摘要:
Methods and apparatus operating in a stream processing network perform load shedding and dynamic resource allocation so as to meet a pre-determined utility criterion. Load shedding is envisioned as an admission control problem encompassing source nodes admitting workflows into the stream processing network. A primal-dual approach is used to decompose the admission control and resource allocation problems. The admission control operates as a push-and-pull process with sources pushing workflows into the stream processing network and sinks pulling processed workflows from the network. A virtual queue is maintained at each node to account for both queue backlogs and credits from sinks. Nodes of the stream processing network maintain shadow prices for each of the workflows and share congestion information with neighbor nodes. At each node, resources are devoted to the workflow with the maximum product of downstream pressure and processing rate, where the downstream pressure is defined as the backlog difference between neighbor nodes. The primal-dual controller iteratively adjusts the admission rates and resource allocation using local congestion feedback. The iterative controlling procedure further uses an interior-point method to improve the speed of convergence towards optimal admission and allocation decisions.
摘要:
Methods and apparatus operating in a stream processing network perform load shedding and dynamic resource allocation so as to meet a pre-determined utility criterion. Load shedding is envisioned as an admission control problem encompassing source nodes admitting workflows into the stream processing network. A primal-dual approach is used to decompose the admission control and resource allocation problems. The admission control operates as a push-and-pull process with sources pushing workflows into the stream processing network and sinks pulling processed workflows from the network. A virtual queue is maintained at each node to account for both queue backlogs and credits from sinks. Nodes of the stream processing network maintain shadow prices for each of the workflows and share congestion information with neighbor nodes. At each node, resources are devoted to the workflow with the maximum product of downstream pressure and processing rate, where the downstream pressure is defined as the backlog difference between neighbor nodes. The primal-dual controller iteratively adjusts the admission rates and resource allocation using local congestion feedback. The iterative controlling procedure further uses an interior-point method to improve the speed of convergence towards optimal admission and allocation decisions.
摘要:
A system and method for resource allocation includes, in a network having nodes and links, injecting units of flow for at least one commodity at a source corresponding to the at least one commodity. At each node, queue heights, associated with the at least one commodity, are balanced for queues associated with each of one or more outgoing paths associated with that node. An amount of commodity flow is pushed across a link toward a sink, where the amount of commodity flow is constrained by a capacity constraint. Flow that reached the sink is absorbed by draining the queues.
摘要:
The present invention is based on the main ideas that different sub-intervals of a resource utilization time series are to be summarized with different granularity in the time axis, depending on the values of the series over that interval. Therefore, periods of high resource utilization are represented with higher time granularity, while periods of low resource utilization are represented with lower time granularity, the value stored can represent a function of the summarized values, such as the average or maximum value of the low resource utilization period. The captured resource utilization data is used to generate profiles, wherein the profiles summarize the historical utilization data. The profiles further capture pseudo-periodic behavior over different time scales.
摘要:
A method, computer program product, and data processing system for estimating and correcting the amount of clock skew in end-to-end network timing measurements is disclosed. Measured delays are combined with their time of measurement to create ordered pairs. These ordered pairs represent points within a Cartesian plane. The convex hull of these points is determined, and an optimal line segment from the resulting polygon is selected and extrapolated to create an affine function estimating clock skew over time. The optimal line segment of the polygon is one that optimizes a selected objective function. The objective function is selected so as to be an appropriate measurement of the accuracy of the resulting linear function as an estimate of the actual clock skew.
摘要:
The present invention is a method and an apparatus for estimating real-time travel times or traffic loads (e.g., traffic flows or densities) over a transportation network based on limited real-time data. In one embodiment, a method for estimating a travel time over a transportation network comprising at least a first link and a second link includes receiving a data feed associated with a real-time traffic flow over the first link, estimating a first travel time over the first link based at least in part on the data feed, and estimating a second travel time over the second link, also based at least in part on the data feed. The method assumes that a real-time data feed is not available for the second link, and thus estimates the traffic flow over the second link based on the known traffic flow over the first link and other known data, such as historical traffic patterns and physical parameters of the transportation network.
摘要:
A method for constructing an overlay multicast tree to deliver data from a source to an identified group of nodes is provided in which a plurality of nodes are identified and mapped into multidimensional Euclidean space. A geometric region is constructing having a size that is the minimum size necessary to contain the source and all the nodes. Once constructed, a tree is created beginning at the source and including all of the nodes within the geometric region.
摘要:
Methods and apparatus operating in a stream processing network perform load shedding and dynamic resource allocation so as to meet a pre-determined utility criterion. Load shedding is envisioned as an admission control problem encompassing source nodes admitting workflows into the stream processing network. A primal-dual approach is used to decompose the admission control and resource allocation problems. The admission control operates as a push-and-pull process with sources pushing workflows into the stream processing network and sinks pulling processed workflows from the network. A virtual queue is maintained at each node to account for both queue backlogs and credits from sinks. Nodes of the stream processing network maintain shadow prices for each of the workflows and share congestion information with neighbor nodes. At each node, resources are devoted to the workflow with the maximum product of downstream pressure and processing rate, where the downstream pressure is defined as the backlog difference between neighbor nodes. The primal-dual controller iteratively adjusts the admission rates and resource allocation using local congestion feedback. The iterative controlling procedure further uses an interior-point method to improve the speed of convergence towards optimal admission and allocation decisions.
摘要:
Techniques are provided for determining a capacity allocation in a multi-tiered computing system. In one aspect of the invention, a technique for designing capacity allocation for a multi-tiered computing system, each tier of the computing system having one or more computing devices (e.g., servers), comprises the following steps/operations. Input parameters relating to capacity allocation are obtained. A capacity allocation is computed based on at least a portion of the input parameters, the capacity allocation being computable such that one or more end-to-end performance measures are substantially satisfied for multiple service classes. The capacity allocation computation may minimize a cost function. The capacity allocation computation may also satisfy one or more mean delay guarantees for the multiple service classes, one or more tail distribution guarantees for the multiple service classes, or both one or more mean delay guarantees and one or more tail distribution guarantees for the multiple service classes.
摘要:
A method for constructing an overlay multicast tree to deliver data from a source to an identified group of nodes is provided in which a plurality of nodes are identified and mapped into multidimensional Euclidean space. A geometric region is constructing having a size that is the minimum size necessary to contain the source and all the nodes. Once constructed, a tree is created beginning at the source and including all of the nodes within the geometric region.