Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-09-12 Thread Russell Bryant
On 09/11/2014 05:01 PM, Jay Pipes wrote: On 09/11/2014 04:51 PM, Matt Riedemann wrote: On 9/10/2014 6:00 PM, Russell Bryant wrote: On 09/10/2014 06:46 PM, Joe Cropper wrote: Hmm, not sure I follow the concern, Russell. How is that any different from putting a VM into the group when it’s

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-09-11 Thread Sylvain Bauza
Le 11/09/2014 01:10, Joe Cropper a écrit : Agreed - I’ll draft up a formal proposal in the next week or two and we can focus the discussion there. Thanks for the feedback - this provides a good framework for implementation considerations. Count me on it, I'm interested in discussing the

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-09-11 Thread Joe Cropper
Great to hear. I started a blueprint for this [1]. More detail can be added once the kilo nova-specs directory is created… for now, I’ve tried to put some fairly detailed notes on the blueprint’s description. [1] https://blueprints.launchpad.net/nova/+spec/dynamic-server-groups - Joe On Sep

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-09-11 Thread Matt Riedemann
On 9/10/2014 6:00 PM, Russell Bryant wrote: On 09/10/2014 06:46 PM, Joe Cropper wrote: Hmm, not sure I follow the concern, Russell. How is that any different from putting a VM into the group when it’s booted as is done today? This simply defers the ‘group insertion time’ to some time after

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-09-11 Thread Jay Pipes
On 09/11/2014 04:51 PM, Matt Riedemann wrote: On 9/10/2014 6:00 PM, Russell Bryant wrote: On 09/10/2014 06:46 PM, Joe Cropper wrote: Hmm, not sure I follow the concern, Russell. How is that any different from putting a VM into the group when it’s booted as is done today? This simply defers

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-09-11 Thread Chris Friesen
On 09/11/2014 03:01 PM, Jay Pipes wrote: On 09/11/2014 04:51 PM, Matt Riedemann wrote: On 9/10/2014 6:00 PM, Russell Bryant wrote: On 09/10/2014 06:46 PM, Joe Cropper wrote: Hmm, not sure I follow the concern, Russell. How is that any different from putting a VM into the group when it’s

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-09-11 Thread Joe Cropper
I would be a little wary about the DB level locking for stuff like that — it’s certainly doable, but also comes at the expense of things behaving ever-so-slightly different from DBMS to DBMS. Perhaps there are multiple “logical efforts” here—i.e., adding some APIs and cleaning up existing

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-09-10 Thread Joe Cropper
I agree, Chris. I think a number of folks put in a lot of really great work into the existing server groups and there has been a lot of interest on their usage, especially given that the scheduler already has some constructs in place to piggyback on them. I would like to craft up a blueprint

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-09-10 Thread Russell Bryant
On Sep 10, 2014, at 2:03 PM, Joe Cropper cropper@gmail.com wrote: I agree, Chris. I think a number of folks put in a lot of really great work into the existing server groups and there has been a lot of interest on their usage, especially given that the scheduler already has some

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-09-10 Thread Joe Cropper
Hmm, not sure I follow the concern, Russell. How is that any different from putting a VM into the group when it’s booted as is done today? This simply defers the ‘group insertion time’ to some time after initial the VM’s been spawned, so I’m not sure this creates anymore race conditions than

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-09-10 Thread Chris Friesen
On 09/10/2014 04:16 PM, Russell Bryant wrote: On Sep 10, 2014, at 2:03 PM, Joe Cropper cropper@gmail.com wrote: I would like to craft up a blueprint proposal for Kilo to add two simple extensions to the existing server group APIs that I believe will make them infinitely more usable in

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-09-10 Thread Russell Bryant
On 09/10/2014 06:46 PM, Joe Cropper wrote: Hmm, not sure I follow the concern, Russell. How is that any different from putting a VM into the group when it’s booted as is done today? This simply defers the ‘group insertion time’ to some time after initial the VM’s been spawned, so I’m not

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-09-10 Thread Joe Cropper
+1, Chris. I think the key thing here is that such race conditions can already happen if timed just right, unless there’s been some additional checks put in place in the compute API layer since I last scanned the code. We could even look at some x-process locking mechanisms as well if we

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-09-10 Thread Joe Cropper
Agreed - I’ll draft up a formal proposal in the next week or two and we can focus the discussion there. Thanks for the feedback - this provides a good framework for implementation considerations. - Joe On Sep 10, 2014, at 6:00 PM, Russell Bryant rbry...@redhat.com wrote: On 09/10/2014 06:46

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-08-26 Thread Chris Friesen
On 08/25/2014 11:25 AM, Joe Cropper wrote: I was thinking something simple such as only allowing the add operation to succeed IFF no policies are found to be in violation... and then nova wouldn't need to get into all the complexities you mention? Personally I would be in favour of

[openstack-dev] [nova] Server Groups - remove VM from group?

2014-08-25 Thread Joe Cropper
Hello, Is our long-term vision to allow a VMs to be dynamically added/removed from a group? That is, unless I'm overlooking something, it appears that you can only add a VM to a server group at VM boot time and effectively remove it by deleting the VM? Just curious if this was a design point,

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-08-25 Thread Jay Pipes
On 08/25/2014 11:10 AM, Joe Cropper wrote: Hello, Is our long-term vision to allow a VMs to be dynamically added/removed from a group? That is, unless I'm overlooking something, it appears that you can only add a VM to a server group at VM boot time and effectively remove it by deleting the

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-08-25 Thread Joe Cropper
Thanks Jay. Those are the same types of questions I was pondering as well when debating how someone might use this. I think what we have is fine for a first pass, but that's what I was poking at... whether some of the abilities to add/remove members dynamically could exist (e.g., I no longer

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-08-25 Thread Jay Pipes
On 08/25/2014 11:31 AM, Joe Cropper wrote: Thanks Jay. Those are the same types of questions I was pondering as well when debating how someone might use this. I think what we have is fine for a first pass, but that's what I was poking at... whether some of the abilities to add/remove members

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-08-25 Thread Joe Cropper
That was indeed a rather long (and insightful) thread on the topic. It sounds like there are still some healthy discussions worth having on the subject -- either exploring your [potentially superseding] proposal, or minimally rounding out the existing server group API to support add existing VM

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-08-25 Thread Russell Bryant
On 08/25/2014 12:56 PM, Joe Cropper wrote: That was indeed a rather long (and insightful) thread on the topic. It sounds like there are still some healthy discussions worth having on the subject -- either exploring your [potentially superseding] proposal, or minimally rounding out the existing

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-08-25 Thread Joe Cropper
I was thinking something simple such as only allowing the add operation to succeed IFF no policies are found to be in violation... and then nova wouldn't need to get into all the complexities you mention? And remove would be fairly straightforward as well since no constraints would need to be

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-08-25 Thread Russell Bryant
On 08/25/2014 01:25 PM, Joe Cropper wrote: I was thinking something simple such as only allowing the add operation to succeed IFF no policies are found to be in violation... and then nova wouldn't need to get into all the complexities you mention? Even something like this is a lot more

Re: [openstack-dev] [nova] Server Groups - remove VM from group?

2014-08-25 Thread Joe Cropper
Even something like this is a lot more complicated than it sounds due to the fact that several operations can be happening in parallel. That's fair, but I was thinking that the 'add existing' VM is fairly close in behavior to 'add new' VM to the group, less of course any parallel operations