On Tue, 2017-03-14 at 16:47 +0200, Mahmoud Almokadem wrote: > After sorting with Self Time(CPU) I got that the > FSDirectory$FSIndexOutput$1.write() is taking much of CPU time, so > the bottleneck now is the IO of the hard drive? > > https://drive.google.com/open?id=0BwLcshoSCVcdb2I4U1RBNnI0OVU
I am not too sure how IO counts in VisualVM sampling mode. It is supposed to only measure CPU work. But I have had trouble with it in the past and since your screenshot shows a lot of time spend on fsync (which should take practically 0 Java CPU time), it seems that it is indeed IO-time. You can get a detailed breakdown by doing VisualVM profiling and doing a snapshot instead of sampling, but be prepared to restart your Solr afterwards as that is quite intrusive. Another (and simpler) option would be to check how much IO-wait there is with 'top' from a shell. - Toke Eskildsen, Royal Danish Library
