Interact hosting centers serve multiple service sites from a common hardware base. This paper presents the design and implementation of an architecture for resource management in a hosting center op-erating system, with an emphasis on energy as a driving resource management issue for large server clusters. The goals are to provi-sion server resources for co-hosted services in a way that automati-cally adapts to offered load, improve the energy efficiency of server dusters by dynamically resizing the active server set, and respond to power supply disruptions or thermal events by degrading service in accordance with negotiated Service Level Agreements (SLAs). Our system is based on an economic approach to managing shared server resources, in which services "bid " for resources as a func-tion of delivered performance. The system continuously moni-tors load and plans resource allotments by estimating the value of their effects on service performance. A greedy resource allocation algorithm adjusts resource prices to balance supply and demand, allocating resources to their most efficient use. A reconfigurable server switching infrastructure directs request traffic to the servers assigned to each service. Experimental results from a prototype confirm that the system adapts to offered load and resource avail-ability, and can reduce server energy usage by 29 % or more for a typical Web workload. 1.

Disk schedulers in current operating systems are generally work-conserving, i.e., they schedule a request as son as the previous request has finished. Such schedulers often require multiple outstanding requests from each process to meet system-level goals of performance and quality of service. Unfortunately, many common applications issue disk read requests in a synchronous manna% interspersing successive requests with shor periods of computation. The scheduler chooses the next request too early; this induces deceptive idleness, a condition where the scheduler incorrectly assumes that the test request issuing process has no further requests, and becomes forced to switch to a toques? from another pro- Ce3S.

Proportional-share resource management is becoming increasingly important in today's computing environments. In particular, the growing use of the computational resources of central service providers argues for a proportional-share approach that allows resource principals to obtain allocations that reflect their relative importance. In such environments, resource principals must be isolated from one another to prevent the activities of one principal from impinging on the resource rights of others. However, such isolation limits the flexibility with which resource allocations can be modified to reflect the actual needs of applications. We present extensions to the lottery-scheduling resource management framework that increase its flexibility while preserving its ability to provide secure isolation. To demonstrate how this extended framework safely overcomes the limits imposed by existing proportional-share schemes, we have implemented a prototype system that uses the framework to manage...

Services that share a storage system should realize the same efficiency, within their share of time, as when they have the system to themselves. The Argon storage server explicitly manages its resources to bound the inefficiency arising from inter-service disk and cache interference in traditional systems. The goal is to provide each service with at least a configured fraction (e.g., 0.9) of the throughput it achieves when it has the storage server to itself, within its share of the server—a service allocated 1�nth of a server should get nearly 1�nth (or more) of the throughput it would get alone. Argon uses automaticallyconfigured prefetch/write-back sizes to insulate streaming efficiency from disk seeks introduced by competing workloads. It uses explicit disk time quanta to do the same for non-streaming workloads with internal locality. It partitions the cache among services, based on their observed access patterns, to insulate the hit rate each achieves from the access patterns of others. Experiments show that, combined, these mechanisms and Argon’s automatic configuration of each achieve the insulation goal. 1

Distributed multimedia applications will be an important part of tomorrow's application mix and require appropriate operating system (OS) support. Neither hard real-time solutions nor best-effort solutions are directly well suited for this support. One reason is the coexistence of real-time and best effort requirements in future systems. Another reason is that the requirements of multimedia applications are not easily predictable, like variable bit rate coded video data and user interactivity. In this article, we present a survey of new developments in OS support for (distributed) multimedia systems, which include: (1) development of new CPU and disk scheduling mechanisms that combine real-time and best effort in integrated solutions; (2) provision of mechanisms to dynamically adapt resource reservations to current needs; (3) establishment of new system abstractions for resource ownership to account more accurate resource consumption; (4) development of new file system structures; (5) ...

To allow continuous media applications ne-grained control over their CPU allocations, and to protect these allocations from each other, thread priorities must have quality-of-service (QoS) interpretation. To this end, we present a CPU scheduler based on the well-dened resource specication of service curve. Service curve is distinguished from the traditional notion of rate by its ability to exibly decouple delay and rate performance. Apart from how we compute thread priorities, predictable performance is hard to achieve also because threads can interact with each other and contend for synchronization resources. Such interactions can contribute to various forms of priority inversion. We discuss a new approach of dynamic priority inheritance in our CPU scheduler that solves priority inversion due to lock contention. To solve priority inversion arising from incompatible client/server resource specications, we employ a train abstraction that allows a thread of control to visit multiple...

Proportional-share resource management is becoming increasingly important in today's computing environments. In particular, the growing use of the computational resources of central service providers argues for a proportional-share approach that allows clients to obtain resource shares that reflect their relative importance. In such environments, clients must be isolated from one another to prevent the activities of one client from impinging on the resource rights of others. However, such isolation limits the flexibility with which resource allocations can be modified to reflect the actual needs of clients. We present extensions to the lottery-scheduling resource-management framework that increase its flexibility while preserving its ability to provide secure isolation. To demonstrate how this extended framework safely overcomes the limits imposed by existing proportional -share schemes, we have implemented a prototype system that uses the framework to manage CPU time, physical memory,...

dsn,tsp¡ This paper overviews results from our recent work on building customized system software support for Distributed Shared Memory Multiprocessors. The mechanisms and policies outlined in this paper are connected with a single conceptual thread: they all attempt to reduce the memory latency of parallel programs by optimizing critical system services, while hiding the complex architectural details of Distributed Shared Memory from the programmer. We present four techniques that exhibit solid performance improvements: Efficient memory management for lightweight multithreading, highly scalable hybrid synchronization primitives, a virtual memory management scheme for DSM systems and transparent operating system services for adapting parallel programs to multiprogrammed environments. 1.

Future routers will not only forward data packets, but also provide value-added services such as security, accounting, caching and resource management. These services can be implemented as general programs, to be invoked by traversing packets embedding router program calls. Software programmable routers pose new challenges in the design of router operating systems (OS). First, router programs will require access to diverse system resources. The resource demands of a large community of heterogeneous resource consumers must either be coordinated to enable cooperation or arbitrated to resolve competition. Second, it is beneficial to concurrently support multiple virtual machines, each with a guaranteed share of physical resources. This allows services to be customized and to seamlessly evolve. We present the design and implementation of a next generation router OS that can meet the above challenges. We define an orthogonal kernel abstraction of Resource Allocation, which can schedule var...

This paper describes the design and implementation of a component based distributed multimedia application that was developed to investigate a new design principle for resource-effcient layered system architectures. In order to provide fexible and adaptable application scenarios, different applications are composed from four basic generic component types. Combining different component types with different types of interaction and locating them on different nodes of a distributed system then results in large distributed multimedia applications where each application has ifferent types of sophisticated resource requirements. Beyond the scope of our test-bed we believe that this componentbased architecture is well suited for general large scale streaming media applications such as video-conferencing and video on demand services.