4 ms·

Just a note, G1 probably still isn't ready for rock-solid production usage. E.g. bugs like this are still cropping up: https://bugs.openjdk.java.net/browse/JD

Just a note, G1 probably still isn't ready for rock-solid production usage. E.g. bugs like this are still cropping up: https://bugs.openjdk.java.net/browse/JDK-8148175 https://bugs.openjdk.java.net/browse/JDK-8148175 That's a pretty scary bug. Who knows how stuff like that will trash your data if you aren't properly checksumming everything. CMS and other GCs have the advantage of years of bug-squashing and tuning. G1 is exciting, but I wouldn't personally use it on anything important for quite some time.

gravypod 10y ago
That bug does not seem to effect Java 7, it only mentions 8u80 and 9. Still very bad though.
- polyfractal 10y ago
  Yep, just more recent versions, and it's been fixed too. But if you watch the bugs that keep popping up for G1 you see stuff like this fairly regularly. Of course, that's a totally unfair comparison: CMS has had a decade of bug squashing...I'm sure it had equally scary bugs when it was new. But that's the point. Don't use new, shiny GC's because they are still squishing bugs :) (Sorry, preaching to the choir, I just get frustrated by everyone claiming G1 will solve all their problems without investigating potential downsides)
  - needusername 10y ago
    Actually CMS is only five years older than G1. The first published papers for G1 are from 2004. But yes, G1 has a long history of scary bugs. There was a time a few years ago where practically every week a crashing bug was fixed. G1 addresses certain problem areas of CMS and replaces them with others. Honestly I hope in ten years from now we have better choices in HotSpot than CMS or G1 but right now it doesn't look like it (if you don't count Shenandoah with has other issues). Having that said I have recently seen G1 performing exceptionally well in production: 120ms GC pauses with a 120 MB/s sustained allocation rate with basically default settings (apart from GC logging).
kev009 10y ago
It seems semi-common to run HBase with G1GC now days.

gravypod 10y ago

That bug does not seem to effect Java 7, it only mentions 8u80 and 9. Still very bad though.

polyfractal 10y ago
Yep, just more recent versions, and it's been fixed too. But if you watch the bugs that keep popping up for G1 you see stuff like this fairly regularly. Of course, that's a totally unfair comparison: CMS has had a decade of bug squashing...I'm sure it had equally scary bugs when it was new. But that's the point. Don't use new, shiny GC's because they are still squishing bugs :) (Sorry, preaching to the choir, I just get frustrated by everyone claiming G1 will solve all their problems without investigating potential downsides)
- needusername 10y ago
  Actually CMS is only five years older than G1. The first published papers for G1 are from 2004. But yes, G1 has a long history of scary bugs. There was a time a few years ago where practically every week a crashing bug was fixed. G1 addresses certain problem areas of CMS and replaces them with others. Honestly I hope in ten years from now we have better choices in HotSpot than CMS or G1 but right now it doesn't look like it (if you don't count Shenandoah with has other issues). Having that said I have recently seen G1 performing exceptionally well in production: 120ms GC pauses with a 120 MB/s sustained allocation rate with basically default settings (apart from GC logging).

kev009 10y ago

It seems semi-common to run HBase with G1GC now days.