Hello,
we recently had a discussion on the dev mailing list for deprecating
support for Java 8 in 1.15, with a general consensus in favor of it.
I now wanted to check in with you, our users, to see what you have got
to say about that.
Why are we interested in deprecating Java 8 support now (and in
eventually removing it)?
The main reason is that supporting the recently released Java 17 (and
subsequent versions), while maintaining Java 8 support,
will be more complicated than if Java 11 were the oldest release
version. Essentially because Java 11/17 have both crossed the Java 9 chasm.
We will still have to bite this bullet in any case (because Java 17 is
out /now /but we are /not /dropping Java 8 /now/), but we would still
like to signal that users should upgrade to Java 11 so that we can
/eventually/ clean this up.
Furthermore, it is currently hard to justify investing time into
benchmarks/performance improvements that are specific to Java 11+, because
they provide no benefit to Java 8.
What does the deprecation mean exactly?
It will primarily mean that a warning will be logged when you run Flink
on Java 8.
We /may/ change the default Java version of the Docker images to Java 11
(the java8 tags will remain),
and we will put a larger emphasis on Flink's performance on Java 11.
Does that mean that Java 8 support will be removed in 1.16/1.17?
No. We are not putting a hard-date on the removal of Java 8 support at
this time.
Will this mean that at some point we'll surprise you with the
removal of Java 8 support in the next release?
No. We will announce the removal ahead of time by /at least/ half a year
/ 2+ releases (probably closer to a full year).
Is the deprecation already decided?
No. The responses in this thread are integral for deciding whether a
deprecation at this time makes sense.
If you are still using Java 8 at the moment, then we would appreciate if
you could tell us whether you already have a time-frame for
when you intend to upgrade to Java 11. We'd also be interested in
anything that blocks your migration to Java 11.
Please raise concerns you have, and feel free to ask questions.
