Tripod: Towards a Scalable, Efficient and Resilient Cloud Gateway

Cloud gateways are fundamental components of a cloud platform, where various network functions (e.g., L4/L7 load balancing, network address translation, stateful firewall, and SYN proxy) are deployed to process millions of connections and billions of packets. Providing high-performance and failure-resilient packet processing with a scalable traffic management mechanism is crucial to ensuring the quality of service of a cloud provider, and hence is of great importance. Many network functions nowadays are implemented in software with commodity servers for low cost and high flexibility. However, existing software-based network function frameworks oftentimes provide part of these features, while cannot satisfy all three requirements above simultaneously. To address these issues, in this paper, we introduce TRIPOD, a novel network function framework specialized for cloud gateways. Having identified the fundamental limitations of loosely coupling traffic , processing logic and state , TRIPOD jointly manages these three elements with the unique characteristics of cloud gateways, which is enabled by a simple, efficient traffic processing mechanism , and a high performance state management service . Adopting several effective techniques and optimizations, TRIPOD is able to achieve scalable traffic management (<100 flow rules for even ~Tbps traffic), high performance (reducing 40% of latency compared with state of the art) and failure resilience (similar packet/connection loss rate compared to state of the art), with reasonable overheads (less than 10% of the workload traffic) even under an extremely heavy traffic, making it a good fit for cloud gateways.