I noticed that while indexing, when commit happens, there is high disk read by Solr. The problem is that it is impacting search performance when the index is loaded from the disk with respect to the query, as the disk read speed is not quite good and the whole index is not cached in RAM.
When no searching is performed, I noticed that disk is usually read during commit operations and sometimes even without commit at low rate. I guess it is read due to segment merge operations. Can it be something else? If it is merging, can we limit disk IO during merging?
