Yes, that thread waits (in the sense that nothing useful gets done), but during that time, from the perspective of the applications and OS, that CPU is busy: it is not "waiting" in such a way that you can dispatch a different process.
The point is, that if this was actually the problem, it would show up in a higher CPU utilization than the correspondent reported. -----Original Message----- From: Federico Fissore [mailto:feder...@fissore.org] Sent: Wednesday, September 28, 2011 2:04 PM To: solr-user@lucene.apache.org Subject: Re: strange performance issue with many shards on one server Jaeger, Jay - DOT, il 28/09/2011 18:40, ha scritto: > That would still show up as the CPU being busy. > i don't know how the program (top, htop, whatever) displays the value but when the cpu has a cache miss definitely that thread sits and waits for a number of clock cycles with 130GB of ram (per server?) I suspect caches miss as a rule just a suspicion however, nothing I'll bet on
