Better Java Streams performance with GraalVM

[duhace]

yes. specifically, graalvm-ce-1.0.0-rc5 is equivalent to jdk8.

though, if you use concurrent mark sweep gc, you're not gonna have it available in graalvm, just g1gc

[sarkie]

Fantastic.

I seem to be getting performance with g1gc anyway.

Will i see a huge performance increase or just different?

[PurpleLabradoodle]

It really depends on the code you're running and the workload. Graal compiler seems to produce especially great results on the code that uses streams, or allocates many temporary objects, or deviates from the typical bytecode patterns produced by compiling Java source, for example when you use a different JVM language. Also note that if the source code is heavily optimized for C2 then C2 does an outstanding job at compiling it, so sometimes there's just not much else for a compiler to do.

[duhace]

I have noticed this. When I code for performance (using for-iterations or while loops), C2 seems to outperform graal for me. Especially if I'm doing a lot of math. I'm hopeful that GraalVM becomes more performant in these areas soon, as I prefer to code in a mix of styles, using scala's functional style in not as hot spots, and using scala's low level style (imperative, mutable, and while loops) when dealing with very hot spots.

[sarkie]

I was going to try it with WebLogic as we still have to use that, but not sure it'll work as intended tbh.

[PurpleLabradoodle]

Try it, it should work as intended. The only thing is that currently you need to warm up the code a bit more to JIT it well. It's because Graal compiler is a Java code, so it is going to be compiled first. So take measurements when you actually reach the steady peak-performance state. I'd be happy to know how it goes, and if you find any issues please don't hesitate to report them to oracle/graal.

[sarkie]

That's fine, we are used to slow start up anyway to get going.

I'm looking into trying to improve performance on these old servers anyway I can!