[openstack-dev] [TripleO][Tuskar] Terminology

Robert Collins robertc at robertcollins.net
Thu Dec 12 00:21:42 UTC 2013


On 12 December 2013 08:15, Tzu-Mainn Chen <tzumainn at redhat.com> wrote:
> Hi,
>
> I'm trying to clarify the terminology being used for Tuskar, which may be helpful so that we're sure
> that we're all talking about the same thing :)  I'm copying responses from the requirements thread
> and combining them with current requirements to try and create a unified view.  Hopefully, we can come
> to a reasonably rapid consensus on any desired changes; once that's done, the requirements can be
> updated.
>
> * NODE a physical general purpose machine capable of running in many roles. Some nodes may have hardware layout that is particularly
>        useful for a given role.
>
>      * REGISTRATION - the act of creating a node in Ironic
>
>      * ROLE - a specific workload we want to map onto one or more nodes. Examples include 'undercloud control plane', 'overcloud control
>        plane', 'overcloud storage', 'overcloud compute' etc.
>
>          * MANAGEMENT NODE - a node that has been mapped with an undercloud role

Pedantically, this is 'A node with an instance of a management role
running on it'. I think calling it 'management node' is too sticky.
What if we cold migrate it to another machine when a disk fails and we
want to avoid dataloss if another disk were to fail?

Management instance?

>          * SERVICE NODE - a node that has been mapped with an overcloud role

Again, the binding to node is too sticky IMNSHO.

Service instance? Cloud instance?

>             * COMPUTE NODE - a service node that has been mapped to an overcloud compute role
>             * CONTROLLER NODE - a service node that has been mapped to an overcloud controller role
>             * OBJECT STORAGE NODE - a service node that has been mapped to an overcloud object storage role
>             * BLOCK STORAGE NODE - a service node that has been mapped to an overcloud block storage role

s/Node/instance/ ?

>          * UNDEPLOYED NODE - a node that has not been mapped with a role
>               * another option - UNALLOCATED NODE - a node that has not been allocated through nova scheduler (?)
>                                    - (after reading lifeless's explanation, I agree that "allocation" may be a
>                                       misleading term under TripleO, so I personally vote for UNDEPLOYED)

I like 'available' because it is a direct statement that doesn't
depend on how things are utilised - mapping or allocation or
deployment or whatever. It is available for us to do something with
it.
'Available nodes'.


>      * INSTANCE - A role deployed on a node - this is where work actually happens.
>
> * DEPLOYMENT
>
>      * SIZE THE ROLES - the act of deciding how many nodes will need to be assigned to each role
>            * another option - DISTRIBUTE NODES (?)
>                                  - (I think the former is more accurate, but perhaps there's a better way to say it?)

Perhaps 'Size the cloud' ? "How big do you want your cloud to be?"

>      * SCHEDULING - the process of deciding which role is deployed on which node

This possible should be a sub step of deployment.

>      * SERVICE CLASS - a further categorization within a service role for a particular deployment.

See the other thread where I suggested perhaps bringing the image +
config aspects all the way up - I think that renames 'service class'
to 'Role configuration'. KVM Compute is a role configuration. KVM
compute(GPU) might be another.

>           * NODE PROFILE - a set of requirements that specify what attributes a node must have in order to be mapped to
>                            a service class

Today the implementation at the plumbing layer can only do 'flavour',
though Heat is open to letting us to 'find an instance from any of X
flavors' in future. Lets not be -too- generic:
'Flavor': The Nova description of a particular machine configuration,
and choosing one is part of setting up the 'role configuration'.

Thanks for drafting this!

-Rob


-- 
Robert Collins <rbtcollins at hp.com>
Distinguished Technologist
HP Converged Cloud



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