This commit refactors the DataStreamDiagnostics class
achieving the following advantages:
- simpler code; by encapsulating the moving bucket histogram
into its own class
- better performance; by using an array to store the buckets
instead of a map
- explicit handling of gap buckets; in preparation of fixing #30080
The overall NOTICE file for the ML X-Pack module should
include the notices from the 3rd party C++ components as
well as the 3rd party Java components.
Tests need to wait for changes to the job's established memory usage to
propagate and an over enthusiastic optimisation meant jobs were updated
from stale state causing recent change to be lost.
Dimitris Athanasiou
David Roberts
David Kyle
Ryan Ernst