This commit modifies the build to require JDK 9 for
compilation. Henceforth, we will compile with a JDK 9 compiler targeting
JDK 8 as the class file format. Optionally, RUNTIME_JAVA_HOME can be set
as the runtime JDK used for running tests. To enable this change, we
separate the meaning of the compiler Java home versus the runtime Java
home. If the runtime Java home is not set (via RUNTIME_JAVA_HOME) then
we fallback to using JAVA_HOME as the runtime Java home. This enables:
- developers only have to set one Java home (JAVA_HOME)
- developers can set an optional Java home (RUNTIME_JAVA_HOME) to test
on the minimum supported runtime
- we can test compiling with JDK 9 running on JDK 8 and compiling with
JDK 9 running on JDK 9 in CI
We disable these tests because the JVM flags we use will not start with
JDK 10. Since we do not support running these old versions on newer JDKs
anyway, this commit disables testing of these when running on JDK 10.
In windows we can't reliable git the pid so we skip the
reindex-from-remote tests from old versions of elasticsearch. This
is OK because we aren't really testing windows here anyway. It isn't
great, but should be safe.
Two of the versions of Elasticsearch we need to run for these tests
can't run in Java 9 so we skip the entire test if we are running in
java 9. For now. I'd like to reenable it to run against java 8 if
there is one available, but that can wait for another time.
Relates to #24561
Adds tests for reindex-from-remote for the latest 2.4, 1.7, and
0.90 releases. 2.4 and 1.7 are fairly popular versions but 0.90
is a point of pride.
This fixes any issues those tests revealed.
Closes#23828Closes#24520
Jason Tedor
Nik Everett