SPACE4Cloud short tutorial

SPACE4Cloud short tutorial

h2. Objective of this tutorial

Cloud Computing is assuming a relevant role in the ICT world, changing the way applications are designed, developed, and operated.

The cloud offers many useful services which application developers and operators can rely upon, but the adoption of such services requires specific expertise. As a matter of fact, given the heterogeneous technology offer and the pricing models currently available in the cloud market it is extremely complex and time consuming to design a cloud application choosing the most suitable services in order to fit functional and non-functional requirements while providing the best Quality of Service (QoS) and costs trade-offs Such situation calls for an integrated approach and special tools to guide designers, developers and operators through the adoption of specific cloud solutions. Within the framework of MODAClouds EU FP7 project, we propose, following the directives of Model-Driven Engineering, a state-of-the-art IDE (Creator 4Clouds) to design, by means of three levels of meta-models, a cloud application both in terms of architecture (components, interfaces, relationships) and QoS, expressing cloud-specific attributes and constraints. Among other things, such models include architectural and QoS constraints (e.g., VM utilisation or average application response time are lower than given thresholds), and a user-defined workload [5], necessary to assess both performance and cost of the application under different load conditions.

Creator 4Clouds seamlessly interfaces with SPACE 4Clouds, the tool this tutorial focuses on, which has been specially designed for the assessment and optimisation of QoS characteristics for Cloud applications. It allows software architects to analyse and optimise cloud applications during the early stages of design and implementation. Internally it employs performance models and and a metaheuristic engine to explore the space of cloud service alternatives seeking for the configuration that minimises the leasing costs of resources while meeting the QoS requirements.

These two tools, used together, represent a powerful Decision Support System at the service of the application designer, allowing him/her to make informed decisions and, ultimately, save time and money.