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165
A Middleware for Self-Managing Large-Scale Systems
, 2006
"... Abstract — Resource management poses particular challenges in large-scale systems, such as server clusters that simultaneously process requests from a large number of clients. A resource management scheme for such systems must scale both in the in the number of cluster nodes and the number of applic ..."
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Abstract — Resource management poses particular challenges in large-scale systems, such as server clusters that simultaneously process requests from a large number of clients. A resource management scheme for such systems must scale both in the in the number of cluster nodes and the number of applications the cluster supports. Current solutions do not exhibit both of these properties at the same time. Many are centralized, which limits their scalability in terms of the number of nodes, or they are decentralized but rely on replicated directories, which also reduces their ability to scale. In this paper, we propose novel solutions to request routing and application placementtwo key mechanisms in a scalable resource management scheme. Our solution to request routing is based on selective update propagation, which ensures that the control load on a cluster node is independent of the system size. Application placement is approached in a decentralized manner, by using a distributed algorithm that maximizes resource utilization and allows for service differentiation under overload. The paper demonstrates how the above solutions can be integrated into an overall design for a peerto-peer management middleware that exhibits properties of selforganization. Through complexity analysis and simulation, we show to which extent the system design is scalable. We have built a prototype using accepted technologies and have evaluated it using a standard benchmark. The testbed measurements show that the implementation, within the parameter range tested, operates efficiently, quickly adapts to a changing environment and allows for effective service differentiation by a system administrator. Index Terms — autonomic computing, self-organization, decentralized control, service differentiation I.
Abbadi. On Hit Inflation Techniques and Detection in Streams of Web Advertising Networks
- In Proceedings of the 27th IEEE ICDCS International Conference on Distributed Computing
, 2006
"... Click fraud is jeopardizing the industry of Internet advertising. Internet advertising is crucial for the thriving of the entire Internet, since it allows producers to advertise their products, and hence contributes to the well being of ecommerce. Moreover, advertising supports the intellectual valu ..."
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Cited by 9 (3 self)
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Click fraud is jeopardizing the industry of Internet advertising. Internet advertising is crucial for the thriving of the entire Internet, since it allows producers to advertise their products, and hence contributes to the well being of ecommerce. Moreover, advertising supports the intellectual value of the Internet by covering the running expenses of the content publishers ’ sites. Some publishers are dishonest, and use automation to generate traffic to defraud the advertisers. Similarly, some advertisers automate clicks on the advertisements of their competitors to deplete their competitors’ advertising budgets. In this paper, we describe the advertising network model, and discuss the issue of fraud that is an integral problem in such setting. We propose using online algorithms on aggregate data to accurately and proactively detect automated traffic, preserve surfers ’ privacy, while not altering the industry model. We provide a complete classification of the hit inflation techniques; and devise stream analysis techniques that detect a variety of fraud attacks. We abstract detecting the fraud attacks of some classes as theoretical stream analysis problems that we bring to the data management research community as open problems. A framework is outlined for deploying the proposed detection algorithms on a generic architecture. We conclude by some successful preliminary findings of our attempt to detect fraud on a real network. 1.
Price of Anarchy in Non-Cooperative Load Balancing
"... We investigate the price of anarchy of a load balancing game with K dispatchers. The service rates and holding costs are assumed to depend on the server, and the service discipline is assumed to be processor-sharing at each server. The performance criterion is taken to be the weighted mean number of ..."
