Unexplained Jumps In Response Time "Fixed" By Disabling Tiered Compilation

Andrew Dinn adinn at redhat.com
Fri May 27 09:39:36 UTC 2016


On 25/05/16 15:33, James Lent wrote:
  . . .
> I then tried turning off Tiered Compilation (without changing the
> default Code Cache size) in dev and the problem went away.  Of course it
> is hard to prove a negative.  We are now testing in production with good
> results (over 40 hours of good performance).
> 
> Any thoughts?  I realize this is not much to go on, but, I thought I
> would report my issue just in case you get other reports like this and
> you start to see a pattern.

Have you tried turning on listing compiles with -XX:+PrintCompilation?

It would be very interesting to see what sort of compile activity is
going on around the time that the jumps in response times occur. A
comparison between +TieredCompilation and -ToetredCompilation might be
very informative.

regards,


Andrew Dinn
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