[ovs-dev] [PATCH RFC 2/2] release-process: LTS transition period and policy for unmaintained branches.

[Ilya Maximets]

On 9/1/20 2:00 PM, Simon Horman wrote:
> On Tue, Aug 25, 2020 at 02:24:11PM +0200, Ilya Maximets wrote:
>> While only 2 branches are formally maintained (LTS and latest release),
>> OVS team usually provides stable releases for other branches too, at
>> least for branches between LTS and latest.
>>
>> While LTS change happens, according to release-process.rst, we're
>> immediately dropping support for the old LTS and, according to
>> backporting-patches.rst could stop backporting bug fixes to branches
>> older than new LTS.  While this might be OK for an upstream project
>> (some upstream projects like QEMU doesn't support anything at all
>> except the last release) it doesn't sound like a user-friendly policy.
>>
>> Below addition to the release process might make the process a bit
>> smoother in terms that we will continue support of branches a little
>> bit longer even after changing current LTS, i.e. providing at least a
>> minimal transition period (1 release frame) for users of old LTS.
>> We will also not drop support for not so old branches even after the
>> transition period if committers will follow the "as far as it goes"
>> backporting policy.
>>
>> Still keeping the room for us to not backport disruptive changes or
>> changes that are hard to maintain or OVN related fixes anywhere but
>> LTS and the latest released branch.
>>
>> After 2 year period (4 releases) committers are still free to backport
>> fixes they think are needed on older branches, however we will likely
>> not provide actual releases on these branches, unless it's specially
>> requested and discussed.
>>
>> Effectively, this change means that we will support branch-2.5 until
>> 2.15 release, i.e. we will provide the last release, if any, on
>> branch-2.5 somewhere around Feb 2021. (I don't actually expect
>> much fixes there)  And, presumably, at the same time we will provide
>> last releases for branch 2.11 and below, if needed.
>>
>> Additionally, "4 releases" policy aligns with the DPDK LTS support
>> policy, i.e. we will be able to validate and release last OVS releases
>> with the last available DPDK LTS, e.g. OVS 2.11 last stable release
>> will likely be released with the 18.11 EOL release validated.
>>
>> Signed-off-by: Ilya Maximets <i.maximets at ovn.org>
> 
> This also sounds reasonable to me but I don't feel that I am in a position
> to sign off on it.
> 
> Reviewed-by: Simon Horman <simon.horman at netronome.com>
> 
> Do you, as a follow-up, plan to open a discussion on formalising the
> LTS selection process?

It's probably better do that with this patch.  Please, take a look at my
reply to Flavio.

Best regards, Ilya Maximets.