Marlon E. Pierce

SERVOGrid complexity computational environments (CCE) integrated performance analysis

In this paper we describe the architecture and initial performance analysis results of the SERVOGrid complexity computational environments (CCE). The CCE architecture is based on a lightly coupled, service oriented architecture approach that is suitable for distributed applications that are tolerant of Internet latencies. CCE focuses on integrating diverse Web and grid services for coupling scientific applications to geographical information systems. The services and coupling/orchestrating infrastructure are mapped to problems in geophysical data mining, pattern informatics, and multiscale geophysical simulation.

Management of real‐time streaming data Grid services

We discuss our message‐based approach to managing real‐time data streams and building higher level services to produce and consume them. Our messaging system acts as a substrate that can be used to provide qualities of service to various streaming applications ranging from audio–video collaboration systems to sensor Grids. The messaging substrates are composed of distributed, hierarchically arranged message broker networks. Services such as filters are deployed along the edges of the network. We discuss the role of management systems for both broker networks and filter services: broker network topologies must be created and maintained, and distributed filters must be arranged in appropriate sequences. These managed broker networks may be applied to a wide range of problems. We discuss applications to audio–video collaboration in some detail and also describe applications to streaming Global Positioning System data streams. These provide specific application filters that can transform and republish message streams to the broker system. Copyright

iSERVO: Implementing the International Solid Earth Research Virtual Observatory by Integrating Computational Grid and Geographical Information Web Services

We describe the goals and initial implementation of the International Solid Earth Virtual Observatory (iSERVO). This system is built using a Web Services approach to Grid computing infrastructure and is accessed via a component-based Web portal user interface. We describe our implementations of services used by this system, including Geographical Information System (GIS)-based data grid services for accessing remote data repositories and job management services for controlling multiple execution steps. iSERVO is an example of a larger trend to build globally scalable scientific computing infrastructures using the Service Oriented Architecture approach. Adoption of this approach raises a number of research challenges in millisecond-latency message systems suitable for internet-enabled scientific applications. We review our research in these areas.

Analysis of streaming GPS measurements of surface displacement through a web services environment

We present a method for performing mode classification of real-time streams of GPS surface position data. Our approach has two parts: an algorithm for robust, unconstrained fitting of hidden Markov models (HMMs) to continuous-valued time series, and SensorGrid technology that manages data streams through a series of filters coupled with a publish/subscribe messaging system. The SensorGrid framework enables strong connections between data sources, the HMM time series analysis software, and users. We demonstrate our approach through a Web portal environment through which users can easily access data from the SCIGN and SOPAC GPS networks in Southern California, apply the analysis method, and view results. Ongoing real-time mode classifications of streaming GPS data are displayed in a map-based visualization interface

Management of real-time streaming data grid services

We discuss the architectural and management support for real time data stream applications, both in terms of lower level messaging and higher level service, filter and session structures. In our approach, messaging systems act as a Grid substrate that can provide qualities of service to various streaming applications ranging from audio-video collaboration to sensor grids. The messaging substrate is composed of distributed, hierarchically arranged message brokers that form networks. We discuss approaches to managing systems for both broker networks and application filters: broker network topologies must be created and maintained, and distributed filters must be arranged in appropriate sequences. These managed broker networks may be applied to a wide range of problems. We discuss applications to audio/video collaboration in some detail and also describe applications to streaming Global Positioning System data streams.

Grids for real time data applications

We describe our work in building support for streaming data services for Geographical Information System Grid services. We examine how streaming approaches may be used to increase data service performance for transporting XML messages. Similarly, streaming versions of traditional static map services may be combined with general audio/video session management capabilities to build collaborative, annotatable shared maps. Distributed services linked through messaging substrates require information and broker management capabilities, and we describe our research here. Finally, we discuss efficient XML representation techniques that can be used to increase performance of Web Services and support Web enabled devices.

Messaging in web service grid with applications to geographical information systems

Several efforts to design globally distributed computing systems have converged to the principles of message-centric, service-oriented architectures. As realized through several Web Service specifications, these provide the scaling, robustness, and reliability for delivering distributed capabilities that collectively form virtual organizations. Service architectures are based a clean separation between service implementations and their communication patterns. In this article, we examine several consequences of this separation. First, services should exist on a general purpose, software messaging substrate. Services (and their containers) inherit various qualities of service directly from this substrate: we implement message level security, reliability, events, and notifications in the message routing middleware. Second, all communications involving services should be treated as messages. This applies not only to remote procedure call-style messages and notifications, but to streaming data as well. Finally, services are often domain-specific, but collective applications are cross-domain. Using message-based Geographical Information Systems as an example, we illustrate how a Grid of services is really a Grid of Grids: a composition of capabilities developed independently of specific end applications.

QuakeSim: Web Services, Portals, and Infrastructure for Geophysics

We discuss significant recent updates and revisions to the QuakeSim portal and Web services, which provide access to geophysical applications, data sets, and real time sensor data. These new developments include a) significant updates to the Web portal, b) a revision of Web services to better encapsulate applications, c) additional services for generating keyhole markup language markups of maps, and d) support for real-time GLOBAL POSITIONING Data.

Building Sensor Filter Grids: Information Architecture for the Data Deluge

We discuss a general architectural approach to knowledge and information management and delivery in distributed systems. Our approach is based on the recognition that time-stamped, streaming information message units form the core of seemingly disparate systems that range from online sensors and scientific instruments to Web information retrieval. Globally distributable grid services manage these information streams. Geographical information system services provide exemplary realizations of this picture and may be used as a model for other scientific domains. With this unified architecture in place, we may begin to consider the problems of information integration as equivalent to sensor federation.

Automating metadata web service deployment for problem solving environments

XML-based metadata information services are a crucial core service needed by Problem Solving Environments built over emerging service-based, globally-scaled distributed systems, as envisioned by the Open Grid Services Architecture and the Semantic Web. Developing user interfaces and services bindings for manipulating instances of particular schemas is thus extremely important and needs to be made as simple as possible. In this paper we describe procedures for automating the creation of Web Service environments that can be used to simplify the creation and deployment of schema-based metadata services.