Navraj Chohan

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MapReduce is a scalable and fault tolerant framework, patented by Google, for computing embarrassingly parallel reductions. Hadoop is an open-source implementation of Google MapReduce that is made available as a web service to cloud users by the Amazon Web Services (AWS) cloud computing infrastructure. Amazon Spot Instances (SIs) provide an inexpensive yet(More)
We present the design and implementation of AppScale, an open source extension to the Google AppEngine (GAE) Platform-asa-Service (PaaS) cloud technology. Our extensions build upon the GAE SDK to facilitate distributed execution of GAE applications over virtualized cluster resources, including Infrastructure-as-a-Service (IaaS) cloud systems such as(More)
In this paper, we present the design and implementation of Neptune, a domain specific language (DSL) that automates configuration and deployment of existing HPC software via cloud computing platforms. We integrate Neptune into a popular, open-source cloud platform, and extend the platform with support for user-level and automated placement of cloud services(More)
Software development for sensor network is made difficult by resource constrained sensor devices, distributed system complexity, communication unreliability, and high labor cost. Simulation, as a useful tool, provides an affordable way to study algorithmic problems with flexibility and controllability. However, in exchange for speed simulation often trades(More)
In this paper we present the design, implementation, and evaluation of a plug gable autoscaler within an open cloud platform-as-a-service (PaaS). We redefine high availability (HA) as the dynamic use of virtual machines to keep services available to users, making it a subset of elasticity (the dynamic use of virtual machines). This makes it possible to(More)
We present the design and implementation of AppScale, an open source extension to the Google AppEngine (GAE) Platform-as-a-Service (PaaS) cloud technology. Our extensions build upon the GAE SDK to facilitate distributed execution of GAE applications over Xen-based clusters, including Infrastructureas-a-Service (IaaS) cloud systems such as Amazon’s AWS/EC2(More)
A wireless sensor network (WSN) is comprised of resource constrained devices called motes. Motes are battery operated and must conserve as much power as possible. Power usage for each mote is made up of processing data, sensing the surroundings, and sending and receiving packets. The bulk of power usage for standard WSN applications lies in the radio where(More)
We present new cloud support that employs a single API -- the Datastore API from Google App Engine (GAE) -- to interface to different open source distributed database (DB) technologies. We employ this support to ``plug in'' DB technologies to the API so that they can be used by web applications and services without modification. The system facilitates an(More)
In this paper, we present the design and implementation of Neptune, a simple, domain-specific language based on the Ruby programming language. Neptune automates the configuration and deployment of scientific software frameworks over disparate cloud computing systems. Neptune integrates support for MPI, MapReduce, UPC, X10, StochKit, and others. We implement(More)
In this paper, we present and empirically evaluate the performance of database-agnostic transaction (DAT) support for the cloud. Our design and implementation of DAT is scalable, fault-tolerant, and requires only that the data store provide atomic, row-level access. Our approach enables applications to employ a single transactional data store API that can(More)