Ernani Azevedo

A path to automated service creation via semi-automation levels

The manual creation of new Internet- and IT-based applications is currently a limiting factor in enabling new and innovative services to be quickly available. We advocate that semi-automated service creation techniques are feasible, whereas fully automated ones are not a reality yet. Consistently increasing the level of automation may lead to a better comprehension of the problem that will pave the way for the introduction of higher levels of automation in the future. We have developed two versions of a service creation tool, with different levels of automation, which have so far confirmed our expectations that the experience with semi-automation is a promising approach for continually speeding up the service creation process.

Facilitating Service Creation via Partial Specification and Automated Composition

Service composition is an important feature enabled by Service Oriented Computing but it remains mainly a manual process. Proposals for complete or partial automation of composition exist, the majority relying on artificial intelligence-based planning, automated proof techniques, or graph-based solutions. Although sound, these approaches present practical issues that prevent their use in production scenarios. This paper presents a composition tool that allows for partial service specification along with a composition algorithm based on the semantic matching of services inputs and outputs. Early performance numbers are also presented.

E2ECloud: Composition and execution of end-to-end services in the cloud

The Internet has rapidly evolved, becoming a virtual place where it is simple to handle tasks that were known to be cumbersome or complex beforehand. However the development of new services remains a time consuming activity. This paper presents E2ECloud, a computing environment that allows the development of solutions for creation and provision of composite services in the cloud. Users create a new service through a SaaS tool, which generates a Service Code and deploys it onto an IaaS to be executed. A prototype of E2ECloud was developed and qualitative and quantitative evaluations were conducted, highlighting the potential of our approach to the creation of a new market for cloud service development.

Profiling core operations for elasticity in cloud environments

Cloud computing provides on-demand allocation and deallocation of resources via the key feature of elasticity. Although there are many choices of public and private clouds, detailed performance analysis for elasticity operations in such environments are not available. This paper compares the performance of core elasticity operations for the Amazon EC2 public cloud service with private clouds controlled by OpenNebula on top of Xen. Both public and private cloud environments are also compared against the Xen hypervisor alone. Our results show that elasticity can be provided by both cloud services with acceptable response times. We identified that EC2 is always faster than OpenNebula and sometimes even faster that our Xen setup.

An integrated composition model for collaboration in the cloud

Composition and virtualization are related concepts in scenarios where different entities collaborate for achieving a common goal. Such concepts have been presented in the literature as unrelated to each other. The reason might be the lack of both a unifying axis and a strong motivation. This paper presents an integrated model with concepts and technologies related to composition and virtualization (the axis) that are classified into different categories under the umbrella of cloud computing (the motivation). We offer an innovative view for improving the overall comprehension and the development of solutions for current complex ICT environments. As a result, we foresee cloud computing surviving the current hype and short-term business goals and becoming a long-lasting concept in computer science.

Adopting security routines in legacy organizations

Security is a well-known critical issue and exploitation of vulnerabilities is increasing in number, sophistication and damage. Furthermore, legacy systems tend to offer difficulty when upgrades are needed, specially when security recommendations are proposed. This paper presents a strategy for legacy systems based on three disciplines which guide the adoption of secure routines while avoid production drop. We present a prototype framework and discuss its success in providing security to the network of a power plant.

An adaptable storage slicing algorithm for content delivery networks

Several works study the performance of Content Delivery Networks (CDNs) under various network infrastructure and demand conditions. Some go even further while considering demand elasticity by leveraging on Cloud elasticity where each Content Service Provider (CSP) is served only the amount of storage space and network throughput that it needs and pays accordingly. Many of todays CDN implementations are based on these proposals. However, the allocation of virtual servers in cloud computing is not yet very fine-grained and suffers from limitations and time constraints for reallocation. This work proposes an efficient cache slicing mechanism that frees the CDN provider from dedicating a different virtual surrogate for each CSP in each location. This is achieved by dealing internally with the allocation space for each CSP in a shared surrogate, while still providing services in terms of network storage allowing a CSP to select and pay the amount of content that can be stored. We show that the proposed approach deals better with peak surrogate usage, and reduces the total network traffic by around 15% and cross-traffic by as much as 35% under some scenarios.

Analyzing strategies to effectively detect changes in content delivery networks

Content Delivery Networks have gained a popular role among application service providers (ASPs) and infrastructural companies. A CDN is an overlay network that gives more control of asset delivery by strategically placing servers closer to the enduser, reducing response time and network congestion. Many strategies have been proposed to deal with aspects inherent to the CDN distribution model. Though mostly very effective, a traditional CDN approach of statically positioned elements often fails to meet quality of experience (QoE) requirements when network conditions suddenly change. In this paper, we introduce a technique to detect significant changes in a monitored metric of a CDN in order to allow provisioning adaptation of resources, using easy access information with great practical viability. Results show decrease on network resources usage without considerable changes on quality of service (QoS). Furthermore, our technique has similar performance in comparison to an omniscient strategy.

Flexible Execution of Adaptable Composed Services

Dynamic system adaptation to continuously changing business requirements and environment conditions has been a common demand for IT over the last years. In spite of constant innovation in service computing, current technology is not able to keep up with business ever growing need faster time to market. The Service Refinement Cycle (SRC) has been proposed for providing flexibility and power for creating new services by composing existing services with integrated policies. We developed and deployed a Service Execution Environment (SEE) for the SRC using existing technology, such as Web Services, XACML and WS-BPEL. As a proof of concept prototype, we also developed an Online Radio Service that makes extensive use of the key SRC features and is executed by our SEE.

Tasks meet flows: Merging two paradigms in a Cloud applications development platform

In this paper we present a new architecture for the Cloud Integrator platform that extends it in two directions. The first one aimed at improving the way of an application can be defined by a developer. Instead of dealing with the burden of defining applications only by specifying semantic workflows in terms of activities expressed as a tuple <;task, object>, a developer can rely on the definition of complete executions flows or partial execution flows. The second extension aimed at the automatic deployment of applications in a cloud platform, thus allowing the simultaneous use of it by several clients over the Internet. We also present a proof-of-concept that illustrates the use of the cloud-based platform in a flight booking application.