Abstract: Methods, systems, and computer program products for determining performance dynamics are provided herein.

Abstract: Methods and arrangements for localizing faults in programs. A program is assimilated, the program comprising statements. Output behavior of the statements is modeled, and statement occurrences are annotated. Passing and failing spectra are differenced to yield a difference, and a fault is located via employing the difference.

Abstract: A method and system to transform a plurality of programs associated with a plurality of programming languages is provided. In the method, a request is received by a computer to transform a first program in a first programming language to a second program in a second programming language. The first program is then transformed, wherein the transformation includes eliminating errors using predefined criteria. Further, the method maps a statement of the first program with a corresponding statement of the second program.

Abstract: Systems and methods execute a computer program to produce a trace of the computer program and divide the trace into independent threads of execution. Each of the independent threads of execution comprises an execution sequence of the lines of programming code that ends with an identified write line of programming code that outputs an incorrect result. These systems and methods also identify key field within each of the independent threads of execution. In programming, which is processing records in a table one by one, key-fields are a subset of the fields of the table. The key fields impact the computations sequence leading up to the identified write line of the programming code. These systems and methods identify key-based dynamic slices from the independent threads of execution. Each of the key-based dynamic slices includes lines of programming code that are used in computations, processing the table records corresponding to the key fields.

Abstract: A method and system to transform a plurality of programs associated with a plurality of programming languages is provided. In the method, a request is received by a computer to transform a first program in a first programming language to a second program in a second programming language. The first program is then transformed, wherein the transformation includes eliminating errors using predefined criteria. Further, the method maps a statement of the first program with a corresponding statement of the second program.

Abstract: Methods and arrangements for localizing faults in programs. A program is assimilated, the program comprising statements. Output behavior of the statements is modeled, and statement occurrences are annotated. Passing and failing spectra are differenced to yield a difference, and a fault is located via employing the difference.

Abstract: Systems and methods execute a computer program to produce a trace of the computer program and divide the trace into independent threads of execution. Each of the independent threads of execution comprises an execution sequence of the lines of programming code that ends with an identified write line of programming code that outputs an incorrect result. These systems and methods also identify key field within each of the independent threads of execution. In programming, which is processing records in a table one by one, key-fields are a subset of the fields of the table. The key fields impact the computations sequence leading up to the identified write line of the programming code. These systems and methods identify key-based dynamic slices from the independent threads of execution. Each of the key-based dynamic slices includes lines of programming code that are used in computations, processing the table records corresponding to the key fields.

Abstract: Disclosed are methods, apparatus and computer programs for improving performance and resource utilization of cluster-based data processing systems. The number of persistent connections between first and second data processing units of a system is adjusted according to monitored performance of communications between the nodes. The monitored performance measure is the queuing delay between the nodes, and the number of connections is increased and decreased as changing load conditions increase and decrease the queuing delay. A method of establishing and closing persistent connections in response to a monitored queuing delay between a front-end gateway computer and each of a cluster of back-end servers is used to improve the performance of a cluster-based Web server or provision of Web services. Unwanted connections are closed to enable system resources to be allocated to other processes.

Abstract: Decentralized orchestration of composite services results in a number of flow topologies which differ in their messaging patterns and the distribution of flow code amongst different partitions of a topology. Different performance metrics result for different topologies, and this is governed by the availability of resources, such as CPU cycles, memory, network bandwidth, and so on. A performance model is used to evaluate the performance of different topologies based on availability of resources, and dynamically direct client requests between different topologies according to prevailing conditions.

Abstract: Disclosed are methods, apparatus and computer programs for improving performance and resource utilization of cluster-based data processing systems. The number of persistent connections between first and second data processing units of a system is adjusted according to monitored performance of communications between the nodes. The monitored performance measure is the queuing delay between the nodes, and the number of connections is increased and decreased as changing load conditions increase and decrease the queuing delay. A method of establishing and closing persistent connections in response to a monitored queuing delay between a front-end gateway computer and each of a cluster of back-end servers is used to improve the performance of a cluster-based Web server or provision of Web services. Unwanted connections are closed to enable system resources to be allocated to other processes.

Abstract: Disclosed are methods, apparatus and computer programs for improving performance and resource utilization of cluster-based data processing systems. The number of persistent connections between first and second data processing units of a system is adjusted according to monitored performance of communications between the nodes. The monitored performance measure is the queuing delay between the nodes, and the number of connections is increased and decreased as changing load conditions increase and decrease the queuing delay. A method of establishing and closing persistent connections in response to a monitored queuing-delay between a front-end gateway computer and each of a cluster of back-end servers is used to improve the performance of a cluster-based Web server or provision of Web services. Unwanted connections are closed to enable system resources to be allocated to other processes.

Abstract: A performance management system and method for cluster-based web services comprising a gateway for receiving a user request, assigning the user request to a class, queuing the user request based on said class, and dispatching the user request to one of a plurality of server resources based on the assigned class and control parameters. The control parameters are continuously updated by a global resource manager which tracks and evaluates system performance.