Improving cache performance of network intensive workloads

The performance of servers for network-intensive workloads such as web services and online transaction processing applications depends on the effective utilization of the processor caches. A detailed analysis of the cache space utilization of web workloads shows us that several memory addresses are referenced only once during their lifetime in the cache. These references frequently reside in the cache for a long time contributing to the pollution of cache. The most commonly adopted least-recently-used (LRU) replacement scheme does not exploit this characteristic. In this paper, we propose an alternative block replacement policy called Single-Touch Aware Replacement (STAR) algorithm. This algorithm predicts blocks that will potentially be referenced only once and replaces them early enough to improve cache efficiency. The STAR scheme was implemented in a trace-driven cache simulator and the performance with several commercial workloads was analyzed. The use of the STAR algorithm results in up to 20% improvement in cache performance for web workloads (SPECweb96, SPECweb99) and up to 5% improvement in online transaction processing (TPC-C) workloads.