How do I verify that they are actually better? Is the overall performance of my program better? Because that's what I care about. I of course do include memory usage in "performance".
At almost every other case: G1 (the default, just don't add any flags).
Do you want to trade off using less memory at the price of some throughput? Decrease heap size, otherwise don't add anything.
That's it, in most cases just use the default.
They are not. Feel free to look up literally any half-decent benchmarks. If Java's on par or better than any other language of note, check the memory usage. It's standard for Java to have 5-20x the memory usage for about the same performance. The memory floor also seems to be in the hundreds of megabytes. Ridiculous.
> For example, in web servers a lot of work is request-response, so it's convenient to utilize generational GCs (so that each request data would fit into "young" generation).
No, that's a job for arenas. Generational GCs are mostly a result of Java's limitations, and not a univerally good approach.
> Go's GC is not generational though, so you should care about allocations.
You should always care about allocations. In fact, the idea that you shouldn't is a big part of Java's poor performance and design.
I'm not sure it's even better than Java's, especially for modern ZGC (and you can choose your GC in Java). Definitely less configurable. I would say most of online comments about Java's GC are long outdated.
For example, in web servers a lot of work is request-response, so it's convenient to utilize generational GCs (so that each request data would fit into "young" generation). Similar to arenas, but without code changes. Go's GC is not generational though, so you should care about allocations.
https://codemia.io/blog/path/The-Evolution-of-Garbage-Collec...