Is it possible that tuning garbage collection to achieve much better pause characteristics might actually *decrease* index performance?
Rebuilds that I did while still using a tuned CMS config would take between 5.5 and 6 hours, sometimes going slightly over 6 hours. A rebuild that I did recently with G1 took 6.82 hours. A rebuild that I did yesterday with further tuned G1 settings (which seemed to result in much smaller pauses than the previous G1 settings) took 8.97 hours, and that was on slightly faster hardware than the rebuild that took 6.82 hours. These rebuilds are done with DIH from MySQL. It seems completely counter-intuitive that settings which show better GC pause characteristics would result in indexing performance going down ... so can anyone shed light on this, tell me whether I'm out of my mind? Thanks, Shawn
