Ivan, How about renaming it to hashFunctionScore? This will be more digestable to users. "segmentFillVariance" sounds too scientific even to me.
D. On Tue, Jul 18, 2017 at 10:39 AM, Ivan Rakov <ivan.glu...@gmail.com> wrote: > Hello Igniters, > > I want to propose one more method for memory metrics - > segmentFillVariance, float value from 0.0 to 1.0. > > Motivation: when persistence is enabled, we split memory policy into K > equal segments (K = concurrency level). We calculate hash of pageId to > determine segment where page will be stored. > Pages eviction to disk starts when segment is full. If hash function is > bad enough, one segment can overflow when there are lots of free space, and > evictions can start too early. We want to be able to distinguish such > situations. > > I propose to calculate segmentFillVariance as difference between maximum > and minimum percentage of segment fill. Greater variance signals about > worse hash function. > > Thoughts? > > -- > Best Regards, > Ivan Rakov > >
