NFV Platforms: Taxonomy, Design Choices and Future Challenges

Due to the intrinsically inefficient service provisioning in traditional networks, Network Function Virtualization (NFV) keeps gaining attention from both industry and academia. By replacing the purpose-built, expensive, proprietary network equipment with software network functions consolidated on commodity hardware, NFV envisions a shift towards a more agile and open service provisioning paradigm. During the last few years, a large number of NFV platforms have been implemented in production environments that typically face critical challenges, including the development, deployment, and management of Virtual Network Functions (VNFs). Nonetheless, just like any complex system, such platforms commonly consist of abounding software and hardware components and usually incorporate disparate design choices based on distinct motivations or use cases. This broad collection of convoluted alternatives makes it extremely arduous for network operators to make proper choices. Although numerous efforts have been devoted to investigating different aspects of NFV, none of them specifically focused on NFV platforms or attempted to explore their design space. In this paper, we present a comprehensive survey on the NFV platform design. Our study solely targets existing NFV platform implementations. We begin with a top-down architectural view of the standard reference NFV platform and present our taxonomy of existing NFV platforms based on what features they provide in terms of a typical network function life cycle. Then we thoroughly explore the design space and elaborate on the implementation choices each platform opts for. We also envision future challenges for NFV platform design in the incoming 5G era. We believe that our study gives a detailed guideline for network operators or service providers to choose the most appropriate NFV platform based on their respective requirements. Our work also provides guidelines for implementing new NFV platforms

Priority-Driven Differentiated Performance for NoSQL Database-As-a-Service

Designing data stores for native Cloud Computing services brings a number of challenges, especially if the Cloud Provider wants to offer database services capable of controlling the response time for specific customers. These requests may come from heterogeneous data-driven applications with conflicting responsiveness requirements. For instance, a batch processing workload does not require the same level of responsiveness as a time-sensitive one. Their coexistence may interfere with the responsiveness of the time-sensitive workload, such as online video gaming, virtual reality, and cloud-based machine learning. This paper presents a modification to the popular MongoDB NoSQL database to enable differentiated per-user/request performance on a priority basis by leveraging CPU scheduling and synchronization mechanisms available within the Operating System. This is achieved with minimally invasive changes to the source code and without affecting the performance and behavior of the database when the new feature is not in use. The proposed extension has been integrated with the access-control model of MongoDB for secure and controlled access to the new capability. Extensive experimentation with realistic workloads demonstrates how the proposed solution is able to reduce the response times for high-priority users/requests, with respect to lower-priority ones, in scenarios with mixed-priority clients accessing the data store

Joyce, Bakhtin, and postcolonial trialogue: history, subjectivity, and the nation in Ulysses

In the light of Bakhtinian theories, this research focuses on Ulysses as a postcolonial modernist text, in which Joyce appropriates modernist aesthetic strategies to serve the purpose of narrating the nation. Bakhtin is helpful here, not only because his theories serve especially well to explain the meeting and intersection of social, political, and cultural forces in periods of transition, but also because his attempt to establish a “historical poetics” helps both to explore discourse as social/individual ideology constituting the text and to interpret the dialogue interaction between sociohistorical forces and textual representation. As Bakhtin seeks to think through the issue of alterity and accentuates the all-importance of dialogue construction, his thought is useful for interpretation of Joyce-s endeavour to turn the hostility of binary opposition into polyphonic orchestration of heteroglossia. Mediating between such binary oppositions as Self and Other, private and public, inside and outside, the Joycean text demonstrates the importance of engagement with the past to transform its nightmarish impact into creative power for the composition of a postcolonial history; the significance of incorporating and negotiating dichotomies in a triangular structure and recognizing their coexistence for the constitution of a postcolonial subjectivity; and the consequence of integrating nationalist projects and cosmopolitan dimensions for the construction of a postcolonial nation. While Bakhtin sheds light on Joyce, Joyce complements what Bakhtin leaves unsaid, enlarging the scope and implication of Bakhtinian theories. The dialogue between the Irish author and the Russian thinker results in mutual enlightenment. The introductory chapter surveys the relationship between Joyce, Bakhtin, and postcolonial modernism, concentrating on the applicability of Bakhtinian concepts to the Joycean text. From the notion of the chronotope, the first chapter examines Stephen’s ambivalent attitude toward history, and focuses on his transformation of the past in the present time-space for the construction of a divergent and ongoing postcolonial future. The next chapter explores Bloom’s relation to colonial Irish society and inquiries into his shaping of an architectonic self, which results from the reaccentuation of public discourse and the mediation between individualism and collectivism. In the light of dialogism and grotesque realism, the third chapter deals with Molly’s dialogue answers to Bloom’s proposal of liberation, and investigates how her androgynously grotesque body transmits the external body, through her sexual body, into the textual body which is “Penelope.” The concluding chapter focuses on the interillumination of Joyce and Bakhtin: while Bakhtin helps refigure a postcolonial modernist Joyce, Joyce triangulates the binary structure of dialogue, underscoring the significance of trialogue as potential technique for postcolonial construction