On Sat, 2018-11-03 at 21:41 -0700, Wei wrote: > Thanks everyone! I checked the system metrics during the optimization > process. CPU usage is quite low, there is no I/O wait, and memory > usage is not much different from before the docValues change. So I > wonder what could be the bottleneck.
Are you looking at overall CPU usage or single-core? When we run force merge, we have a single core at 100% while the rest are idle. NB: There is currently a thread "Static index, fastest way to do forceMerge" in the Lucene users mailinglist, which seem to be quite parallel to this thread. - Toke Eskildsen, royal Danish Library
