Balancing 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 not 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 when 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%.

Note: If the threshold of the Overused bin is set below the default value of 90%, the balancing threshold is also applicable to Overused bins also. That is, the balancing threshold specified in the cldb.balancer.disk.threshold.percentage parameter is applicable to Above Average bins and to Overused bin, if the Overused bin’s threshold falls below 90%.