Open Stack

On Mon, 2014-04-14 at 07:45 -0700, Clint Byrum wrote:
> Excerpts from Russell Bryant's message of 2014-04-14 07:18:49 -0700:
> > On 04/14/2014 09:45 AM, Jiangying (Jenny) wrote:
> > > Pacemaker provides the high availability for openstack infrastructure.
> > > 
> > > We'd like to deliver the vm-level HA to improve the business continuity
> > > with openstack.
> > > 
> > > Besides host failure, Our HA mechanism can detect and report host
> > > isolation, network partition as well as ha agent down.
> > > 
> > > Ha agent is placed on every node of the system. The master agent is
> > > elected automatically on system startup and others will be regarded as
> > > the slave.
> > > 
> > > For the host states detection, the ha agents communicates through the
> > > storage subsystem as well as over the management network. Multiple
> > > communication paths enable better assessment of the health of the host.
> > > On host failure, the master agent selects the candidate hosts and calls
> > > the slave ha agents. The slave ha agents talk to the nova compute to
> > > restart the virtual machine. The master agent reacts to ha agent down by
> > > reporting to the administrator. During the network partition or host
> > > isolation event, the HA mechanism will not interrupt the virtual
> > > machines and just keep them running.
> > > 
> > > For the virtual machine detection, the ha agents relies on nova compute
> > > for the information about virtual machines.
> > > 
> > > Please let me know your comments on this.
> > 
> > In the past we've pushed back on this pretty heavily because it isn't
> > really relevant for new cloud-style architectures.  The push on this
> > functionality from a lot of users is pretty insistent so I expect it to
> > be added at some point in some way, it's just a question of the most
> > appropriate way.
> > 
> > What I would like to see is to *not* have this be in Nova.  I'd like to
> > make sure Nova exposes all necessary information and actions through the
> > API to make implementing this possible.  However, I think the
> > functionality generally belongs as something outside of Nova.
> > 
> > If it's something that lives outside of Nova, then we should discuss it
> > in terms of public APIs (whether that's Nova's API, or a combination of
> > Nova and Ceilometer, perhaps).
> > 
> 
> For the most part we've been trying to encourage projects that want to
> control VMs to add such functionality to the Orchestration program, aka
> "Heat".

Yes, exactly.

-jay