Results 1 - 10 of 239

Aurora: a new model and architecture for data stream management

by Daniel J. Abadi, Don Carney, Ugur Çetintemel, Mitch Cherniack, Christian Convey, Sangdon Lee, Michael Stonebraker, Nesime Tatbul, Stan Zdonik , 2003
"... This paper describes the basic processing model and architecture of Aurora, a new system to manage data streams for monitoring applications. Monitoring applications differ substantially from conventional business data processing. The fact that a software system must process and react to continual in ..."
Abstract - Cited by 391 (31 self) - Add to MetaCart
This paper describes the basic processing model and architecture of Aurora, a new system to manage data streams for monitoring applications. Monitoring applications differ substantially from conventional business data processing. The fact that a software system must process and react to continual inputs from many sources (e.g., sensors) rather than from human operators requires one to rethink the fundamental architecture of a DBMS for this application area. In this paper, we present Aurora, a new DBMS currently under construction at Brandeis University, Brown University, and M.I.T. We first provide an overview of the basic Aurora model and architecture and then describe in detail a stream-oriented set of operators.
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A Feedback-driven Proportion Allocator for Real-Rate Scheduling

by David Steere, Ashvin Goel, Joshua Gruenberg, Dylan Mcnamee, Calton Pu, Jonathan Walpole , 1999
"... In this paper we propose changing the decades-old practice of allocating CPU to threads based on priority to a scheme based on proportion and period. Our scheme allocates to each thread a percentage of CPU cycles over a period of time, and uses a feedback-based adaptive scheduler to assign automatic ..."
Abstract - Cited by 219 (27 self) - Add to MetaCart
In this paper we propose changing the decades-old practice of allocating CPU to threads based on priority to a scheme based on proportion and period. Our scheme allocates to each thread a percentage of CPU cycles over a period of time, and uses a feedback-based adaptive scheduler to assign automatically both proportion and period. Applications with known requirements, such as isochronous software devices, can bypass the adaptive scheduler by specifying their desired proportion and/or period. As a result, our scheme provides reservations to applications that need them, and the benefits of proportion and period to those that do not. Adaptive scheduling using proportion and period has several distinct benefits over either fixed or adaptive priority based schemes: finer grain control of allocation, lower variance in the amount of cycles allocated to a thread, and avoidance of accidental priority inversion and starvation, including defense against denial-of-service attacks. This paper descr...
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CPU Reservations and Time Constraints: Efficient, Predictable Scheduling of Independent Activities

by Michael B. Jones, Daniela Rosu, Marcel-Catalin Rosu , 1997
"... Workstations and personal computers are increasingly being used for applications with real-time characteristics such as speech understanding and synthesis, media computations and I/O, and animation, often concurrently executed with traditional non-real-time workloads. This paper presents a system th ..."
Abstract - Cited by 214 (7 self) - Add to MetaCart
Workstations and personal computers are increasingly being used for applications with real-time characteristics such as speech understanding and synthesis, media computations and I/O, and animation, often concurrently executed with traditional non-real-time workloads. This paper presents a system that can schedule multiple independent activities so that: . activities can obtain minimum guaranteed execution rates with application-specified reservation granularities via CPU Reservations, . CPU Reservations, which are of the form "reserve X units of time out of every Y units", provide not just an average case execution rate of X/Y over long periods of time, but the stronger guarantee that from any instant of time, by Y time units later, the activity will have executed for at least X time units, . applications can use Time Constraints to schedule tasks by deadlines, with on-time completion guaranteed for tasks with accepted constraints, and . both CPU Reservations and Time Constraints...

Cello: A Disk Scheduling Framework for Next Generation Operating Systems

by Prashant J. Shenoy, Harrick M. Vin - In Proceedings of ACM SIGMETRICS Conference , 1997
"... In this paper, we present the Cello disk scheduling framework for meeting the diverse service requirements of applications. Cello employs a two-level disk scheduling architecture, consisting of a classindependent scheduler and a set of class-specific schedulers. The two levels of the framework alloc ..."
Abstract - Cited by 195 (12 self) - Add to MetaCart
In this paper, we present the Cello disk scheduling framework for meeting the diverse service requirements of applications. Cello employs a two-level disk scheduling architecture, consisting of a classindependent scheduler and a set of class-specific schedulers. The two levels of the framework allocate disk bandwidth at two timescales: the class-independent scheduler governs the coarse-grain allocation of bandwidth to application classes, while the class-specific schedulers control the fine-grain interleaving of requests. The two levels of the architecture separate application-independent mechanisms from application-specific scheduling policies, and thereby facilitate the co-existence of multiple class-specific schedulers. We demonstrate that Cello is suitable for next generation operating systems since: (i) it aligns the service provided with the application requirements, (ii) it protects application classes from one another, (iii) it is work-conserving and can adapt to changes in wor...
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Cluster Reserves: A Mechanism for Resource Management in Cluster-based Network Servers

