Re: The meaning, or not, of “LTS”

Remi Forax forax at
Sun May 16 14:54:43 UTC 2021

----- Mail original -----
> De: "Anthony Vanelverdinghe" <dev at>
> À: "cay" <cay at>
> Cc: "jdk-dev" <jdk-dev at>
> Envoyé: Dimanche 16 Mai 2021 15:41:54
> Objet: Re: The meaning, or not, of “LTS”

> Preview features are specified in the Java SE Platform JSRs, hence tested in
> their accompanying TCKs, and thus must remain unaltered. On the other hand,
> incubator modules are not, so I believe vendors are allowed to ship upgraded
> versions (though I don't readily see the value in doing so: developers using
> incubator modules are likely to upgrade to subsequent JDKs anyway), or not ship
> them at all.

Given that for incubator modules, each new versions is incompatible with the previous one (it's not mandatory but it's what's appear in practice),
shipping a new version of an incubator module in a LTS updates seems to have no value, you need to do more work to release something which is not compatible with the previous update.

> Kind regards,
> Anthony


> On Sunday, May 16, 2021 14:37 CEST, Cay Horstmann <cay.horstmann at>
> wrote:
>> What happens with experimental, preview, and incubator features that are
>> introduced in an LTS and subsequently modified? Are providers of an LTS
>> obligated to keep the feature in its unmodified form, or may they drop
>> it or replace it with a later version? I am just wondering about the
>> effort of keeping an obsolete feature version alive for many years.
>> Thanks,
>> Cay
>> On 14/05/2021 00:37, mark.reinhold at wrote:
>> > I’ve heard a few contributors report that they’ve received advice along
>> > the lines of, “since JDK 17 is an LTS we should focus on stability, and
>> > avoid doing major enhancements.”
>> >
>> > This suggests that the stability of non-LTS releases is not important,
>> > but nothing is further from the truth.  We should focus on stability
>> > in every JDK release, since every JDK release is meant to be ready for
>> > production use.  That a release is designated an LTS release is no
>> > reason to hold back on innovation.
>> >
>> > If you have an enhancement that will preserve stability and is ready to
>> > integrate then, by all means, please proceed with the usual high level
>> > of care and consideration.  Whether the target release is an LTS or not
>> > is, in almost all ways, completely irrelevant.
>> >
>> > - Mark
>> >
>> --
> > Cay S. Horstmann | | mailto:cay at

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