Hi everyone,
I would like to propose raising the minimum Java version for Apache
Parquet Java from 11 to 17. Java 17 is the current baseline LTS
version and has been out since September 2021 -- nearly four years.
The broader ecosystem has already converged on Java 17 as the
minimum:
- Apache Spark 4.x requires Java 17 (dropped Java 8/11).
- Apache Flink 2.x uses Java 17 by default and recommends it as the
version to run on.
- Apache Hadoop 3.5+ requires JDK 17 on the server side.
- Apache Hive 4.2 requires JDK 21 as the minimum.
As a library consumed by all of the above, Parquet Java staying on
Java 11 provides diminishing returns while imposing real costs:
1. Build tooling compatibility. We already hit issues where the
Spotless formatter and Hadoop itself break on newer JDKs due to
removed APIs (Subject.getSubject() in JDK 23+, internal javac
methods in JDK 25). Staying on Java 11 as the baseline makes it
harder to test and support the JDK versions our consumers
actually run on.
2. Language and API improvements. Java 17 brings records, sealed
classes, text blocks, pattern matching for instanceof, etc. These
improve code readability and reduce boilerplate.
3. Performance. The JVM has had significant improvements in GC
(ZGC, Shenandoah), JIT compilation, and memory layout between
Java 11 and 17. Libraries compiled against a Java 17 baseline can
take advantage of these without workarounds.
4. Security. Java 11 no longer receives public security
updates. Requiring 17 aligns with the security posture expected
of a widely deployed data format library.
The first commit on the PR [1] already enforces Java 17 via the Maven
enforcer plugin and removes pre-17 workarounds (reflection hacks for
DirectByteBuffer cleanup, etc.). The full build passes on JDK 17, 21,
and 25.
I don't expect this to be controversial given where the ecosystem is,
but wanted to give the community a chance to discuss before we merge.
Thoughts?
[1] https://github.com/apache/parquet-java/pull/3579
Best,
Ismael
P.S. My excuses if this has already been discussed. I could not find a
related issue / thread.
