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Large datacenter operators with sites at multiple locations dimension their key resources according to the peak demand of the geographic area that each site covers. The demand of specific areas follows strong diurnal patterns with high peak to valley ratios that result in poor average utilization across a day. In this paper, we show how to rescue unutilized(More)
The difficulty of scaling Online Social Networks (OSNs) has introduced new system design challenges that has often caused costly re-architecting for services like Twitter and Facebook. The complexity of interconnection of users in social networks has introduced new scalability challenges. Conventional vertical scaling by resorting to full replication can be(More)
In a multi-level cache such as those used for web caching, a hit at level l leads to the caching of the requested object in all intermediate caches on the reverse path (levels l − 1,. .. , 1). This paper shows that a simple modification to this de facto behavior, in which only the l − 1 level cache gets to store a copy, can lead to significant performance(More)
— Large scale hierarchical caches for web content have been deployed widely in an attempt to reduce delivery delays and bandwidth consumption and also to improve the scalability of content dissemination through the world wide web. Irrespectively of the specific replacement algorithm employed in each cache, a de facto characteristic of contemporary(More)
Motivated by increased concern over energy consumption in modern data centers, we propose a new, distributed computing platform called Nano Data Centers (NaDa). NaDa uses ISP-controlled home <i>gateways</i> to provide computing and storage services and adopts a managed peer-to-peer model to form a distributed data center infrastructure. To evaluate the(More)
Many emerging scientific and industrial applications require transferring multiple Tbytes of data on a daily basis. Examples include pushing scientific data from particle accelerators/colliders to laboratories around the world, synchronizing data-centers across continents, and replicating collections of high definition videos from events taking place at(More)
The chronic lymphocytic leukemia (CLL) immunoglobulin repertoire is biased and characterized by the existence of subsets of cases with closely homologous ("stereotyped") complementarity-determining region 3 (CDR3) sequences. In the present series, 201 (21.9%) of 916 patients with CLL expressed IGHV genes that belonged to 1 of 48 different subsets of(More)
This paper presents an assessment of the communication overheads of IPsec and evaluates the feasibility of deploying it on handheld devices for the UMTS architecture. A wide range of different cryptographic algorithms are used in conjunction with IPsec, such as Data Encryption Standard (DES), Advanced Encryption Standard (AES), Message Digest (MD5) and(More)
Recent revelations that ISPs selectively manipulate P2P traffic have sparked much public discussion. Underlying this issue is the misalignment of interests between consumers on one hand who desire bulk transfers at flat rates, and ISPs on the other hand who are bound by budget and capacity constraints. Our thesis is that much of the tension can be(More)
This paper studies a resource allocation problem in a graph, concerning the joint optimization of capacity allocation decisions and object placement decisions, given a single capacity constraint. This problem has applications in internet content distribution and other domains. The solution to the problem comes through a multi-commodity generalization of the(More)