BinPacker.EqualNumBallAttributePerGroupObjective (bin_packer v0.1.0) View Source
This objective attempts to place balls into bins such that the given ball attribute is equally represented in each group of bins sharing the same bin attribute.
For example, in a cluster of computers, each housing many replicated data partitions, and one replica per partition is the "master", we'd use this objective to place an equal number of masters in each location.
This objective is a relaxed verion of the OnePerGroupConstraint, instead of being a hard constraint, it's a soft objective measured using the deviation of the number of ball attributes per group: https://en.wikipedia.org/wiki/Standard_deviation