Ashish Gupta

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A key function for network traffic monitoring and analysis is the ability to perform aggregate queries over multiple data streams. Change detection is an important primitive which can be extended to construct many aggregate queries. The recently proposed sketches are among the very few that can detect heavy changes online for high speed links, and thus(More)
Traffic anomalies such as failures and attacks are increasing in frequency and severity, and thus identifying them rapidly and accurately is critical for large network operators. The detection typically treats the traffic as a collection of flows and looks for heavy changes in traffic patterns (<i>e.g.</i>, volume, number of connections). However,(More)
Virtual machine grid computing greatly simplifies the use of widespread computing resources by lowering the level of abstraction, benefiting both resource providers and users. For the user, the Virtuoso middleware that we are developing closely emulates the existing process of buying, configuring and using machines. VNET, a component of Virtuoso, is a(More)
A key function for network traffic monitoring and analysis is the ability to perform aggregate queries over multiple data streams. Change detection is an important primitive which can be extended to construct many aggregate queries. The recently proposed sketches (Krishnamurthy, 2003) are among the very few that can detect heavy changes online for high(More)
Resource borrowing is a common underlying approach in grid computing and thin-client computing. In both cases, external processes borrow resources that would otherwise be delivered to the interactive processes of end-users, creating contention that slows these processes and decreases the comfort of the end-users. How resource borrowing and user comfort are(More)
We propose a demonstration of extremely scalable modular robotics algorithms developed as part of the Claytronics Project (http://www-2.cs.cmu.edu/~claytronics/), as well as a demonstration of proof-of-concept prototypes. Our effort envisions multi-million-module robot ensembles able to morph into three-dimensional scenes, eventually with sufficient(More)
Virtual machine distributed computing greatly simplifies the use of widespread computing resources by lowering the level of abstraction, benefiting both resource providers and users. Towards that end our Virtuoso middleware closely emulates the existing process of buying, configuring and using physical machines. Virtuoso's VNET component is a simple and(More)
We are developing a distributed computing environment based on virtual machines featuring application monitoring, network monitoring, and an adaptive virtual network. In this paper, we describe our initial results in monitoring the communication traffic of parallel applications, and inferring its spatial communication properties. The ultimate goal is to be(More)
Experimental computer systems research typically ignores the end-user, modeling him, if at all, in overly simple ways. We argue that this (1) results in inadequate performance evaluation of the systems, and (2) ignores opportunities. We summarize our experiences with (a) directly evaluating user satisfaction and (b) incorporating user feedback in different(More)
With the ever-increasing link speeds and traffic volumes of the Internet, monitoring and analyzing network traffic usage becomes a challenging but essential service for network administrators of large ISPs or institutions. There are two popular primitives for efficient analysis over massive data streams: heavy hitter detection and heavy change detection.(More)