by Mohit Aron, Peter Druschel, Willy Zwaenepoel - In Proceedings of the ACM SIGMETRICS Conference , 2000
"... In network (e.g., Web) servers, it is often desirable to isolate the performance of different classes of requests from each other. That is, one seeks to achieve that a certain minimal proportion of server resources are available for a class of requests, independent of the load imposed by other reque ..."
Abstract - Cited by 165 (4 self) - Add to MetaCart
In network (e.g., Web) servers, it is often desirable to isolate the performance of different classes of requests from each other. That is, one seeks to achieve that a certain minimal proportion of server resources are available for a class of requests, independent of the load imposed by other requests. Recent work demonstrates how to achieve this performance isolation in servers consisting of a single, centralized node; however, achieving performance isolation in a distributed, cluster based server remains a problem. This paper introduces a new abstraction, the cluster reserve, which represents a resource principal in a cluster based network server. We present a design and evaluate a prototype implementation that extends existing techniques for performance isolation on a single node server to cluster based servers. In our design, the dynamic cluster-wide resource management problem is formulated as a constrained optimization problem, with the resource allocations on individual machin...
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Borrowed-Virtual-Time (BVT) scheduling: supporting latency-sensitive threads in a general-purpose scheduler

by Kenneth J. Duda, David R. Cheriton , 1999
"... Systems need to run a larger and more diverse set of applications, from real-time to interactive to batch, on uniprocessor and multiprocessor platforms. However, most schedulers either do not address latency requirements or are specialized to complex real-time paradigms, limiting their applicability ..."
Abstract - Cited by 153 (1 self) - Add to MetaCart
Systems need to run a larger and more diverse set of applications, from real-time to interactive to batch, on uniprocessor and multiprocessor platforms. However, most schedulers either do not address latency requirements or are specialized to complex real-time paradigms, limiting their applicability to general-purpose systems. In this paper, we present Borrowed-Virtual-Time (BVT) Scheduling, showing that it provides low-latency for realtime and interactive applications yet weighted sharing of the CPU across applications according to system policy, even with thread failure at the real-time level, all with a low-overhead implementation on multiprocessors as well as uniprocessors. It makes minimal demands on application developers, and can be used with a reservation or admission control module for hard real-time applications. 1 Introduction With modern processor speeds and memory capacities, systems can now run a wide diversity of application tasks, and they need to in order to meet us...

Adaptive control of virtualized resources in utility computing environments

by Pradeep Padala, Kang G. Shin, Xiaoyun Zhu Mustafa, Uysal Zhikui Wang, Sharad Singhal Arif, Kenneth Salem - In European Conference on Computer Systems , 2007
"... Data centers are often under-utilized due to over-provisioning as well as time-varying resource demands of typical enter-prise applications. One approach to increase resource uti-lization is to consolidate applications in a shared infrastruc-ture using virtualization. Meeting application-level quali ..."
Abstract - Cited by 153 (8 self) - Add to MetaCart
Data centers are often under-utilized due to over-provisioning as well as time-varying resource demands of typical enter-prise applications. One approach to increase resource uti-lization is to consolidate applications in a shared infrastruc-ture using virtualization. Meeting application-level quality of service (QoS) goals becomes a challenge in a consolidated environment as application resource needs differ. Further-more, for multi-tier applications, the amount of resources needed to achieve their QoS goals might be different at each tier and may also depend on availability of resources in other tiers. In this paper, we develop an adaptive resource con-trol system that dynamically adjusts the resource shares to individual tiers in order to meet application-level QoS goals while achieving high resource utilization in the data cen-ter. Our control system is developed using classical control theory, and we used a black-box system modeling approach to overcome the absence of first principle models for com-plex enterprise applications and systems. To evaluate our controllers, we built a testbed simulating a virtual data cen-ter using Xen virtual machines. We experimented with two multi-tier applications in this virtual data center: a two-tier implementation of RUBiS, an online auction site, and a two-tier Java implementation of TPC-W. Our results in-dicate that the proposed control system is able to maintain high resource utilization and meets QoS goals in spite of varying resource demands from the applications. Categories and Subject Descriptors C.4 [PERFORMANCEOF SYSTEMS]: [Modeling tech-
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Energy-Efficient Soft Real-Time CPU Scheduling for Mobile Multimedia Systems

