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%.