Open Stack

Certainly adding an explicit shutdown or terminate call to the driver
seems reasonable - a blueprint to this effect would be welcome.

On 7 April 2014 06:13, Deepak Shetty <dpkshetty at gmail.com> wrote:
> To add:
>     I was looking at Nova code and it seems there is a framework for cleanup
> using the terminate calls.. IIUC this works as libvirt calls terminate on
> Nova instance when the VM is shutting down/destroying, hence terminate seems
> to be a good place to do cleanup on Nova side.. something similar is missing
> on Cinder side and __del__ way of cleanup isn't working as I posted above.
>
>
> On Mon, Apr 7, 2014 at 10:24 AM, Deepak Shetty <dpkshetty at gmail.com> wrote:
>>
>> Duncan,
>>     Thanks for your response. Tho' i agree to what you said.. I am still
>> trying to understand why i see what i see .. i.e. why the base class
>> variables (_mount_shared) shows up empty in __del__
>> I am assuming here that the obj is not completely gone/deleted, so its
>> vars must still be in scope and valid.. but debug prints suggests the
>> otherwise :(
>>
>>
>> On Sun, Apr 6, 2014 at 12:07 PM, Duncan Thomas <duncan.thomas at gmail.com>
>> wrote:
>>>
>>> I'm not yet sure of the right way to do cleanup on shutdown, but any
>>> driver should do as much checking as possible on startup - the service
>>> might not have gone down cleanly (kill -9, SEGFAULT, etc), or
>>> something might have gone wrong during clean shutdown. The driver
>>> coming up should therefore not make any assumptions it doesn't
>>> absolutely have to, but rather should check and attempt cleanup
>>> itself, on startup.
>>>
>>> On 3 April 2014 15:14, Deepak Shetty <dpkshetty at gmail.com> wrote:
>>> >
>>> > Hi,
>>> >     I am looking to umount the glsuterfs shares that are mounted as
>>> > part of
>>> > gluster driver, when c-vol is being restarted or Ctrl-C'ed (as in
>>> > devstack
>>> > env) or when c-vol service is being shutdown.
>>> >
>>> > I tried to use __del__ in GlusterfsDriver(nfs.RemoteFsDriver) and it
>>> > didn't
>>> > work
>>> >
>>> > def __del__(self):
>>> >         LOG.info(_("DPKS: Inside __del__ Hurray!, shares=%s")%
>>> > self._mounted_shares)
>>> >         for share in self._mounted_shares:
>>> >             mount_path = self._get_mount_point_for_share(share)
>>> >             command = ['umount', mount_path]
>>> >             self._do_umount(command, True, share)
>>> >
>>> > self._mounted_shares is defined in the base class (RemoteFsDriver)
>>> >
>>> > ^C2014-04-03 13:29:55.547 INFO cinder.openstack.common.service [-]
>>> > Caught
>>> > SIGINT, stopping children
>>> > 2014-04-03 13:29:55.548 INFO cinder.openstack.common.service [-] Caught
>>> > SIGTERM, exiting
>>> > 2014-04-03 13:29:55.550 INFO cinder.openstack.common.service [-] Caught
>>> > SIGTERM, exiting
>>> > 2014-04-03 13:29:55.560 INFO cinder.openstack.common.service [-]
>>> > Waiting on
>>> > 2 children to exit
>>> > 2014-04-03 13:29:55.561 INFO cinder.openstack.common.service [-] Child
>>> > 30185
>>> > exited with status 1
>>> > 2014-04-03 13:29:55.562 INFO cinder.volume.drivers.glusterfs [-] DPKS:
>>> > Inside __del__ Hurray!, shares=[]
>>> > 2014-04-03 13:29:55.563 INFO cinder.openstack.common.service [-] Child
>>> > 30186
>>> > exited with status 1
>>> > Exception TypeError: "'NoneType' object is not callable" in <bound
>>> > method
>>> > GlusterfsDriver.__del__ of
>>> > <cinder.volume.drivers.glusterfs.GlusterfsDriver
>>> > object at 0x2777ed0>> ignored
>>> > [stack at devstack-vm tempest]$
>>> >
>>> > So the _mounted_shares is empty ([]) which isn't true since I have 2
>>> > glsuterfs shares mounted and when i print _mounted_shares in other
>>> > parts of
>>> > code, it does show me the right thing.. as below...
>>> >
>>> > From volume/drivers/glusterfs.py @ line 1062:
>>> >     LOG.debug(_('Available shares: %s') % self._mounted_shares)
>>> >
>>> > which dumps the debugprint  as below...
>>> >
>>> > 2014-04-03 13:29:45.414 DEBUG cinder.volume.drivers.glusterfs
>>> > [req-2cf69316-cc42-403a-96f1-90e8e77375aa None None] Available shares:
>>> > [u'devstack-vm.localdomain:/gvol1', u'devstack-vm.localdomain:/gvol1']
>>> > from
>>> > (pid=30185) _ensure_shares_mounted
>>> > /opt/stack/cinder/cinder/volume/drivers/glusterfs.py:1061
>>> >
>>> > This brings in few Qs ( I am usign devstack env) ...
>>> >
>>> > 1) Is __del__ the right way to do cleanup for a cinder driver ? I have
>>> > 2
>>> > gluster backends setup, hence 2 cinder-volume instances, but i see
>>> > __del__
>>> > being called once only (as per above debug prints)
>>> > 2) I tried atexit and registering a function to do the cleanup.
>>> > Ctrl-C'ing
>>> > c-vol (from screen ) gives the same issue.. shares is empty ([]), but
>>> > this
>>> > time i see that my atexit handler called twice (once for each backend)
>>> > 3) In general, whats the right way to do cleanup inside cinder volume
>>> > driver
>>> > when a service is going down or being restarted ?
>>> > 4) The solution should work in both devstack (ctrl-c to shutdown c-vol
>>> > service) and production (where we do service restart c-vol)
>>> >
>>> > Would appreciate a response
>>> >
>>> > thanx,
>>> > deepak
>>> >
>>> >
>>> > _______________________________________________
>>> > OpenStack-dev mailing list
>>> > OpenStack-dev at lists.openstack.org
>>> > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>>> >
>>>
>>>
>>>
>>> --
>>> Duncan Thomas
>>>
>>> _______________________________________________
>>> OpenStack-dev mailing list
>>> OpenStack-dev at lists.openstack.org
>>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
>>
>>
>
>
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-- 
Duncan Thomas