access_time 01 de julho de 2019 às 15:00 até 01 de julho de 2019 às 17:00
place Sala 0.17, Pavilhão de Informática II do IST, Alameda
Composing and scheduling workflows at Internet scale require communication and coordination across various services in heterogeneous execution environments - from data centers and clouds to the edge environments operated by multiple service providers. Services are diverse and inclusive of several variants such as web services, network services, and data services. Service description standards and protocols focus on interoperability across service interfaces, to enable workflows spanning various service providers. Nevertheless, in practice, standardization of the interfaces remains mostly limited. Furthermore, efficient resource provisioning for workflows of several users from multiple infrastructures requires collaboration and cooperation of the infrastructure providers. The current approaches are limited in scalability and optimality in efficiently provisioning resources for user workflows spanning numerous infrastructure providers. Network Softwarization revolutionizes the network landscape in various stages, from building, incrementally deploying, and maintaining the environment. Software-Defined Networking (SDN) and Network Functions Virtualization (NFV) are two core tenets of network softwarization. SDN offers a logically centralized control plane by abstracting away the control of the network devices in the data plane. NFV virtualizes dedicated hardware middleboxes and deploys them on top of servers and data centers as network functions. Thus, network softwarization enables efficient management of the system, by enhancing its control and improving the reusability of the network services. In this work, we aim at exploiting network softwarization to compose workflows of distinct services, in heterogeneous infrastructures, ranging from data centers to the edge. We thus intend to mitigate the challenges concerning resource management and interoperability of heterogeneous infrastructures, to efficiently compose service workflows, while sharing the network and the computing resources across several users. To this end, we propose three significant contributions. First, we extend SDN in cloud and data center environments to unify various phases of development and deploy the workloads seamlessly, from simulations and emulations to physical deployment environments. We further extend this work to support multiple Service Level Agreements (SLAs) across diverse network flows in the data centers, by selectively enforcing redundancy on the network flows. Thus, we aim for Quality of Service (QoS) and efficient resource provisioning, while adhering to the policies of the users. Finally, we design a cloud-assisted overlay network, as a latency-aware virtual connectivity provider. Consequently, we propose cost-efficient data transfers at Internet scale, by separating the network from the infrastructure. Second, we propose a scalable architecture to compose service chains in wide area networks efficiently. We extend SDN and Message-Oriented Middleware (MOM), for a logically centralized composition and execution of service workflows. We thus propose a Software-Defined Service Composition (SDSC) framework for web service compositions, Network Service Chains (NSCs), and a network-aware execution of data services. We further present Software-Defined Systems (SDS) consisting of virtual network allocation strategies for multi-tenant service executions in large-scale networks comprised of multiple domains. Third, we investigate how our proposed SDS can operate efficiently for real-world application scenarios of heterogeneous infrastructures. While traditionally web services are built following standards and best practices such as Web Services Description Language (WSDL), network services and data services offered by different service providers often fall short in providing common Application Programming Interfaces (APIs), often resulting in vendor lock-in. We look into facilitating interoperability across service implementations and deployments, to enable seamless migrations. We propose big data applications and smart environments such as Cyber-Physical Systems (CPS) and the Internet of Things (IoT) as our two application scenarios. We thus build CPS and big data applications as composable service chains, offering them an interoperable execution.
local_offer Prova de Doutoramento
person Candidato: Pradeeban Kathiravelu
supervisor_account Orientador: Prof. Luís Manuel Antunes Veiga