For example all the SocketServer or xmlrpclib >> abstractions close the sockets automatically. > > $ grep __del__ /usr/lib64/python2.7/SocketServer.py > $ grep __del__ /usr/lib64/python2.7/xmlrpclib.py > $ grep __del__ /usr/lib64/python2.7/SimpleXMLRPCServer.py
I did not say they are using __del__. I was merely pointing out that not cleaning after yourself violates the rule of the least surprise in Python. Because (almost) all higher level objects in the standard library avoid the need for explicit close call. > I disagree, __del__ cannot be implemented properly on python 2. > It is possible to close stuff automatically only in a c extension. Yes, you need to be careful and you might get into trouble because of exception handling, but the simple cases where you catch everything and delete self should be working just fine. > Trying to implement will lead to endless troubles. Any examples? (except __init__ not called and exception handling). Martin On Wed, May 25, 2016 at 12:21 PM, Nir Soffer <[email protected]> wrote: > On Wed, May 25, 2016 at 12:18 PM, Martin Sivak <[email protected]> wrote: >>> but it should >>> not try to implement __del__ - we had lot of trouble with such code in vdsm. >> >> Del is perfectly fine if done properly. Python objects should really >> clean after themselves. It is common to abstract the user from the low >> level networking code. For example all the SocketServer or xmlrpclib >> abstractions close the sockets automatically. > > $ grep __del__ /usr/lib64/python2.7/SocketServer.py > $ grep __del__ /usr/lib64/python2.7/xmlrpclib.py > $ grep __del__ /usr/lib64/python2.7/SimpleXMLRPCServer.py > >> The same is true about >> file objects (closed when garbage collected). > > This is implemented as C extension, not using __del__. > >> >> Context manager can (and should if possible) be used to handle >> exceptions properly and to allow better control, but the default >> behavior should still close the resources during __del__ too. > > I disagree, __del__ cannot be implemented properly on python 2. > It is possible to close stuff automatically only in a c extension. > Trying to implement will lead to endless troubles. > > Nir > >> >> Martin >> >> >> On Mon, May 23, 2016 at 2:57 PM, Nir Soffer <[email protected]> wrote: >>> On Mon, May 23, 2016 at 3:46 PM, Martin Sivak <[email protected]> wrote: >>>>> Explicit close is required. >>>>> >>>>> You should ensure that all resources are released using try finally. >>>> >>>> Not according to the code Simone found. The close is called by the >>>> __del__ method explicitly. And Python is no C, we should really behave >>>> "nice" by default. >>> >>> No, the code you found is misguided attempt and should be deleted from vdsm. >>> >>> The jsonrpc client can provide a context manger to help you close it, >>> but it should >>> not try to implement __del__ - we had lot of trouble with such code in vdsm. >>> >>> You must close the client explicitly when you are done. >>> >>> Nir >>> >>>> >>>> Martin >>>> >>>> On Mon, May 23, 2016 at 2:40 PM, Nir Soffer <[email protected]> wrote: >>>>> On Mon, May 23, 2016 at 11:15 AM, Martin Sivak <[email protected]> wrote: >>>>>> Hi, >>>>>> >>>>>>> I know that we reconnect several times during hosted engine process. Do >>>>>>> we >>>>>>> close client when it is not used anymore? >>>>>> >>>>>> No, we are not closing it according to Simone, shouldn't it be >>>>>> released automatically? We are using Python after all.. explicit close >>>>>> is not exactly common there. >>>>> >>>>> Explicit close is required. >>>>> >>>>> You should ensure that all resources are released using try finally. >>>>> >>>>> Nir >>>>> >>>>>> >>>>>> Martin >>>>>> >>>>>> On Mon, May 23, 2016 at 8:55 AM, Piotr Kliczewski <[email protected]> >>>>>> wrote: >>>>>>> Sandro, >>>>>>> >>>>>>> I know that we reconnect several times during hosted engine process. Do >>>>>>> we >>>>>>> close client when it is not used anymore? >>>>>>> >>>>>>> Please provide lsof for the process and the log. >>>>>>> >>>>>>> Thanks, >>>>>>> Piotr >>>>>>> >>>>>>> On Mon, May 23, 2016 at 8:42 AM, Sandro Bonazzola <[email protected]> >>>>>>> wrote: >>>>>>>> >>>>>>>> MainThread::WARNING::2016-05-23 >>>>>>>> 07:09:38,629::hosted_engine::480::ovirt_hosted_engine_ha.agent.hosted_engine.HostedEngine::(start_monitoring) >>>>>>>> Unexpected error >>>>>>>> Traceback (most recent call last): >>>>>>>> File >>>>>>>> "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/agent/hosted_engine.py", >>>>>>>> line 444, in start_monitoring >>>>>>>> self._initialize_vdsm() >>>>>>>> File >>>>>>>> "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/agent/hosted_engine.py", >>>>>>>> line 635, in _initialize_vdsm >>>>>>>> timeout=envconstants.VDSCLI_SSL_TIMEOUT >>>>>>>> File >>>>>>>> "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/lib/util.py", >>>>>>>> line >>>>>>>> 187, in connect_vdsm_json_rpc >>>>>>>> requestQueue=requestQueue, >>>>>>>> File "/usr/lib/python2.7/site-packages/vdsm/jsonrpcvdscli.py", line >>>>>>>> 222, >>>>>>>> in connect >>>>>>>> responseQueue) >>>>>>>> File "/usr/lib/python2.7/site-packages/vdsm/jsonrpcvdscli.py", line >>>>>>>> 212, >>>>>>>> in _create >>>>>>>> lazy_start=False) >>>>>>>> File "/usr/lib/python2.7/site-packages/yajsonrpc/stompreactor.py", >>>>>>>> line >>>>>>>> 576, in StandAloneRpcClient >>>>>>>> reactor = Reactor() >>>>>>>> File "/usr/lib/python2.7/site-packages/yajsonrpc/betterAsyncore.py", >>>>>>>> line 200, in __init__ >>>>>>>> self._wakeupEvent = AsyncoreEvent(self._map) >>>>>>>> File "/usr/lib/python2.7/site-packages/yajsonrpc/betterAsyncore.py", >>>>>>>> line 164, in __init__ >>>>>>>> map=map >>>>>>>> File "/usr/lib64/python2.7/asyncore.py", line 650, in __init__ >>>>>>>> self.set_file(fd) >>>>>>>> File "/usr/lib64/python2.7/asyncore.py", line 657, in set_file >>>>>>>> self.socket = file_wrapper(fd) >>>>>>>> File "/usr/lib64/python2.7/asyncore.py", line 616, in __init__ >>>>>>>> self.fd = os.dup(fd) >>>>>>>> OSError: [Errno 24] Too many open files >>>>>>>> >>>>>>>> Simone, Rafael, Piotr, Martin, can you please investigate? >>>>>>>> >>>>>>>> vdsm-yajsonrpc-4.18.0-16.git51df339.el7.centos.noarch >>>>>>>> >>>>>>>> ovirt-hosted-engine-ha-2.0.0-0.2.master.20160520143206.20160520143149.gita012f18.el7.noarch >>>>>>>> >>>>>>>> -- >>>>>>>> Sandro Bonazzola >>>>>>>> Better technology. Faster innovation. Powered by community >>>>>>>> collaboration. >>>>>>>> See how it works at redhat.com >>>>>>> >>>>>>> >>>>>> _______________________________________________ >>>>>> Devel mailing list >>>>>> [email protected] >>>>>> http://lists.ovirt.org/mailman/listinfo/devel _______________________________________________ Devel mailing list [email protected] http://lists.ovirt.org/mailman/listinfo/devel