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We investigate the price of anarchy of a load balancing game with K dispatchers. The service rates and holding costs are assumed to depend on the server, and the service discipline is assumed to be processor-sharing at each server. The performance criterion is taken to be the weighted mean number of jobs in the system, or equivalently, the weighted mean sojourn time in the system. Independently of the state of the servers, each dispatcher seeks to determine the routing strategy that optimizes the performance for its own traffic. The interaction of the various dispatchers thus gives rise to a non-cooperative game. For this game, we first show that, for a fixed amount of total incoming traffic, the worst-case Nash equilibrium occurs when each player routes exactly the same amount of traffic, i.e., when the game is symmetric. For this symmetric game, we provide the expression for the loads on the servers at the Nash equilibrium. Using this result we then show that, for a system with two or more servers, the price of anarchy, which is the worst-case ratio of the global cost of the Nash equilibrium to the global cost of the centralized setting, is lower bounded by K/(2 √ K − 1) and upper bounded by √ K, independently of the number of servers. Keywords: atomic games, load balancing, processor sharing, price of anarchy.
A Walk through Content Delivery Networks
- LECTURE NOTES IN COMPUTER SCIENCE
"... Abstract. Content Delivery Networks (CDN) aim at overcoming the inherent limitations of the Internet. The main concept at the basis of this technology is the delivery at edge points of the network, in proximity to the request areas, to improve the user’s perceived performance while limiting the cost ..."
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Cited by 8 (2 self)
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Abstract. Content Delivery Networks (CDN) aim at overcoming the inherent limitations of the Internet. The main concept at the basis of this technology is the delivery at edge points of the network, in proximity to the request areas, to improve the user’s perceived performance while limiting the costs. This paper focuses on the main research areas in the field of CDN, pointing out the motivations, and analyzing the existing strategies for replica placement and management, server measurement, best fit replica selection and request redirection. 1
Fault-tolerant and scalable TCP splice and web server architecture
- Reliable Distributed Systems, 2006. SRDS ’06. 25th IEEE Symposium on
, 2006
"... This paper describes three enhancements to the TCP splicing mechanism: (1) Enable a TCP connection to be simultaneously spliced through multiple machines for higher scalability; (2) Make a spliced connection fault-tolerant to proxy failures; and (3) Provide flexibility of splitting a TCP splice betw ..."
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This paper describes three enhancements to the TCP splicing mechanism: (1) Enable a TCP connection to be simultaneously spliced through multiple machines for higher scalability; (2) Make a spliced connection fault-tolerant to proxy failures; and (3) Provide flexibility of splitting a TCP splice between a proxy and a backend server for further increasing the scalability of a web server system. A web server architecture based on this enhanced TCP splicing is proposed. This architecture provides a highly scalable, seamless service to the users with minimal disruption during server failures. In addition to the traditional web services in which users download webpages, multimedia files and other types of data from a web server, the proposed architecture supports newly emerging web services that are highly interactive, and involve relatively longer, stateful client server sessions. A prototype of this architecture has been implemented as a Linux 2.6 kernel module, and the paper presents important performance results measured from this implementation. 1
Nuccio: “Kernel-based Web switches providing content-aware routing
- IEEE NCA
, 2003
"... Locally distributed Web server systems represent a cost-effective solution to the performance problems due to high traffic volumes reaching popular Web sites. In this paper, we focus on architectures based on layer-7 Web switches because they allow a much richer set of possibilities for the Web site ..."
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Cited by 6 (1 self)
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Locally distributed Web server systems represent a cost-effective solution to the performance problems due to high traffic volumes reaching popular Web sites. In this paper, we focus on architectures based on layer-7 Web switches because they allow a much richer set of possibilities for the Web site architecture, at the price of a scalability much lower than that provided by a layer-4 switch. In this paper, we compare the performance of three solutions for layer-7 Web switch: a two-way application-layer architecture, a two-way kernel-based architecture, and a one-way kernel-based architecture. We show quantitatively how much better the one-way architecture performs with respect to a two-way scheme, even if implemented at the kernel level. We conclude that an accurate implementation of a layer-7 Web switch may become a viable solution to the performance requirements of the majority of cluster-based information systems. 1
Fine grain performance evaluation of e-commerce sites
- ACM Performance Evaluation Review
, 2004
"... E-commerce sites are still a reference for the Web technology in terms of complexity and performance requirements, including availability and scalability. In this paper we show that a coarse grain analysis, that is used in most performance studies, may lead to incomplete or false deductions about th ..."
