[Rdo-list] OpenStack upgrade Icehouse Centos 6 best practice

[Ihar Hrachyshka]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

On 08/18/2015 06:21 AM, Chris wrote:
> Hello,
> 
> Here some more insights and questions:
> 
> We have in total 4 separate clouds who need the upgrade with each
> more than 100 compute nodes. We just use the basic services like
> nova, keystone, neutron, glance and horizon. No Cinder, heat, trove
> etc. Our network setup is flat provider network, which means we
> don't use the neutron router. All in all the from the openstack
> service perspective a minimal setup.
> 
> One of our cloud is set up as HA with two management nodes
> (keystone, nova, horizon, glance) behind a haproxy. It's not a big
> deal to have the same setup implemented in all clouds if it's
> helpful for the upgrade
> 
> We don't think about upgrading from Centos 6 to 7. Instead build
> new Centos 7 compute nodes and move the VMs with live migration (is
> it a good idea?)
> 
> The database schemes changes between the openstack versions, what
> does it affect? Let's say we set up a second management node wit
> Centos 7 and the openstack Juno/Kilo services will it work against
> the Centos 6/Icehouse compute nodes and the Icehouse DB schema?

It definitely won't work with old schema for most services (nova can
be a single exception, with their support for live data migration).

There is currently no way to run a mixed version setup of management
services. The only mix that is expected to work now is a setup where
management services (those services that have access to database) have
higher versions than agents/compute nodes do (it's expected that RPC
used between management nodes and compute/networking nodes is backward
compatible for at least one major release).

Note that skipping a major version in staged upgrade is not guaranteed
to work (meaning, you should avoid running Icehouse computes against
Kilo controller).

Ihar
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2

iQEcBAEBCAAGBQJV0v6JAAoJEC5aWaUY1u57nicH/15oldYrgouH4qENDdQTRyXK
orBxLX9XYJHGMAXFgVV3NBbuuUo6Dy89FPZWlx3sFoPZC+GOpYPXCAWEnFgjNjnB
iSMWLe7TGDCKqiswjoLhK1is3Pc+V1XUUGZTFrP5XAsVkcnEwjGW9e1T7ohK3O3g
OCALYyR+fqFP42gQQb47TY1QfSDNX7bzB443uSL6EKIS2yORo0bssGQozpO9hglR
P76f2DscYlYcgXtf6G0d8q3sz5zfernzJjirI+y/tXqOa28wFCIlvCjg+eHiS0rx
csguINcN2+wm8quhSis3p1cmuxa4Z7TCgNoOkR99HL2Za5A1ph0FAh6dXFZHyE0=
=amtY
-----END PGP SIGNATURE-----