Adaptive packet filters

Adaptive packet filters (APFs) are motivated by the proliferation of distributed servers and the lack of quality-of-service (QoS) management solutions for them. APFs merge packet-filtering and server load monitoring into a novel load-sensitive packet-filtering abstraction for overload protection and QoS differentiation. They integrate well into network protocol stacks and firewalls, scale to large server farms while remaining completely transparent to the applications. Experimental results of our prototype implementation demonstrate APFs' efficacy in providing QoS differentiation and overload protection with minimal overheads.