Balancing Overused and Above Average Bins
Describes how to balance highly utilized Overused and Above Average bins.
Storage pools in the Overused and Above Average bins are highly utilized. The default
threshold of “overused” is 90%, which means that the first overused bin’s lower bound is 90%.
You should in normal circumstances, never reset this threshold, but you can, if necessary, by
setting the value for the parameter cldb.balancer.disk.overused.threshold
using the maprcli config save
command. For example:
maprcli config save -values {"cldb.balancer.disk.overused.threshold":"95"}
In scenarios where the cluster average is low, storage pools in Above Average bins too might
not be highly utilized. In this case, to prevent unnecessary balancing activity, disk balancer
uses an additional criterion to prevent wasted moves: only those storage pools whose
utilization equals to or is greater than a certain threshold are considered for balancing.
This threshold is controlled by the configurable parameter
cldb.balancer.disk.threshold.percentage
, whose default value is 70%.
cldb.balancer.disk.threshold.percentage
parameter
is also applicable to Overused bins also.