Abstract: A failure recovery framework to be used in cooperative data stream processing is provided that can be used in a large-scale stream data analysis environment. Failure recovery supports a plurality of independent distributed sites, each having its own local administration and goals. The distributed sites cooperate in an inter-site back-up mechanism to provide for system recovery from a variety of failures within the system. Failure recovery is both automatic and timely through cooperation among sites. Back-up sites associated with a given primary site are identified. These sites are used to identify failures within the primary site including failures of applications running on the nodes of the primary site. The failed applications are reinstated on one or more nodes within the back-up sites using job management instances local to the back-up sites in combination with previously stored state information and data values for the failed applications.

Abstract: Methods and systems are provided for optimally trading off replication overhead and consistency levels in distributed data replication where nodes are organized in a hierarchy. The root node has the original data that need to be replicated at all other nodes, and the replicated copies have a freshness threshold that must be satisfied. The data are propagated through periodic updates in the hierarchy. Each node periodically sends data to its child nodes. Given the freshness threshold, an algorithm and its distributed protocol can determine the optimal update period for each link of the hierarchy such that the freshness threshold is satisfied for every node and the overall replication overhead is minimized. The systems and methods can be used in any scenario where replicated data have consistency requirements, such as in a replicate overlay assisted resource discovery system.

Abstract: 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.

Abstract: Apparatus and methods for identifying traffic patterns to web sites based on templates that characterize the arrival of traffic to the web sites are provided. Based on these templates, determinations are made as to which web sites should be co-located so as to optimize resource allocation. Specifically, web sites whose templates are complimentary, i.e. a first web site having a peak in arrival traffic at time t1 and a second web site that has a trough in arrival traffic at time t1, are designated as being candidates for co-location. In addition, the present invention uses the templates identified for the traffic patterns of web sites to determine thresholds for offloading traffic to other servers. These thresholds include a first threshold at which offloading should be performed, a second threshold that takes into consideration the lead time needed to begin offloading, and a third threshold that takes into consideration a lag time needed to stop all offloading of traffic to the other servers.

Abstract: Apparatus and methods for identifying traffic patterns to web sites based on templates that characterize the arrival of traffic to the web sites are provided. Based on these templates, determinations are made as to which web sites should be co-located so as to optimize resource allocation. Specifically, web sites whose templates are complimentary, i.e. a first web site having a peak in arrival traffic at time t1 and a second web site that has a trough in arrival traffic at time t1, are designated as being candidates for co-location. In addition, the present invention uses the templates identified for the traffic patterns of web sites to determine thresholds for offloading traffic to other servers. These thresholds include a first threshold at which offloading should be performed, a second threshold that takes into consideration the lead time needed to begin offloading, and a third threshold that takes into consideration a lag time needed to stop all offloading of traffic to the other servers.

Abstract: Methods and system for dynamic reallocation of data processing resources for efficient processing of sensor data in a distributed network is provided. The methods and system include determining a data transmission cost ft; determining a data processing cost fp; determining a data storage cost fs; and determining a data query Q which minimizes f(ft+fp+fs) for a system of networked data processing resources.

Abstract: Methods and systems are provided for optimally trading off replication overhead and consistency levels in distributed data replication where nodes are organized in a hierarchy. The root node has the original data that need to be replicated at all other nodes, and the replicated copies have a freshness threshold that must be satisfied. The data are propagated through periodic updates in the hierarchy. Each node periodically sends data to its child nodes. Given the freshness threshold, an algorithm and its distributed protocol can determine the optimal update period for each link of the hierarchy such that the freshness threshold is satisfied for every node and the overall replication overhead is minimized. The systems and methods can be used in any scenario where replicated data have consistency requirements, such as in a replicate overlay assisted resource discovery system.

Abstract: 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.

Abstract: In one embodiment, the present invention is a method and apparatus for automatic system parameter configuration for performance improvement. One embodiment of the inventive method involves formulating a black box optimization problem, and solving the optimization problem using an enhanced smart hill climbing method. The smart hill climbing method includes both a global and a more precise local search to identify an optimal solution.

Abstract: Method for modeling the performance of an Information Technology system are disclosed. The method includes the steps of receiving performance data of the system; receiving data of transaction flows and system topology; and inferring service demand parameters based on the received data. If closed form expressions are available to characterize the system, an optimization algorithm based on minimum distance between predicted and measured response times and may be used to obtain the performance parameters. Alternatively, a discrete event simulator together with a set of meta-heuristic search methods may be applied to obtain the optimized performance parameters.

