Dynamic Cloud Allocation by Managing Web Services and by Implementing Portfolio Thinking and Design Diversity

Web services have gained growing interest due to their importance in developing Business to Business (B2B) or web applications. Simultaneously, cloud computing promises the delivery of reliable, affordable and on-demand services, which can be leased or traded. The popularity of the cloud and its distinctive economies of scale computation advantages make a cloud-based market a plausible and attractive option for publishing and trading web services. Conversely, offering web services through a cloud-based market has underlying risks associated with probable service failure – for instance, because of undependable service provision of the cloud service provider, hardware malfunctions or unpredicted fluctuations in demands for the traded service as a shared resource, etc. All these factors may increase the risks associated with Service Level Agreement (SLA) violations for web applications benefiting from the cloud-based market. Our work views the cloud as a marketplace for trading in-stances of web services, which web applications can explore trade and use as substitutable and compassable entities in the architecture of cloud-based service applications.