+1 to this. Evan, can you report a bug (if one hasn't been reported yet) and propose the fix? Or else I can find someone else to propose it.
Vish On Aug 23, 2012, at 1:38 PM, Evan Callicoat <diop...@gmail.com> wrote: > Hello all! > > I'm the original author of the hairpin patch, and things have changed a > little bit in Essex and Folsom from the original Diablo target. I believe I > can shed some light on what should be done here to solve the issue in either > case. > > --- > For Essex (stable/essex), in nova/virt/libvirt/connection.py: > --- > > Currently _enable_hairpin() is only being called from spawn(). However, > spawn() is not the only place that vifs (veth#) get added to a bridge (which > is when we need to enable hairpin_mode on them). The more relevant function > is _create_new_domain(), which is called from spawn() and other places. > Without changing the information that gets passed to _create_new_domain() > (which is just 'xml' from to_xml()), we can easily rewrite the first 2 lines > in _enable_hairpin(), as follows: > > def _enable_hairpin(self, xml): > interfaces = self.get_interfaces(xml['name']) > > Then, we can move the self._enable_hairpin(instance) call from spawn() up > into _create_new_domain(), and pass it xml as follows: > > [...] > self._enable_hairpin(xml) > return domain > > This will run the hairpin code every time a domain gets created, which is > also when the domain's vif(s) gets inserted into the bridge with the default > of hairpin_mode=0. > > --- > For Folsom (trunk), in nova/virt/libvirt/driver.py: > --- > > There've been a lot more changes made here, but the same strategy as above > should work. Here, _create_new_domain() has been split into _create_domain() > and _create_domain_and_network(), and _enable_hairpin() was moved from > spawn() to _create_domain_and_network(), which seems like it'd be the right > thing to do, but doesn't quite cover all of the cases of vif reinsertion, > since _create_domain() is the only function which actually creates the domain > (_create_domain_and_network() just calls it after doing some pre-work). The > solution here is likewise fairly simple; make the same 2 changes to > _enable_hairpin(): > > def _enable_hairpin(self, xml): > interfaces = self.get_interfaces(xml['name']) > > And move it from _create_domain_and_network() to _create_domain(), like > before: > > [...] > self._enable_hairpin(xml) > return domain > > I haven't yet tested this on my Essex clusters and I don't have a Folsom > cluster handy at present, but the change is simple and makes sense. Looking > at to_xml() and _prepare_xml_info(), it appears that the 'xml' variable > _create_[new_]domain() gets is just a python dictionary, and xml['name'] = > instance['name'], exactly what _enable_hairpin() was using the 'instance' > variable for previously. > > Let me know if this works, or doesn't work, or doesn't make sense, or if you > need an address to send gifts, etc. Hope it's solved! > > -Evan > > On Thu, Aug 23, 2012 at 11:20 AM, Sam Su <susltd...@gmail.com> wrote: > Hi Oleg, > > Thank you for your investigation. Good lucky! > > Can you let me know if find how to fix the bug? > > Thanks, > Sam > > On Wed, Aug 22, 2012 at 12:50 PM, Oleg Gelbukh <ogelb...@mirantis.com> wrote: > Hello, > > Is it possible that, during snapshotting, libvirt just tears down virtual > interface at some point, and then re-creates it, with hairpin_mode disabled > again? > This bugfix [https://bugs.launchpad.net/nova/+bug/933640] implies that fix > works on spawn of instance. This means that upon resume after snapshot, > hairpin is not restored. May be if we insert the _enable_hairpin() call in > snapshot procedure, it helps. > We're currently investigating this issue in one of our environments, hope to > come up with answer by tomorrow. > > -- > Best regards, > Oleg > > On Wed, Aug 22, 2012 at 11:29 PM, Sam Su <susltd...@gmail.com> wrote: > My friend has found a way to enable ping itself, when this problem happened. > But not found why this happen. > sudo echo "1" > > /sys/class/net/br1000/brif/<virtual-interface-name>/hairpin_mode > > I file a ticket to report this problem: > https://bugs.launchpad.net/nova/+bug/1040255 > > hopefully someone can find why this happen and solve it. > > Thanks, > Sam > > > On Fri, Jul 20, 2012 at 3:50 PM, Gabriel Hurley <gabriel.hur...@nebula.com> > wrote: > I ran into some similar issues with the _enable_hairpin() call. The call is > allowed to fail silently and (in my case) was failing. I couldn’t for the > life of me figure out why, though, and since I’m really not a networking > person I didn’t trace it along too far. > > > > Just thought I’d share my similar pain. > > > > - Gabriel > > > > From: openstack-bounces+gabriel.hurley=nebula....@lists.launchpad.net > [mailto:openstack-bounces+gabriel.hurley=nebula....@lists.launchpad.net] On > Behalf Of Sam Su > Sent: Thursday, July 19, 2012 11:50 AM > To: Brian Haley > Cc: openstack > Subject: Re: [Openstack] VM can't ping self floating IP after a snapshot is > taken > > > > Thank you for your support. > > > > I checked the file nova/virt/libvirt/connection.py, the sentence > self._enable_hairpin(instance) is already added to the function > _hard_reboot(). > > It looks like there are some difference between taking snapshot and reboot > instance. I tried to figure out how to fix this bug but failed. > > > > It will be much appreciated if anyone can give some hints. > > > > Thanks, > > Sam > > > > On Thu, Jul 19, 2012 at 8:37 AM, Brian Haley <brian.ha...@hp.com> wrote: > > On 07/17/2012 05:56 PM, Sam Su wrote: > > Hi, > > > > Just This always happens in Essex release. After I take a snapshot of my VM > > ( I > > tried Ubuntu 12.04 or CentOS 5.8), VM can't ping its self floating IP; > > before I > > take a snapshot though, VM can ping its self floating IP. > > > > This looks closely related to https://bugs.launchpad.net/nova/+bug/933640, > > but > > still a little different. In 933640, it sounds like VM can't ping its self > > floating IP regardless whether we take a snapshot or not. > > > > Any suggestion to make an easy fix? And what is the root cause of the > > problem? > > It might be because there's a missing _enable_hairpin() call in the reboot() > function. Try something like this... > > nova/virt/libvirt/connection.py, _hard_reboot(): > > self._create_new_domain(xml) > + self._enable_hairpin(instance) > self.firewall_driver.apply_instance_filter(instance, > network_info) > > At least that's what I remember doing myself recently when testing after a > reboot, don't know about snapshot. > > Folsom has changed enough that something different would need to be done > there. > > -Brian > > > > > > _______________________________________________ > Mailing list: https://launchpad.net/~openstack > Post to : openstack@lists.launchpad.net > Unsubscribe : https://launchpad.net/~openstack > More help : https://help.launchpad.net/ListHelp > > > > > _______________________________________________ > Mailing list: https://launchpad.net/~openstack > Post to : openstack@lists.launchpad.net > Unsubscribe : https://launchpad.net/~openstack > More help : https://help.launchpad.net/ListHelp > > > _______________________________________________ > Mailing list: https://launchpad.net/~openstack > Post to : openstack@lists.launchpad.net > Unsubscribe : https://launchpad.net/~openstack > More help : https://help.launchpad.net/ListHelp
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