Abstract: Arrangements and methods for developing a software toolkit that can be used to design or obtain parameters for a sensor network. High-level guidelines on the basic relations between sensor network parameters like number of sensors, degree of quantization at each sensor, and the distortion requirements, based on a deep analysis on two basic coding possibilities (multiplexed point-to-point, distributed) are contemplated. By evaluating tradeoffs among the various parameters, an optimization framework to obtain the most cost-effective design with required quantization capabilities pertaining to given distortion criterion is provided.

Abstract: In one embodiment, the present invention is a method and apparatus for automatic system parameter configuration for performance improvement. One embodiment of the inventive method involves formulating a black box optimization problem, and solving the optimization problem using an enhanced smart hill climbing method. The smart hill climbing method includes both a global and a more precise local search to identify an optimal solution.

Abstract: A system and method for performance modeling for an information technology (IT) system having a server(s) for performing a number of types of transactions includes receiving data for system topology and transaction flows and receiving performance measurement data for the IT system. The measurement data is clustered into multiple regimes based on similarities. Service demand and network delay parameters may be inferred based on clustered data.

Abstract: Several algorithms are provided to estimate and remove relative clock skews from delay measurements based on the computation of convex hulls. The algorithms are linear in the number of measurement points for the case with no clock resets. For the more challenging case with clock resets, i.e., the clocks are reset to some reference times during the measurement period, linear algorithms are provided to identify the clock resets and derive the best clock skew lines. The algorithms are also extended to environments in which at least one of the clocks is controlled by Network Time Protocol. These algorithms can also be extended for active clock synchronization to replace or further improve Network Time Protocol.

Abstract: 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.

Abstract: The invention is a method and apparatus for on-demand resource planning for unified messaging services. In one embodiment, multiple clients are served by a single system, and existing system resources are allocated among all clients in a manner that optimizes system output and service provider profit without the need to increase system resources. In one embodiment, resource allocation and job scheduling are guided by individual service level agreements between the service provider and the clients that dictate minimum service levels that must be achieved by the system. Jobs are processed in a manner that at least meets the specified service levels, and the benefit or profit derived by the service provider is maximized by prioritizing incoming job requests within the parameters of the specified service levels while meeting the specified service levels. Thus, operation and hardware costs remain substantially unchanged, while system output and profit are maximized.

Abstract: Method for modeling the performance of an Information Technology system are disclosed. The method includes the steps of receiving performance data of the system; receiving data of transaction flows and system topology; and inferring service demand parameters based on the received data. If closed form expressions are available to characterize the system, an optimization algorithm based on minimum distance between predicted and measured response times and may be used to obtain the performance parameters. Alternatively, a discrete event simulator together with a set of meta-heuristic search methods may be applied to obtain the optimized performance parameters.

Abstract: Apparatus and methods for identifying traffic patterns to web sites based on templates that characterize the arrival of traffic to the web sites are provided. Based on these templates, determinations are made as to which web sites should be co-located so as to optimize resource allocation. Specifically, web sites whose templates are complimentary, i.e. a first web site having a peak in arrival traffic at time t1 and a second web site that has a trough in arrival traffic at time t1, are designated as being candidates for co-location. In addition, the present invention uses the templates identified for the traffic patterns of web sites to determine thresholds for offloading traffic to other servers. These thresholds include a first threshold at which offloading should be performed, a second threshold that takes into consideration the lead time needed to begin offloading, and a third threshold that takes into consideration a lag time needed to stop all offloading of traffic to the other servers.

Abstract: Apparatus and methods for classifying web sites are provided. With the apparatus and methods, traffic data is obtained for a plurality of web sites. This patterns, or templates, for each web site are generated based on this traffic data and the patterns are clustered into classes of web sites using a clustering algorithm. The clusters, or classes, are then profiled to generate a template for each class. The template for each class is generated by first shifting the patterns for each web site that is part of the class to compensate for effects like time zone differences, if any, and then identifying a pattern that is most similar to all of the patterns in the class. Once the template for each class is generated, this template is then used with traffic data from a new web site to classify the new web site into one of the existing classes.

Abstract: Several algorithms are provided to estimate and remove relative clock skews from delay measurements based on the computation of convex hulls. The algorithms are linear in the number of measurement points for the case with no clock resets. For the more challenging case with clock resets, i.e., the clocks are reset to some reference times during the measurement period, linear algorithms are provided to identify the clock resets and derive the best clock skew lines. The algorithms are also extended to environments in which at least one of the clocks is controlled by Network Time Protocol. These algorithms can also be extended for active clock synchronization to replace or further improve Network Time Protocol.