Open Stack

+1

Some people think Cloud means 'magic' and failed physical instances should recover to the previous state. Most of the times this is not possible at app level, and I wonder if desirable.

Still, Nova lacks of features like 'HA' instances and instances running on remote block storage (like EBS backed instances in AWS).I think this is basic for self-healing features needed for real DR.


Enviado desde mi iPad

El 02/04/2011, a las 22:46, Jesse Andrews <anotherjesse at gmail.com> escribió:

> What to do when an instance dies is application specific.
> 
> Some applications may not care, autoscaling back to the proper size by themselves. Other applications may need the resources to be returned in the most recent state.
> 
> Currently openstack requires the user to handle recovery.
> 
> I expect there will be an option to mark a virtual machine as "HA" which would attempt to relaunch on crashes. How exactly to implement it will depend on the cloud requirements. If the instances are backed to a SAN or distributed filesystem (like ceph) the VM can be relaunched with all state that has been flushed to disk. On a cloud with local disk only, the scheduled snapshotting could allow the vm to a recent state.
> 
> Or HA could mean relaunch the image (ala autoscale)
> 
> What use case are you thinking about?
> 
> Jesse
> 
> On Apr 2, 2011 1:33 PM, "Marek Denis" <marek at octogan.net> wrote:
> > Hello,
> > 
> > I have been trying to find out some info about features OpenStack 
> > provide and still cannot figure out whether 'cloud features' are 
> > available by default. By 'cloud features' I mean proper handling 
> > situations where we have many instances running on many different 
> > hardware servers. Suddently one server (physically) goes down, something 
> > bad happened. How will the OpenStack as a cloud behave by default? Will 
> > it run all the lost instances on other hardware servers or this should 
> > be specifically configured or programmed? How about data replication? 
> > Users shouldn't notice anything, as all the instances are ran in the 
> > cloud. Is it available by default? I couldn't find any docs that would 
> > explain these topics in a detailed way. Thanks for your explanation.
> > -- 
> > regards
> > 
> > M
> > 
> > 
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