Also, 1ms is an eternity on modern hardware. That’s enough time to handle thousands of disk I/Os or network packets. That means each GC cycle can latency blip 1000’s of other machines.
Also, 1ms is an eternity on modern hardware
I hate to break it to you but malloc and free aren't instant either. Also ZGC can do less than 1msec pauses, often way less. At some point it just doesn't matter anymore for virtually all users.
That means each GC cycle can latency blip 1000’s of other machines.
Linux kernel timeslice is longer than 1 msec, so good luck if your server runs >1 process of any kind at all.
Failed at what exactly? People are happy with what he have now, and generally happier with every release (there have been some issues around G1 vs. the now-defunct CMS collector in some special circumstances). Netflix, Amazon, Apple, Google, and Twitter run much or most of their infrastructure on OpenJDK, without even using the newest collectors (AFAIK).
> Also, 1ms is an eternity on modern hardware.
That depends if you're looking at latency or throughput. Java's GCs have achieved good throughput a long time ago. But ZGC isn't a throughput collector; it is intended for online applications that aren't CPU bound. If you're serving transactions and your application pauses for no more than 1ms every few seconds you're probably OK. There are kernel subsystems that may cause a similar or higher worst-case blip.
In any event, Java is not intended for those who must get 100% of the performance the hardware can support, and are willing to pay a high price for getting there, nor is it intended for specialized, niche usage, where perfect performance is easy to achieve. It is intended to get to 95-98% performance at the lowest effort, for a wide variety of applications, and its main runtime cost now is in memory footprint. It's not intended to replace C/C++; we've got Zig for that.