[Engine-devel] Introducing virt / gluster flags at cluster level

[Eli Mesika]

----- Original Message -----
> From: "Moti Asayag" <masayag at redhat.com>
> To: engine-devel at ovirt.org
> Sent: Sunday, March 4, 2012 12:20:43 PM
> Subject: Re: [Engine-devel] Introducing virt / gluster flags at cluster level
> 
> On 03/01/2012 12:54 PM, Shireesh Anjal wrote:
> > Hi,
> > 
> > In order to identify whether a cluster exposes Gluster /
> > Virtualization
> > capabilities, we plan to introduce two boolean columns -
> > virt_service
> > and gluster_service in the vds_groups table. As per immediate
> > plans, it
> > is intended to support only one service per cluster, meaning only
> > one of
> > these two values can be true.
> 
> Couldn't there be additional future services in the future ? In that
> case perhaps worth considering enum for services, to be stored in a
> single service column, its values are: virt, gluster,...) instead of
> extending the vds_group table consistently when introducing new
> services
> (under the assumption no mix of services is allowed).
> 
> > 
> > We plan to make following changes as part of the patch:
> > 
> > 1) Introduce an upgrade script for adding following columns to the
> > table
> > "vds_groups"
> >     - virt_service - boolean - NOT_NULL - default value true
> >     - gluster_service - boolean - NOT_NULL - default value false
> > 
> > => What is the naming convention for naming the upgrade script? Is
> > it
> > <major-version>_<minor-version>_<running-sequence-with-step-10>_script_description.sql
> > ? By that logic, the name of our script will be something like
> > 03_01_0560_add_service_columns_to_vds_groups.sql
> 
> Correct. Make sure to verify script sequence uniqueness (under
> ovirt-engine/backend/manager/dbscripts/upgrade) before pushing, since
> there is no enforcement for that.
> 
> > 
> > 2) Modify vds_groups_sp.sql to introduce these arguments /

Keep in mind that all sp parameters should start with "v_"

> > variables in
> > save and update methods

Aren't those columns need to be added to relevant views in create_views.sql ???

> > 
> > 3) Modify the DAO interface and implementation to introduce these
> > arguments / variables in the save/update methods and
> > VdsGroupRawMapper.
> > 
> > 4) Modify the DAO JUnit test class to take care of these new
> > fields, if
> > required.
> 
> As part of DAO unit-test you should add the new columns and possible
> data to
> ovirt-engine/backend/manager/modules/dal/src/test/resources/fixtures.xml
> 
> > 
> > 5) Modify class VDSGroup to introduce the two new boolean variables
> > virtService and glusterService and modify the methods equals and
> > hashCode to use these.
> > 
> > => One question here. Most of the attributes of class VDSGroup have
> > annotations like @XmlElement and @Column. I think these are related
> > to
> > jaxb and JPA. Are these annotations really required? If yes, how
> > are
> > they useful?
> > 
> 
> @XmlElement annotations could be deleted from that file as a prior
> patch
> to the patch-set.
> 
> JPA annotations could be ignored as not fully supported nor
> maintained.
> 
> > 6) REST API : Default populate these variables (virtService = true,
> > glusterService = false) before invoking the BLL command
> > (AddVdsGroupCommand / UpdateVdsGroupCommand). This makes sure that
> > the
> > existing API won't break. No change in api.xsd for now.
> > 
> > 7) webadmin create cluster code: Default populate the new
> > variables,
> > same as above. No change in UI screen for now.
> > 
> > => Alternatively, the variable declaration on VDSGroup itself can
> > initialize these variables with default values, so that changes to
> > UI /
> > REST API code (points 6 and 7) may not be required immediately.
> > What do
> > you suggest?
> > 
> > Inputs / comments / suggestions welcome.
> > 
> 
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