Nishant Saurabh

The paper “Semantics-aware Virtual Machine Image Management in IaaS Clouds” has been accepted for publication at 33rd IEEE International Parallel & Distributed Processing Symposium , IPDPS 2019 to be held at Rio de Janerio, Brazil (May 20-24 2019).

Authors: Nishant Saurabh (Alpen-Adria Universität Klagenfurt), Julian Remmers (University of Innsbruck), Dragi Kimovski (Alpen-Adria Universität Klagenfurt), Radu Prodan (Alpen-Adria Universität Klagenfurt), Jorge G. Barbosa (LIACC, Faculdade de Engenharia da Universidade do Porto).

Abstract: Infrastructure-as-a-service (IaaS) Clouds concurrently accommodate diverse sets of user requests, requiring an efficient strategy for storing and retrieving virtual machine images (VMIs) at a large scale. The VMI storage management require dealing with multiple VMIs, typically in the magnitude of gigabytes, which entails VMI sprawl issues hindering the elastic resource management and provisioning. Nevertheless, existing techniques to facilitate VMI management overlook VMI semantics (i.e at the level of base image and software packages) with either restricted possibility to identify and extract reusable functionalities or with higher VMI publish and retrieval overheads. In this paper, we design, implement and evaluate Expelliarmus, a novel VMI management system that helps to minimize storage, publish and retrieval overheads. To achieve this goal, Expelliarmus incorporates three complementary features. First, it makes use of VMIs modelled as semantic graphs to expedite the similarity computation between multiple VMIs. Second, Expelliarmus provides a semantic aware VMI decomposition and base image selection to extract and store non-redundant base image and software packages. Third, Expelliarmus can also assemble VMIs based on the required software packages upon user request. We evaluate Expelliarmus through a representative set of synthetic Cloud VMIs on the real test-bed. Experimental results show that our semantic-centric approach is able to optimize repository size by 2.2-16 times compared to state-of-the-art systems (e.g. IBM’s Mirage and Hemera) with significant VMI publish and retrieval performance improvement.

Keyword: Virtual machine image management, semantic similarity, storage optimization
Acknowledgement: The The Austrian Research Promotion Agency (FFG, grant agreement 848448, Tiroler Cloud) and the European Union (Horizon 2020 research and innovation program, grant agreement 644179, ARTICONF) funded this work.

Nishant Saurabh

The poster “Towards a semantic-centric VMI repository management” has been accepted for presentation at PhD forum event of 33rd IEEE International Parallel & Distributed Processing Symposium, IPDPS 2019 to be held at Rio de Janerio, Brazil (May 20-24 2019)

Authors: Nishant Saurabh (Alpen-Adria Universität Klagenfurt), Radu Prodan (Alpen-Adria Universität Klagenfurt)

Wer schafft mehr Rechenoperation pro Sekunde? Hochleistungsrechner sind ein wichtiges Werkzeug im Lösen wissenschaftlicher Probleme. HIER der aktuelle Standard Artikel – ein Interview mit Prof. Radu Prodan.

Christian Timmerer

Authors: Raimund Schatz (AIT Austrian Institute of Technology), Anatoliy Zabrovskiy (Alpen-Adria Universität Klagenfurt), Christian Timmerer(Alpen-Adria Universität Klagenfurt, Bitmovin Inc.)
Abstract: Omnidirectional video (ODV) streaming applications are becoming increasingly popular. They enable a highly immersive experience as the user can freely choose her/his field of view within the 360-degree environment. Current deployments are fairly simple but viewport-agnostic which inevitably results in high storage/bandwidth requirements and low Quality of Experience (QoE). A promising solution is referred to as tile- based streaming which allows to have higher quality within the user’s viewport while quality outside the user’s viewport could be lower. However, empirical QoE assessment studies in this domain are still rare. Thus, this paper investigates the impact of different tile-based streaming approaches and configurations on the QoE of ODV. We present the results of a lab-based subjective evaluation in which participants evaluated 8K omnidirectional video QoE as influenced by different (i) tile-based streaming approaches (full vs. partial delivery), (ii) content types (static vs. moving camera), and (iii) tile encoding quality levels determined by different quantization parameters. Our experimental setup is characterized by high reproducibility since relevant media delivery aspects (including the user’s head movements and dynamic tile quality adaptation) are already rendered into the respective processed video sequences. Additionally, we performed a complementary objective evaluation of the different test sequences focusing on bandwidth efficiency and objective quality metrics. The results are presented in this paper and discussed in detail which confirm that tile-based streaming of ODV improves visual quality while reducing bandwidth requirements.

Index Terms: Omnidirectional Video, Tile-based Streaming, Subjective Testing, Objective Metrics, Quality of Experience

Acknowledgment: This work was supported in part by the Austrian Research Promotion Agency (FFG) under the Next Generation Video Streaming project “PROMETHEUS”.

Link: https://www.qomex2019.de/

ITEC is delighted to announce the next speaker in our guest lecture series – Ass.-Prof. Ali C. Beğen from Ozyegin University, Istanbul, Turkey. The course will take place April 1-12, 2019. This course introduces different types of applications that enhance the world of multimedia and the Web, and the systems and data structures that are used by them.

For more information on the course, click HERE.

ITEC is delighted to announce the next speaker in our guest lecture series – PD Dr. Ralf Klamma from RWTH Aachen University. The course will take place from June 12-19, 2019.

This course presents an introduction to Augmented Reality, with emphasis on designing and developing Augmented Reality applications. For more information on the course, click HERE.

 

 

The Institute of Information Technology at the Alpen-Adria-Universität Klagenfurt invites applications for Post-Doctoral Research Positions (100% employment) within the Christian Doppler (CD) Pilot Laboratory ATHENA “Adaptive Streaming over HTTP and Emerging Networked Multimedia Services” ATHENA-JobApplication PostDoc

The Institute of Information Technology at the Alpen-Adria-Universität Klagenfurt invites applications for Doctoral Student Positions (100% employment) within the Christian Doppler (CD) Pilot Laboratory ATHENA “Adaptive Streaming over HTTP and Emerging Networked Multimedia Services” ATHENA-JobApplication