A Protocol Development Framework for SLA Negotiations in Cloud and Service Computing

Abstract

As businesses transit towards cloud and service oriented economy, agents are employed to efficiently negotiate service level agreements (SLAs) on services procured automatically to match changes in demand. This ‘pay-as-you-go’ trading model affords flexibility with reliability, but requires customized and seamless interactions enabled by negotiation protocols that best serve the market domain. To this end, we present a domain-independent framework based on a protocol development lifecycle, comprising four distinct phases namely modeling, verification, rule-based implementation and generic execution. We illustrate all phases by introducing the Simple Bilateral Negotiation Protocol (SBNP) - a multi-tier, multi-round and customizable negotiation protocol. We exemplify its adoption among chains of service providers that serve SaaS, PaaS and IaaS offerings. We show that SBNP is well-formed, deterministic and deadlock-free. We evaluate state space scalability for SBNP and verify its correctness using Linear Temporal Logic (LTL). Finally, we show that rule-based implementation allows for generic execution of multiple protocols on our negotiation platform, which provides businesses the agility to sustain competitive advantage.