[Engine-devel] [engine-devel] instance type as top-level entity

[Omer Frenkel]

----- Original Message -----
> From: "Tomas Jelinek" <tjelinek at redhat.com>
> To: "engine-devel" <engine-devel at ovirt.org>
> Cc: "Omer Frenkel" <ofrenkel at redhat.com>
> Sent: Wednesday, December 4, 2013 2:14:06 PM
> Subject: [engine-devel] instance type as top-level entity
> 
> Hey all,
> 
> I have started to work on the instance types[1] again and hit an issue. Since
> the instance types are supposed to be top-level entities
> (e.g. without the connection to DC/Cluster) but they are modeled as templates
> it is not possible to store them to DB since the DB constraints violation on
> vm_static table
> (e.g. the vds_group_id has to be unique and point to an existing vds_group).
> 
> So, I see 4 options:
> 
> 1: drop the constraints on the vm_static.vds_group_id (the
> vds_groups_vm_static constraint)
>    (most simple approach but would open the door to some issues which are now
>    guard on the DB level)
> 
> 2: do the same magic [well, hacks :) ] as with the "blank" template which is
> in the same situation
>    (not exactly a nice solution to have the instance types wired to one
>    specific cluster just to satisfy the constraint but return them all the
>    time)
> 
> 3: do not store this data in vm_static but create some new table called e.g.
> instance_type which would contain all of the fields from vm_static which are
> needed by it
>    (actually the best approach AFAIK but to do it correctly it would require
>    some more refactoring to do some hierarchy of tables and not copy the
>    fields from table to table)
> 
> 4: make the instance types not top-level (e.g. bound to specific DC/Cluster)
>    (would bring some issues for example with the default instance types which
>    should be present for all the DC/Clusters)
> 
> Thoughts?
> 
> Thank you,
> Tomas
> 
> [1]: http://www.ovirt.org/Features/Instance_Types
> 

according to the wiki (and discussions we had) instance type is bounded to a cluster (even if only as a changeable default)
so i dont think there is an issue..