On 03/18/2013 01:30 PM, Omer Frenkel wrote:
----- Original Message -----
From: "Shireesh Anjal" <sanjal@redhat.com> To: engine-devel@ovirt.org Sent: Monday, March 18, 2013 8:28:14 AM Subject: [Engine-devel] FeatureSupported and compatibility versions
Hi all,
The current mechanism in oVirt to check whether a feature is supported in a particular compatibility version is to use the FeatureSupported class. e.g.
FeatureSupported.networkLinking(getVm().getVdsGroupCompatibilityVersion())
Checks whether the "network linking" feature is supported for the the VM's cluster compatibility version. This internally checks whether the value of the corresponding config (NetworkLinkingSupported) for the given compatibility version is true/false.
I'm not sure if this is a good idea, since a feature is typically supported "from" a particular version. E.g. Gluster support was introduced in 3.1, and it continues to be available in all subsequent versions. So I see no point in adding configuration for every version indicating whether the feature is supported in that version or not. I suggest to use either of the following options:
1) Instead of using a boolean config for each version, use a single string config that indicates the "supported from" version e.g. GlusterSupportedFrom = 3.1. There could be rare cases where a feature, for some reason, is removed in some release. In such cases, we could use one additional config for the "supported to" version.
2) Continue with the boolean approach, but do not have entries for every version; rather make use of the "default value" for majority of cases, and add the explicit version mapping for the minority e.g. GlusterSupported = true by default, and false in case of 3.0 (only one config required for 3.0)
i like this approach better, if one add new feature for 3.3 he should add it as 'true' in the config to be used as default, and explicitly add it as false for other unsupported versions.
For the record, this was the approach that was finally approved on the patch and merged (http://gerrit.ovirt.org/12970) So I think now onwards, everyone can start using this approach for new features being added.
if we do go this way, we need to make sure it works because i vaguely remember we had a bug in configuration, making us explicitly specify value for all versions.
I wrote a test case on DBConfigUtils that verifies that it does indeed work fine (http://gerrit.ovirt.org/13787), which has also been approved and merged.
Thoughts?
Regards, Shireesh _______________________________________________ Engine-devel mailing list Engine-devel@ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel