Designing Efficient Cooperative Caching Schemes for Multi-Tier Data-Centers over RDMA-enabled Networks

Caching has been a very important technique in improving the performance and scalability of web-serving datacenters. Research community has proposed cooperation of caching servers to achieve higher performance benefits. These existing cooperative cache designs often partially duplicate cached data redundantly on multiple servers for higher performance while optimizing the data-fetch costs for multiple similar requests. With the advent of RDMA enabled interconnects these cost estimates have changed the basic factors involved. Further, utilization of large scale of resources available across the tiers in todays multi-tier data-centers is of obvious importance. Hence, a systematic study of these various trade-offs involved is of paramount importance. In this paper, we present cooperative cache schemes that are designed to benefit in the light of the above mentioned trends. In particular, we design schemes taking advantage of RDMA capabilities of networks and multiple tier resources of modern multi-tier data-centers. Our designs are implemented on InfiniBand based clusters to work in conjunction with Apache based servers. Our experimental results show that our schemes show throughput improvement of up to 35% better than the basic cooperative caching schemes and 180% better than the simple single node caching schemes