Sounds good! D.
On Jul 19, 2017, 1:54 PM, at 1:54 PM, Ivan Rakov <ivan.glu...@gmail.com> wrote: >Dmitriy, > >I agree, hashFunctionScore is more comprehensible. >I'd correct it to "pageHashFunctionScore" to make it clear that it's >about function that distributes pages, not about hashCode() of >user-provided keys. > >-- >Best Regards, >Ivan Rakov > >On 18.07.2017 19:34, Dmitriy Setrakyan wrote: >> 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 >>> >>>
