Julie Waterhouse

Runtime Monitoring of Web Service Conversations

For a system of distributed processes, correctness can be ensured by (statically) checking whether their composition satisfies properties of interest. However, Web services are distributed processes that dynamically discover properties of other Web services. Since the overall system may not be available statically and since each business process is supposed to be relatively simple, we propose to use runtime monitoring of conversations between partners as a means of checking behavioral correctness of the entire Web service system. Specifically, we identify a subset of UML 2.0 sequence diagrams as a property specification language and show that it is sufficiently expressive for capturing safety and liveness properties. By transforming these diagrams to automata, we enable conformance checking of finite execution traces against the specification. We show how our language can be used to specify the specification property system (SPS). We describe an implementation of our approach as part of an industrial system. Finally, we discuss our experience of specifying and monitoring a number of properties from three existing applications.

Runtime monitoring of web service conversations

For a system of distributed processes, correctness can be ensured by (statically) checking whether their composition satisfies properties of interest. In contrast, Web services are being designed so that each partner discovers properties of others dynamically, through a published interface. Since the overall system may not be available statically and since each business process is supposed to be relatively simple, we propose to use runtime monitoring of conversations between partners as a means of checking behavioural correctness of the entire web service system. Specifically, we identify a subset of UML 2.0 Sequence Diagrams as a property specification language and show that it is sufficiently expressive for capturing safety and liveness properties. By transforming these diagrams to automata, we enable conformance checking of finite execution traces against the specification. We describe an implementation of our approach as part of an industrial system and report on preliminary experience.

Modeling the Information Behaviour of Software Engineers Using a Work-Task Framework

Faced with the rapid proliferation of digital information resources within organizations, employees need targeted search systems in order to be effective in their jobs. The goal of this study is to develop a model of information behaviour within a work-task framework that can be used to inform the design of a workplace information search system. In a two-phase process, we conducted a series of studies using multiple methods to identify workplace characteristics and to understand how they influence the needs, search strategies, and information sources used by software engineers working as services consultants in a large high-tech company.

SLA-driven business process management in SOA

The management of non-functional goals, or Service Level Agreements (SLA), in the development of business processes in a Service Oriented Architecture (SOA) often requires much manual and error-prone effort by all parties throughout the entire lifecycle of the processes. The formal specification of SLAs into development tools can simplify some of this effort. In particular, the runtime provisioning and monitoring of processes can be achieved by an autonomic system that adapts to changing conditions to maintain the SLAs goals. SOA supports partitioning a system into services that are running in a distributed execution environment. When coupled with an associated cost model, a process can be both executed and monitored in an optimal manner, based on a declarative, user-specified optimality function.

Runtime estimation using the case-based reasoning approach for scheduling in a grid environment

Grid scheduling performance is significantly affected by the accuracy of job runtime estimation. Since past performance is a good indicator of future trends, we use a case-based reasoning approach to predict the execution time, or run time, based on past experience. We first define the similarity of jobs and similarity of machines, and then determine which job and machine characteristics affect the run time the most by analyzing information from previous runs. We then create a case base to store historical data, and use the TA3 case-based reasoning system to fetch all relevant cases from the case base. We apply this approach to schedule Functional Regression Tests for IBM® DB2® Universal DatabaseTM (DB2 UDB) products. The results show that our approach achieves low runtime estimation errors and substantially improves grid scheduling performance.

A focused learning environment for Eclipse

The support available in Eclipse to help software developers learn complex APIs and development tools is inadequate; the support is largely passive and the support typically operates alongside the resources associated with normal software development tasks, thereby overloading the environment with additional complexity. In this paper, we describe an approach that enables a dynamic learning process within the context of a developers Eclipse work environment. Our approach integrates a mechanism for explicit support of a learning process flow (cheat sheets) with a mechanism for explicit representation of different work contexts (Mylar). We have implemented a working prototype of our approach. We found it relatively easy to integrate cheat sheets with Mylar through available extension points. We describe our architecture and report on some limitations and missing features in the existing plug-ins we discovered as we developed our prototype.

CasSim: a top-level-simulator for grid scheduling and applications

Effective and efficient use of grid resources is achieved by using scheduling heuristics. Many such heuristics have been developed over the last decade. However, as none of the heuristics performs well in all conditions, how can we dynamically determine the best one to choose? In this paper, we describe CasSim (Centre for Advanced Studies Simulator), and use it to dynamically select the best heuristic. In contrast to other grid simulators, CasSim has a simple abstract model, and can easily and quickly compare different scheduling heuristics. Experimental validation of CasSim shows that CasSim selects heuristics accurately and it can be used in the real system. In addition, we extend CasSim to support a wider range of applications by enabling users to define costs.

Modeling and implementing a business process using WebSphere Lombardi Edition 7.1

Business process management (BPM) helps companies to simplify, transform, and automate their processes, and to better integrate them with technology. As a result, the processes become more predictable, flexible, and cost-efficient. In turn, the business itself becomes more efficient and effective in communication and decision-making. It is able to reduce costs, to innovate, to react more quickly to change, and to increase its return on investment.