[CentOS-virt] Xen Version update policy

Thu Dec 12 14:38:36 UTC 2019
George Dunlap <dunlapg at umich.edu>

On Thu, Nov 28, 2019 at 6:12 PM George Dunlap <dunlapg at umich.edu> wrote:
> Hey all,
> This mail has been a long time in coming, but with the upcoming
> expiration of security support for Xen 4.8, it's time to start thinking
> about what our update policy will be for the Xen packages in general.
> Citrix is committed to officially supporting one Xen version at a time
> through the CentOS Virt SIG.  (Others in the community are welcome to
> support others.)  But we'd like input as to which version the community
> would like to be supported at any one time.
> Please express your opinion on each option by replying as follows:
> -2: This is a bad idea, and I would argue against this
> -1: I'm not happy with this, but I wouldn't argue against this.
> 0: No opinion.
> 1: I'm happy with this, but I wouldn't argue for it.
> 2: This is a great idea, and I'd argue for it.
> There are several possible options:
> 1. Always support the newest option.  This means we get all the newest
> features from Xen in the Virt SIG by default; but also means we get all
> the newest bugs.
> 1a. Always support the newest option once it has at least one point
> release.  This balances the newness with a bit of extra testing.
> 1b. Always support the second-to-newest version (e.g., when 4.13 comes
> out, switch to 4.12.x)
> 2. Always support the oldest security-supported version.  This means we
> get the most stable version of Xen; but it does mean it is several years
> behind as far as features go.  It also means that further bugfixes do
> not happen automatically, and further bugs found will need to be
> 3. Always support the oldest fully-supported version.  Reasonably
> stable, reasonably old, still gets bugfixes.
> 4. Support a version until it's out of security support, then jump to
> the newest version.  This minimizes the number of upgrades required
> (although may make each upgrade more painful).
> 4a.  Support a version until it's out of full support, then jump to the
> newest version.

So the voting results look sort of like this:

1: 0, -2
1a: 1, -1
1b: 1, 2
 -> 1 or 1a or 1b: +2

2:  0, -2
3:  0, 2
4:  0, -1, -1
4a: 0, -2, -1

Meaning 1b, "Always support the second-to-newest version" seems to be
the best fit.

Since a 4.13 release is imminent, I think we'll probably switch to
4.12 as the default / main supported release once that's out, and then
update every release.