Janus: a framework to boost HPC applications in the cloud based on SDN path provisioning

Data centers, clusters, and grids have historically supported High-Performance Computing (HPC) applications. Due to the high capital and operational expenditures associated with such infrastructures, we have witnessed consistent efforts to run HPC applications in the cloud in the recent past. The potential advantages of this shift include higher scalability and lower costs. If, on the one hand, app instantiation—through customized Virtual Machines (VMs)—is a well-solved issue, on the other, the network still represents a significant bottleneck. When switching HPC applications to be executed on the cloud, we lose control of where VMs will be positioned and of the paths that will be traversed for processes to communicate with one another. To bridge this gap, we present Janus, a framework for dynamic, just-in-time path provisioning in cloud infrastructures. By leveraging emerging software-defined networking principles, the framework allows for an HPC application, once deployed, to have interprocess communication paths configured upon usage based on least-used network links (instead of resorting to shortest, pre-computed paths). Janus is fully configurable to cope with different operating parameters and communication strategies, providing a rich ecosystem for application execution speed up. Through an extensive experimental evaluation, we provide evidence that the proposed framework can lead to significant gains regarding runtime. Moreover, we show what one can expect in terms of system overheads, providing essential insights on how better benefiting from Janus.

     

Task scheduling algorithms for energy optimization in cloud environment: a comprehensive review

Cluster Computing - Cloud computing is very popular because of its unique features such as scalability, elasticity, on-demand service, and security. A large number of tasks are performed...     

Characterizing an invasion assemblage: first comparison of insect communities on native and introduced subspecies of Phragmites australis in Ontario,Canada

Biological Invasions - Introduced Phragmites (Phragmites australis ssp. australis) forms part of an invasion assemblage in North America that includes non-native insect herbivores and parasitoids,...     

Climate Records,Isotopes, and C:N Stoichiometry Reveal Carbon and Nitrogen Flux Dynamics Differ Between Functional Groups of Ectomycorrhizal Fungi

Ecosystems - A major functional division in ectomycorrhizal fungi is between taxa with hydrophobic ectomycorrhizae (strong proteolytic capabilities, deep nitrogen (N) acquisition, and extensive...     

Biotechnology of virus eradication and plant vaccination in phytobiome context

A plant’s associated biota plays an integral role in its metabolism, nutrient uptake, stress tolerance, pathogen resistance and other physiological processes. Although a virome is an integral part of the phytobiome, a major contradiction exists between the holobiont approach and the practical need to eradicate pathogens from agricultural crops. In this review, we discuss grapevine virus control, but the issue is also relevant for numerous other crops, including potato, cassava, citrus, cacao and other species. Grapevine diseases, especially viral infections, cause main crop losses. Methods have been developed to eliminate viruses and other microorganisms from plant material, but elimination of viruses from plant material does not guarantee protection from future reinfection. Elimination of viral particles in plant material could create genetic drift, leading in turn to an increase in the occurrence of pathogenic strains of viruses. A possible solution may be a combination of virus elimination and plant propagation in tissue culture with in vitro vaccination. In this context, possible strategies to control viral infections include application of plant resistance inducers, cross protection and vaccination using siRNA, dsRNA and viral replicons during plant ‘cleaning’ and in vitro propagation. The experience and knowledge accumulated in human immunization can help plant scientists to develop and employ new methods of protection, leading to more sustainable and healthier crop production.     

Robert J. Marquis and Suzanne Koptur (eds): Caterpillars in the Middle. Tritrophic Interactions in a Changing World

Journal of Insect Conservation -     

Meta-analysis Reveals Different Competition Effects on Tree Growth Resistance and Resilience to Drought

Ecosystems - Drought will increasingly threaten forest ecosystems worldwide. Understanding how competition influences tree growth response to drought is essential for forest management aiming at...     

Comparative Endocranial Anatomy,Encephalization, and Phylogeny of Notoungulata (Placentalia,Mammalia)

Journal of Mammalian Evolution - Cranial endocasts are one of the most direct tools available to obtain information about the endocranial cavity of fossil mammals, but few anatomical comparisons...     

Reclassification of aortic stenosis by fusion of echocardiography and computed tomography in low-gradient aortic stenosis

Netherlands Heart Journal - The integration of computed tomography (CT)-derived left ventricular outflow tract area into the echocardiography-derived continuity equation results in the...