On Thu, Nov 30, 2017 at 12:21 PM, Frank Swarbrick <
[email protected]> wrote:
> I have a heavy, perhaps unjustified prejudice, against Java and the JVM.
> I like "native compiled" languages, and I am very happy that IBM is looking
> to have Swift as another native compiled language on z/OS.
The z/OS Java SDK has both JIT and AOT compilation from java byte codes to
native machine instructions. Like it now? ;-)
I think that the performance of z/OS Java is pretty good.
My complaints:
- on z/OS, the startup costs (class loading and JITing time) required to
get a big application up and running efficiently. It has gotten better
though.
- the overhead and complexity of JNI
To generalize, Java applications are big and slow because of how they are
written - programmers glue together a bunch of very large frameworks
without much concern for resource usage.
In the past, there weren't decent profilers on z/OS, which makes this
worse. I haven't tried the new sampling profiler support for z/OS Java
yet ("Health Center") - has anyone?
Kirk Wolf
Dovetailed Technologies
http://dovetail.com
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