OpenJdk 11 vs OpenJdk 13 Adoption

[John Patrick]

Hi Steven,

- JDK 1.8, 11 and (17 TBC) are LTS versions so supported longest.
- JDK 9, 10, 12, 13, 14, 15, 16 are non-LTS versions and are only
supported until the next release.
- JDK 13 went out of support when JDK 14 was released. So I wouldn't
pick JDK 13 to upgrade too.
- JDK 14 is the current latest version in support.

Assuming the new 6 months release cycles keep happening and it is not
changed then the following will probably be also true;
- JDK 14 will go out of support when JDK 15 is released in ~20 days
(Mid Sept 2020).
- JDK 15 will go out of support when JDK 16 is released in ~6 months
(March 2021).
- JDK 16 will go out of support when JDK 17 is released in 12 months
(Sept 2021).
- JDK 17 will be the next LTS version assuming that's confirmed and
not changed in the next 12 months.

Due to a non-LTS version only being supported for 6 months, I would be
surprised if any non critical fixes will be addressed and will simply
be forward patches into the next version and tested there. I'm not
expecting fixes to be backported to non-LTS versions, and a criteria
based approach to deciding what backport happens from say JDK 15 to
JDK 11.

OpenJDK offers installation files for Linux, so you can do a tar
install directly from https://jdk.java.net/14/. So when a new version
is released, you can install it yourself.

If you are wanting to do a debian "sudo apt-get install
openjdk-15-jdk-headless" then it comes down to each linux distribution
and the approach they have taken. Some have 3rd party user contributed
repositories where the latest is available, some I suspect are
maintained by JDK contributors to make their own lives or testing
easier. But in general I would say as Java has now classified non-LTS
and LTS versions. I would be surprised if a LTS linux release would
take on a non-LTS release. But a non-LTS linux release or one with a
rolling release, they might take on a non-LTS version. Another issue
is the linux distribution might have different cut off dates, so they
might have the last non-LTS version.

All above is my personal version and from using Java and OpenJDK what
I understand about the current situation.

I'm also looking at upgrading from Java 1.8 as the base. We have a
develop branch on JDK 1.8, branched off to create feature/java11 and
similar for feature/java14. By the end of september feature/java14
will be upgraded to feature/java15. These branches have
module-info.java and CICD selecting that JDK version and other minor
JDK CICD specific patches. We decided against using a matrix build
approach as we control the Java version where the application is
deployed.

We keep cascading rebasing the feature/javaX branches so changes from
develop are tested against the newer Java versions. If CICD doesn't
pass we review the issues and feed that back into how we are
developing code. So we can continually tweak our pattern,
dependencies, structure or style. So it took about 10 rebases and 3
month to get the feature/java11 branch to pass on CICD, but only about
1 day of total direct effort was related to JDK 11, which was doing
the rebases and reviewing CICD output. As we drip feed the fixes in
whilst doing other development. Yes it took a long ish time, but
because we had no actual dedicated budget for upgrading to JDK 11 from
JDK 1.8, so similar to your best money from upgrade budget.

OpenJDK User
John

On Mon, 31 Aug 2020 at 12:05, Ben Evans <benjamin.john.evans at gmail.com> wrote:
>
> Hi Steven,
>
> As part of my day job (Architect for JVM technologies at New Relic) I
> produced this report:
> https://blog.newrelic.com/technology/state-of-java/ back in March
>
> It's based on the actual observations of which JVMs our customers are
> running in production. We see data from 10s of millions of JVMs every
> day.
>
> The pattern is clear - very few companies are choosing to use the
> versions of Java that are not long-term support releases (Java 8 and
> 11 are the only LTS releases currently. Java 13 is not LTS and is
> already EOL).
>
> The numbers have moved a bit - we now see 15-20% of users running Java
> 11 and ~80% running Java 11, but the general pattern remains the same.
>
> The most popular distribution for Java 11 that provides ongoing
> updates for free is AdoptOpenJDK - https://adoptopenjdk.net/ - which
> is becoming part of the Eclipse Foundation. If you are heavy users of
> AWS you may also want to consider Amazon Corretto.
>
> Thanks,
>
> Ben
>
> On Mon, 31 Aug 2020 at 07:27, <syates at stevendyates.com> wrote:
> >
> >
> > Hi OpenJDK Mailing list, I am reaching out as I would be interested in
> > some general advice and items for consideration when upgrading our
> > existing Java 8 adoption to either the OpenJdk 11.* or OpenJdk 13.*.
> > My manager has told me she wants to get the best value for her upgrade
> > dollars so the version of Java we choose would ideally be supported
> > for as long as possible (min 5-6 years) with bugfixes, security
> > patches etc.
> >
> > Also with OpenJDK, how does the patching process work. i.e. If a bug /
> > vulnerability is discovered, do these fixes get rolled up and
> > distributed to the major Linux distros as part of their regular
> > patching cycle? WOuld be interested in how the process works plus any
> > guidance you may have would be appreciated. Thank you kindly. :)
> >
> > Sincerely
> > Steven Yates
> >