill and restart winpdb debugging process started above
>> 4) Re-attach to the process in the Winpdb GUI
>>
>> Michael
>>
>> -------------------------------------------------
>> Michael Fork
>> Cloud Architect, Emerging Solutions
>> IBM Systems & Technology Group
>>
>> michel.gauthier at bull.net wrote on 08/17/2012 07:59:18 AM:
>>
>> > From: michel.gauthier at bull.net
>> > To: openstack-dev at lists.openstack.org,
>> > Date: 08/17/2012 08:02 AM
>> > Subject: [openstack-dev] Problem with debugging program having
>> > eventlet.monkey_patch() code
>> >
>> > Hi all,
>> > I want to debug nova-scheduler service (Essex version)  code with
>> > Eclipse->Pydev->Debug Configuration.
>> > But when I launch it under Debug Configuration, I get the following
>> > error messages :
>> >
>> > pydev debugger: starting
>> > Traceback (most recent call last):
>> >   File "/usr/lib/python2.7/dist-packages/eventlet/hubs/hub.py", line
>> > 336, in fire_timers
>> >     timer()
>> >   File "/usr/lib/python2.7/dist-packages/eventlet/hubs/timer.py",
>> > line 56, in __call__
>> >     cb(*args, **kw)
>> >   File "/usr/lib/python2.7/dist-packages/eventlet/semaphore.py",
>> > line 95, in _do_acquire
>> >     waiter.switch()
>> > error: cannot switch to a different thread
>> >
>> > and then, Pydev debugger does not work!
>> >
>> > In fact, these errors are due to the use of eventlet.monkey_patch()
>> inside
>> > nova-scheduler launcher (as well as inside other nova-* launchers).
>> >
>> > Do you have any ideas to resolve this problem?
>> >
>> > Thanks in advance._______________________________________________
>> > OpenStack-dev mailing list
>> > OpenStack-dev at lists.openstack.org
>> >
>> _http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev________________________________________________
>> OpenStack-dev mailing list
>> OpenStack-dev at lists.openstack.org
>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>>
>>
>>
>> _______________________________________________
>> OpenStack-dev mailing list
>> OpenStack-dev at lists.openstack.org
>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
> As a quick workaround you can change monkey patching at nova-scheduler
> script:
> 
>  eventlet.monkey_patch(thread=False)
> 
> HTH
> _______________________________________________
> OpenStack-dev mailing list
> OpenStack-dev at lists.openstack.org
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
> 
> 
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