[Soap-Python] rpclib - very strange problem

azurIt azurit at pobox.sk
Tue Dec 6 19:20:19 CET 2011 

little more info:
 - the process which gets crazy is the one which was used as last (so, when i set wsgi to use only one process, 100% of requests are invalid)
 - upgrading mod_wsgi to the newest version didn't fix anything

Burak, are you 100% sure this can't be rpclib problem ?



______________________________________________________________
> Od: "Burak Arslan" <burak.arslan at arskom.com.tr>
> Komu: azurIt <azurit at pobox.sk>
> Dátum: 06.12.2011 18:52
> Predmet: Re: [Soap-Python] rpclib - very strange problem
>
> CC: soap at python.org
>On 12/06/11 19:48, azurIt wrote:
>> Burak, i got something!! :) i'm running two wsgi processes for my wsgi application (via mod_wsgi). invalid result is always returned by first of them and valid result is always returned by the second (until i restart wsgi app). this is why every second request gets crazy (there's a 50% chance). now why is this happening ? some kind of desynchronization between processes ?
>>
>
>ah, now it makes more sense. i'm not familiar with mod_wsgi, but i don't
>think mod_wsgi processes share information one way or the other. are you
>sure both initialize correctly?
>
>why not use twisted, cherrypy or any other pure-python http solution and
>use apache as a reverse-proxy?
>
>burak
>
>> ______________________________________________________________
>>> Od: "azurIt" <azurit at pobox.sk>
>>> Komu: <soap at python.org>
>>> Dátum: 06.12.2011 18:43
>>> Predmet: Re: [Soap-Python] rpclib - very strange problem
>>>
>>> cool, it's working now. problem is that traceback for both cases (where result is ok and is not ok) looks the same:
>>>
>>>
>>> File "/usr/lib/python2.5/site-packages/rpclib-2.4.1_beta-py2.5.egg/rpclib/server/wsgi.py", line 168, in __call__
>>>  return self.__handle_rpc(req_env, start_response)
>>> File "/usr/lib/python2.5/site-packages/rpclib-2.4.1_beta-py2.5.egg/rpclib/server/wsgi.py", line 239, in __handle_rpc
>>>  self.get_out_object(ctx)
>>> File "/usr/lib/python2.5/site-packages/rpclib-2.4.1_beta-py2.5.egg/rpclib/server/_base.py", line 73, in get_out_object
>>>  self.app.process_request(ctx)
>>> File "/usr/lib/python2.5/site-packages/rpclib-2.4.1_beta-py2.5.egg/rpclib/application.py", line 102, in process_request
>>>  ctx.out_object = self.call_wrapper(ctx)
>>> File "/usr/lib/python2.5/site-packages/rpclib-2.4.1_beta-py2.5.egg/rpclib/_base.py", line 190, in __setattr__
>>>  object.__setattr__(self, k, v)
>>> File "/usr/lib/python2.5/site-packages/rpclib-2.4.1_beta-py2.5.egg/rpclib/_base.py", line 51, in set_out_object
>>>  traceback.print_stack()
>>>
>>>
>>> i can only see rpclib code, not mine. any hints how can i show something more ? thnx!!!
>>>
>>> azur
>>>
>>>
>>> ______________________________________________________________
>>>> Od: "Burak Arslan" <burak.arslan at arskom.com.tr>
>>>> Komu: azurIt <azurit at pobox.sk>
>>>> Dátum: 06.12.2011 17:53
>>>> Predmet: Re: [Soap-Python] rpclib - very strange problem
>>>>
>>>> CC: soap at python.org
>>>> On 12/06/11 18:51, Burak Arslan wrote:
>>>>> On 12/06/11 18:46, azurIt wrote:
>>>>>> Sorry for bordering, i would write/fix it by myself but i don't fully understand your code. This is what it is doing now:
>>>>> you should read about the property built-in.
>>>>>
>>>>>> Traceback (most recent call last):
>>>>>>   File "/usr/lib/python2.5/site-packages/rpclib-2.4.1_beta-py2.5.egg/rpclib/application.py", line 102, in process_request
>>>>>>     ctx.out_object = self.call_wrapper(ctx)
>>>>>>   File "/usr/lib/python2.5/site-packages/rpclib-2.4.1_beta-py2.5.egg/rpclib/_base.py", line 191, in __setattr__
>>>>>>     raise ValueError("use the udc member for storing arbitrary data "
>>>>>> ValueError: use the udc member for storing arbitrary data in the method context
>>>>> set self.frozen to false in the constructor's last line.
>>>> or rather add self.__out_object=None to the ctor.
>>>>
>>>>> i'd forgotten about the __getattr__ in that class, you can modify that
>>>>> as well if you understand better what that does.
>>>>>
>>>>> burak
>>>>>> ______________________________________________________________
>>>>>>> Od: "Burak Arslan" <burak.arslan at arskom.com.tr>
>>>>>>> Komu: azurIt <azurit at pobox.sk>
>>>>>>> Dátum: 06.12.2011 17:19
>>>>>>> Predmet: Re: [Soap-Python] rpclib - very strange problem
>>>>>>>
>>>>>>> CC: soap at python.org
>>>>>>> On 12/06/11 18:14, azurIt wrote:
>>>>>>>> Burak,
>>>>>>>>
>>>>>>>> can you, please, help me with this a little more? Where exactly should i put that code? Into _base.py file? Thank you!
>>>>>>>>
>>>>>>>> azur
>>>>>>> yes, in the MethodContext class, like so:
>>>>>>>
>>>>>>> class MethodContext(object):
>>>>>>>    def get_out_object(self):
>>>>>>>       return self.__out_object
>>>>>>>
>>>>>>>    def set_out_object(self, what):
>>>>>>>       import traceback
>>>>>>>       traceback.print_stack()
>>>>>>>       self.__out_object = what
>>>>>>>
>>>>>>>    out_object = property(get_out_object, set_out_object)
>>>>>>>
>>>>>>>    # (...)
>>>>>>>    # rest of the class definition
>>>>>>>
>>>>>>> hth,
>>>>>>> burak
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> ______________________________________________________________
>>>>>>>>> Od: "Burak Arslan" <burak.arslan at arskom.com.tr>
>>>>>>>>> Komu: azurIt <azurit at pobox.sk>
>>>>>>>>> Dátum: 05.12.2011 18:33
>>>>>>>>> Predmet: Re: [Soap-Python] rpclib - very strange problem
>>>>>>>>>
>>>>>>>>> CC: soap at python.org
>>>>>>>>> On 12/05/11 17:55, azurIt wrote:
>>>>>>>>>> Any hints ? :)
>>>>>>>>> patch rpclib code to instrument the out_object attribute. have the
>>>>>>>>> instrumentation spit tracebacks on assignments. that way you'll be able
>>>>>>>>> to track where that strange value comes from.
>>>>>>>>>
>>>>>>>>> off the top of my head, add these to the MethodContext class:
>>>>>>>>>
>>>>>>>>> def get_out_object(self):
>>>>>>>>>    return self.__out_object
>>>>>>>>>
>>>>>>>>> def set_out_object(self, what):
>>>>>>>>>    import traceback
>>>>>>>>>    traceback.print_stack()
>>>>>>>>>    self.__out_object = what
>>>>>>>>>
>>>>>>>>> out_object = property(get_out_object, set_out_object)
>>>>>>>>>
>>>>>>>>> every _second_ request? heh, that's fun :)
>>>>>>>>>
>>>>>>>>> good luck,
>>>>>>>>> burak
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>> azur
>>>>>>>>>> _______________________________________________
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