Abstract. Cloud service offerings provide a competitive advantages to enterprises through flexible and scalable access to computing resources. With the recent advances in Cloud computing, the need is emerging for interoperability between Cloud services so that a complex and developed business applications on Clouds are interoperable. In fact, combining different independent Cloud services necessitates a uniform description format that facilitates the design, customization, and composition. In this context, Agent Interaction Protocols (IP) are a useful way for structuring communicative interaction among business partners, by organizing messages into relevant contexts and providing a common guide to the all parts. The challenge here is twofold. First, we must propose a formal model that is rich enough to capture interactions characteristics. Second, we must allow designers to combine existing protocols to achieve a new specific need.The work presented in this paper is considered as a first step toward Agent Interaction Protocols as a Service. In fact, we propose a basis for a theoretical approach for aggregating protocols to create a new desired business application. The proposed approach provides the underpinnings of aggregation abstractions for protocols. Also, it proposes a set of operators that allows the creation of new value-added protocols using existing ones as building blocks.Key words: Agent Interaction Protocols, Cloud Computing, Protocols Composition, Petri Net, Verification.
Introduction.Cloud computing is a model for enabling convenient, on demand network access to a shared pool of configurable computing resources that can be rapidly provisioned and released with a minimal management effort or service provider interaction [34]. According to the intended access methods and availability of Cloud computing environments, four major types of Cloud deployments are known: public Clouds, private Clouds, community Clouds, and hybrid Clouds [31].The increasing adoption rate of Cloud computing is currently driving developers, integrators and hosting enterprises to take Cloud computing into account. As a result, enterprises need to revise their current assets as Cloud computing is becoming a strategic asset.However, enterprises are driven by different reasons to maintain their own data center, such as legislation of storing data in-house, investments in the current infrastructure, or the extra latency and performance requirements. This drive is supported by the fact that enterprises have already invested heavily in their own private server equipment and software [21].Consequently, we believe that a hybrid approach makes more sense for enterprises. This approach allows one to use the internal infrastructure combined with public Cloud resources to build a hybrid Cloud. For example, on one hand, critical applications can run on the infrastructure/platform of the private data center, and, on the other hand, the public Cloud can be used as a solution to manage peak demands or for disaster recovery.While the different...