Various embodiments of the present disclosure relate to a cache stickiness index for providing measurable metrics associated with caches of a content delivery networking system. In one embodiment, a method for generating a cache stickiness index, including a cluster stickiness index and a region stickiness index, is disclosed. In embodiments, the cluster stickiness index is generated by comparing cache keys shared among a plurality of front-end clusters. In embodiments, the region stickiness index is generated by comparing cache keys shared among a plurality of data centers. In one embodiment, a system comprising means for generating a stickiness index is disclosed.