S-Cache: Toward an Low Latency Service Caching for Edge Clouds

The next generation 5G cellular networks will include internet of things (IoT) networks. Moreover, network components are virtualized and running in virtual machines (VMs). Edge clouds, which are closer to end users, are leveraged to reduce end-to-end latency. However, the computational resources are limited in edge clouds, so to minimize overall service latency, it is crucial to determine carefully which services should be provided in edge clouds. In this paper, we propose a novel framework named Service Cache (S-Cache), which automatically caches popular services in edge clouds. In addition, we design a new cache replacement policy to maximize the cache hit rates. In our evaluation, we used real log files from Google and selected these files to form three datasets to evaluate the performance. We compared our cache replacement policy with Greedy-Dual-Size-Frequency (GDSF), Least-Frequently-Used (LFU) and other cache policies. The experimental results show that the cache hit rates are improved by 12% and 13% on average in two datasets and the total latency of our cache replacement policy is decreased by 113.8 seconds on average in the original order dataset, so our approach is superior to other existing cache policies and is more suitable in mobile edge computing environments.