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Cited by 6 (5 self)
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E-commerce sites are still a reference for the Web technology in terms of complexity and performance requirements, including availability and scalability. In this paper we show that a coarse grain analysis, that is used in most performance studies, may lead to incomplete or false deductions about the behavior of the hardware and software components supporting e-commerce sites. Through a fine grain performance evaluation of a medium size e-commerce site, we find some interesting results that demonstrate the importance of an analysis approach that is carried out at the software function level with the combination of distribution oriented metrics instead of average values. 1
Towards autonomic service provisioning systems,” Cluster Computing and the Grid
- IEEE International Symposium on
, 2010
"... Abstract — This paper discusses our experience in building SPIRE, an autonomic system for service provision. The architecture consists of a set of hosted Web Services subject to QoS constraints, and a certain number of servers used to run sessionbased traffic. Customers pay for having their jobs run ..."
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Abstract — This paper discusses our experience in building SPIRE, an autonomic system for service provision. The architecture consists of a set of hosted Web Services subject to QoS constraints, and a certain number of servers used to run sessionbased traffic. Customers pay for having their jobs run, but require in turn certain quality guarantees: there are different SLAs specifying charges for running jobs and penalties for failing to meet promised performance metrics. The system is driven by an utility function, aiming at optimizing the average earned revenue per unit time. Demand and performance statistics are collected, while traffic parameters are estimated in order to make dynamic decisions concerning server allocation and admission control. Different utility functions are introduced and a number of experiments aiming at testing their performance are discussed. Results show that revenues can be dramatically improved by imposing suitable conditions for accepting incoming traffic; the proposed system performs well under different traffic settings, and it successfully adapts to changes in the operating environment. I.
Load prediction models in Web-based systems
"... Run-time management of modern Web-based services requires the integration of several algorithms and mechanisms for job dispatch-ing, load sharing, admission control, overload detection. All these algorithms should take decisions on the basis of present and/or fu-ture load conditions of the system re ..."
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Run-time management of modern Web-based services requires the integration of several algorithms and mechanisms for job dispatch-ing, load sharing, admission control, overload detection. All these algorithms should take decisions on the basis of present and/or fu-ture load conditions of the system resources. In particular, we ad-dress the issue of predicting future resource loads under real-time constraints in the context of Internet-based systems. In this situa-tion, it is extremely difficult to deduce a representative view of a system resource from collected raw measures that show very large variability even at different time scales. For this reason, we propose a two-step approach that first aims to get a representative view of the load trend from measured raw data, and then applies a load pre-diction algorithm to load trends. This approach is suitable to sup-port different decision systems even for highly variable contexts and is characterized by a computational complexity that is com-patible to run-time decisions. The proposed models are applied to a multi-tier Web-based system, but the results can be extended to other Internet-based contexts where the systems are characterized by similar workloads and resource behaviors. 1.
Simultaneous Scheduling of Replication and Computation for Bioinformatic Applications on the Grid
- IN PROC. OF WORKSHOP ON CHALLENGES OF LARGE APPLICATIONS IN DISTRIBUTED ENVIRONMENTS ( CLADE 2005
, 2005
"... One of the first motivations of using grids comes from applications managing large data sets in field such as high energy physics or life sciences. To improve the global through-put of software environments, replicas are usually put at wisely selected sites. Moreover, computation requests have to be ..."
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Cited by 5 (1 self)
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One of the first motivations of using grids comes from applications managing large data sets in field such as high energy physics or life sciences. To improve the global through-put of software environments, replicas are usually put at wisely selected sites. Moreover, computation requests have to be scheduled among the available resources. To get the best performance, scheduling and data replication have to be tightly coupled. However, there are few approaches that provide this coupling. This paper presents an algorithm that combines data management and scheduling using a steady-state approach. Our theoretical results are validated using simulation and