by Wanghong Yuan, Klara Nahrstedt - Proc. Symp. Operating Systems Principles , 2003
"... This paper presents GRACE-OS, an energy-efficient soft real-time CPU scheduler for mobile devices that primarily run multimedia applications. The major goal of GRACE-OS is to support application quality of service and save energy. To achieve this goal, GRACE-OS integrates dynamic voltage scaling int ..."
Abstract - Cited by 145 (8 self) - Add to MetaCart
This paper presents GRACE-OS, an energy-efficient soft real-time CPU scheduler for mobile devices that primarily run multimedia applications. The major goal of GRACE-OS is to support application quality of service and save energy. To achieve this goal, GRACE-OS integrates dynamic voltage scaling into soft real-time scheduling and decides how fast to execute applications in addition to when and how long to execute them. GRACE-OS makes such scheduling decisions based on the probability distribution of application cycle de-mands, and obtains the demand distribution via online pro-filing and estimation. We have implemented GRACE-OS in the Linux kernel and evaluated it on an HP laptop with a variable-speed CPU and multimedia codecs. Our experi-mental results show that (1) the demand distribution of the studied codecs is stable or changes smoothly. This stability implies that it is feasible to perform stochastic scheduling and voltage scaling with low overhead; (2) GRACE-OS de-livers soft performance guarantees by bounding the dead-line miss ratio under application-specific requirements; and (3) GRACE-OS reduces CPU idle time and spends more busy time in lower-power speeds. Our measurement indi-cates that compared to deterministic scheduling and volt-age scaling, GRACE-OS saves energy by 7 % to 72 % while delivering statistical performance guarantees.
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Automated control of multiple virtualized resources

by Pradeep Padala, Kai-yuan Hou, Kang G. Shin, Xiaoyun Zhu, Vmware Inc, Mustafa Uysal, Zhikui Wang, Sharad Singhal, Arif Merchant , 2008
"... Virtualized data centers enable sharing of resources among hosted applications. However, it is difficult to satisfy servicelevel objectives (SLOs) of applications on shared infrastructure, as application workloads and resource consumption patterns change over time. In this paper, we present AutoCont ..."
Abstract - Cited by 112 (5 self) - Add to MetaCart
Virtualized data centers enable sharing of resources among hosted applications. However, it is difficult to satisfy servicelevel objectives (SLOs) of applications on shared infrastructure, as application workloads and resource consumption patterns change over time. In this paper, we present AutoControl, a resource control system that automatically adapts to dynamic workload changes to achieve application SLOs. AutoControl is a combination of an online model estimator and a novel multi-input, multi-output (MIMO) resource controller. The model estimator captures the complex relationship between application performance and resource allocations, while the MIMO controller allocates the right amount of multiple virtualized resources to achieve application SLOs. Our experimental evaluation with RUBiS and TPC-W benchmarks along with production-trace-driven workloads indicates that AutoControl can detect and mitigate CPU and disk I/O bottlenecks that occur over time and across multiple nodes by allocating each resource accordingly. We also show that AutoControl can be used to provide service differentiation according to the application priorities during resource contention.

SLIC: An extensibility system for commodity operating systems

by Douglas P. Ghormley, David Petrou, Thomas E. Anderson, Steven H. Rodrigues
"... Modern commodity operating systems are large and complex systems developed over many years by large teams of programmers, containing hundreds of thousands of lines of code. Consequently, it is extremely difficult to add significant new functionality to these systems. In response to this problem, a n ..."
Abstract - Cited by 106 (3 self) - Add to MetaCart
Modern commodity operating systems are large and complex systems developed over many years by large teams of programmers, containing hundreds of thousands of lines of code. Consequently, it is extremely difficult to add significant new functionality to these systems. In response to this problem, a number of recent research projects have explored novel operating system architectures to support untrusted extensions, including SPIN, VINO, Exokernel, and Fluke. Unfortunately, these architectures require substantialimplementation effort and are not generally available in commodity systems. In contrast, by leveraging the technique of interposition, we have designed and implemented a prototype extension system called SLIC which requires only trivial operating system
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