Grid Computing: A Vision for LTER Cyberinfrastructure

By Mark Servilla, LTER Office, University of New Mexico

Landscape acoustic sensing has been a passion of Dr. Stuart Gage for the past five years. As a University Distinguished Professor at Michigan State University and one of the principle investigators at the Kellogg Biological Station LTER site, one of Dr. Gage's dreams is to seamlessly integrate all of the sensors under his management into a single virtual system that collects, stores, and analyzes the voluminous acoustic data that is recorded every 30 minutes. Recently, Dr. Gage participated in the LTER Grid Pilot Study a demonstration of grid technology that created a web-based environment for the analysis of his acoustic data.

In response to the LTER Network Information System Strategic Plan, the LTER Grid Pilot Study investigated grid middleware and high-performance computer applications in its mission to "facilitate and promote advances in collaborative and synthetic ecological science at multiple temporal and spatial scales." The LTER Grid Pilot Study was supported by the National Center for Supercomputer Applications (NCSA), a partner in the National Science Foundation GRIDS Center, and the LTER Network Office (LNO). The Pilot Study began in March, 2005 and concluded by demonstrating a functional application, the "Biophony Grid Portal", to the LTER Coordinating Committee meeting in Cape Charles, Virginia on September 20, 2005. To access the Biophony Grid Portal, a researcher must first authenticate to the system via a secure one-time log-on process that verifies their user name and password with the LTER LDAP registry. Once logged on, a researcher can select an acoustic signature from a dataset of known sounds (e.g., chipping sparrow) and determine if the species is present in a selected time series of acoustics contained in a digital library. The application computes the probability of match between the signature and each unknown sound in the library, along with an option to generate a sonogram (Figure 1), sound profile, power spectrum, and frequency histogram of the acoustic samples in the selected time series.

Figure 1. Sonogram of acoustic data identified as a Chipping Sparrow.

From a cyberinfrastructure perspective, the LTER Grid Pilot Study utilized standard middleware components of the Globus Toolkit and other grid software to enforce secure authentication and transactions for remote job submission, file transfer, and data analysis. In addition, all transactions within the system were logged into a relational database for use in audit and data provenance reporting. By using standard middleware components, interoperability between internal resources of the LTER Network Information System and external resources located within other networks, such as the Science Environment for Ecological Knowledge's "EcoGrid" project or the National Ecological Observatory Network (NEON), are ensured.

The success of the LTER Grid Pilot Study fully demonstrates the efficacy of grid middleware in support of LTER science to the LTER research community as exemplified by the Biophony Grid Portal application. It also identifies middleware components that could meet the requirements of a production version of an LTER Grid; such insight would have been difficult to grasp without a hands-on evaluation of the technology. Through this pilot study, a vision for a grid computing infrastructure (Figure 2) is an important component of the future of the LTER Network Information System necessary to meet the goal of Network-level synthetic science. "The issue of scaling has emerged as a significant issue, and grid technologies are an important approach to solving large scale data and analytical requirements." Dr. Stuart Gage.

SC'05 participants can see the Biophony Grid Portal in action at the NCSA booth on Tuesday, November 15 at 11:00 AM.

— Mark Servilla is the lead scientist for the LTER Network Information System.