On Thu, 2017-03-02 at 15:39 +0000, Caruana, Matthew wrote: > Thank you. The question remains however, if this is such a hefty > operation then why is it walking to the destination instead of > running, so to speak?
We only do optimize on an old Solr 4.10 setup, but for that we have plenty of experience. At least for single-shard, and at least for most of the work, optimize is a single-threaded process: It takes us ~8 hours to optimize a ~900GB shard using SSDs, with 1 CPU-core at near 100% and the other ones not doing anything. The machine load number is a bit fuzzy, but if you do a top doing optimization, my guess is that you will see the same thing as we do: Only 1 CPU-core working. --Â Toke Eskildsen, Royal Danish Library
