Abstract: A cooperative data stream processing system is provided that utilizes a plurality of independent, autonomous and potentially heterogeneous sites in a cooperative arrangement to process user-defined inquiries over dynamic, continuous streams of data. The system derives jobs from the inquiries and these jobs are executed on the various distributed sites by executing applications containing processing elements on these sites. Therefore, components of a given job can be executed simultaneously and in parallel on a plurality of sites within in the system. The sites associated with a given job execution have the need to share data, both primal and derived. A tunnel mechanism is provided that establishes tunnels between pairs of sites within the system. Each tunnel includes either a sink processing element on an originating site and a source processing element on a destination site or a gateway processing element on each site and a network connection between the sink and source processing elements.

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 packet traceback in a network includes maintaining an identity number (ID) for each node in a network and generating a signature (e.g., a message authentication code (MAC)) using a secret key shared between each node on a forwarding path and a sink. Each forwarding node leaves a mark by appending its ID and a signature in the packet, either in a deterministic manner or with a probability. Upon receiving a packet at the sink, correctness of the signatures included in each packet is verified in the reverse order by which these signatures were appended. A last valid MAC is determined in the forwarding path to determine the locations of compromised nodes that collude in false data injection attacks.

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: Methods and systems are provided for identifying and allocating resources disposed within a plurality of distributed and autonomous computing systems, each of which may have its own legacy resource discovery service. Resource identification servers disposed within each one of the distributed computing systems communicate resource attribute data to a tree hierarchy of dedicated servers. The resource attribute data are maintained in native formats within the distributed computing systems and are mapped to a common format provided by the dedicated servers. The resource attribute data are aggregated at each node within the tree hierarchy, communicated up through the tree hierarchy to one or more root nodes and replicated down through all of the nodes. Additional system robustness is provided through period resource checks and resource attribute data updates. Resource allocation queries are submitted to any level node within the hierarchy and forwarded to the proper computing system for processing.