G1 parallel old gen collection

kirk at kodewerk.com kirk at kodewerk.com
Tue Oct 4 20:20:23 UTC 2016


> I’m currently trying to run some Twitter services with G1 and the results are encouraging but not good enough.  One issue is that full GCs take much longer than with ParallelOld (3-4x longer).

Can you provide a GC log?
> Tony said that G1’s old collection is not parallel.

It is serial.

> Is that still the case in JDK 9?  If yes, is someone at Oracle working on parallelizing it?

This is the case in JDK 9. But you should not see a Full GC with a properly configured collector with a well behaved application.

Kind regards,
Kirk Pepperdine 

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