Re: [Engine-devel] FeatureSupported and compatibility versions

From: "Shireesh Anjal" <sanjal(a)redhat.com&gt; To: engine-devel(a)ovirt.org Cc: "Omer Frenkel" <ofrenkel(a)redhat.com&gt; Sent: Thursday, May 2, 2013 1:03:23 PM Subject: Re: [Engine-devel] FeatureSupported and compatibility versions On 03/18/2013 01:30 PM, Omer Frenkel wrote: > > ----- Original Message ----- >> From: "Shireesh Anjal" <sanjal(a)redhat.com&gt; >> To: engine-devel(a)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(a)ovirt.org >> http://lists.ovirt.org/mailman/listinfo/engine-devel >>