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Title: STAR Online Framework: from Metadata Collection to Event Analysis and System Control

Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States). Relativistic Heavy Ion Collider (RHIC)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
OSTI Identifier:
Report Number(s):
R&D Project: PO 004; KB0202012
DOE Contract Number:
Resource Type:
Resource Relation:
Conference: 16th International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT2014); University of Praque; 20140901 through 20140905
Country of Publication:
United States

Citation Formats

Arkhipkin D., and STAR Collaboration. STAR Online Framework: from Metadata Collection to Event Analysis and System Control. United States: N. p., 2014. Web.
Arkhipkin D., & STAR Collaboration. STAR Online Framework: from Metadata Collection to Event Analysis and System Control. United States.
Arkhipkin D., and STAR Collaboration. Mon . "STAR Online Framework: from Metadata Collection to Event Analysis and System Control". United States. doi:.
title = {STAR Online Framework: from Metadata Collection to Event Analysis and System Control},
author = {Arkhipkin D. and STAR Collaboration},
abstractNote = {},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Sep 01 00:00:00 EDT 2014},
month = {Mon Sep 01 00:00:00 EDT 2014}

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  • We report our experience on migrating STARs Online Services (Run Control System, Data Acquisition System, Slow Control System and Subsystem Monitoring) from direct read/write database accesses to a modern non-blocking message-oriented infrastructure. Based on the Advanced Messaging Queuing Protocol (AMQP) and standards, this novel approach does not specify the message data structure, allowing great flexibility in its use. After careful consideration, we chose Google Protocol Buffers as our primary (de)serialization format for structured data exchange. This migration allows us to reduce the overall system complexity and greatly improve the reliability of the metadata collection and the performance of our onlinemore » services in general. We will present this new framework through its software architecture overview, providing details about our staged and non-disruptive migration process as well as details of the implementation of pluggable components to provide future improvements without compromising stability and availability of services.« less
  • Nobody is better suited to describe data than the scientist who created it. This description about a data is called Metadata. In general terms, Metadata represents the who, what, when, where, why and how of the dataset [1]. eXtensible Markup Language (XML) is the preferred output format for metadata, as it makes it portable and, more importantly, suitable for system discoverability. The newly developed ORNL Metadata Editor (OME) is a Web-based tool that allows users to create and maintain XML files containing key information, or metadata, about the research. Metadata include information about the specific projects, parameters, time periods, andmore » locations associated with the data. Such information helps put the research findings in context. In addition, the metadata produced using OME will allow other researchers to find these data via Metadata clearinghouses like Mercury [2][4]. OME is part of ORNL s Mercury software fleet [2][3]. It was jointly developed to support projects funded by the United States Geological Survey (USGS), U.S. Department of Energy (DOE), National Aeronautics and Space Administration (NASA) and National Oceanic and Atmospheric Administration (NOAA). OME s architecture provides a customizable interface to support project-specific requirements. Using this new architecture, the ORNL team developed OME instances for USGS s Core Science Analytics, Synthesis, and Libraries (CSAS&L), DOE s Next Generation Ecosystem Experiments (NGEE) and Atmospheric Radiation Measurement (ARM) Program, and the international Surface Ocean Carbon Dioxide ATlas (SOCAT). Researchers simply use the ORNL Metadata Editor to enter relevant metadata into a Web-based form. From the information on the form, the Metadata Editor can create an XML file on the server that the editor is installed or to the user s personal computer. Researchers can also use the ORNL Metadata Editor to modify existing XML metadata files. As an example, an NGEE Arctic scientist use OME to register their datasets to the NGEE data archive and allows the NGEE archive to publish these datasets via a data search portal ( These highly descriptive metadata created using OME allows the Archive to enable advanced data search options using keyword, geo-spatial, temporal and ontology filters. Similarly, ARM OME allows scientists or principal investigators (PIs) to submit their data products to the ARM data archive. How would OME help Big Data Centers like the Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC)? The ORNL DAAC is one of NASA s Earth Observing System Data and Information System (EOSDIS) data centers managed by the Earth Science Data and Information System (ESDIS) Project. The ORNL DAAC archives data produced by NASA's Terrestrial Ecology Program. The DAAC provides data and information relevant to biogeochemical dynamics, ecological data, and environmental processes, critical for understanding the dynamics relating to the biological, geological, and chemical components of the Earth's environment. Typically data produced, archived and analyzed is at a scale of multiple petabytes, which makes the discoverability of the data very challenging. Without proper metadata associated with the data, it is difficult to find the data you are looking for and equally difficult to use and understand the data. OME will allow data centers like the NGEE and ORNL DAAC to produce meaningful, high quality, standards-based, descriptive information about their data products in-turn helping with the data discoverability and interoperability. Useful Links: USGS OME: NGEE OME: ARM OME: Contact: Ranjeet Devarakonda ( References: [1] Federal Geographic Data Committee. Content standard for digital geospatial metadata. Federal Geographic Data Committee, 1998. [2] Devarakonda, Ranjeet, et al. "Mercury: reusable metadata management, data discovery and access system." Earth Science Informatics 3.1-2 (2010): 87-94. [3] Wilson, B. E., Palanisamy, G., Devarakonda, R., Rhyne, B. T., Lindsley, C., & Green, J. (2010). Mercury Toolset for Spatiotemporal Metadata. [4] Pouchard, L. C., Branstetter, M. L., Cook, R. B., Devarakonda, R., Green, J., Palanisamy, G., ... & Noy, N. F. (2013). A Linked Science investigation: enhancing climate change data discovery with semantic technologies. Earth science informatics, 6(3), 175-185.« less
  • The D0 experiment is one of the two High-Energy proton anti-proton collider experiments at Fermilab, USA. Since the detector serves multiple physics purposes, it consists of many different sub-detector systems together with supporting control systems. Therefore, online event monitoring plays a crucial role in ensuring detector performance and data quality by parasitically sampling events during the data taking. ROOT, a physics analysis package developed at CERN, is used in the D0 online monitoring as the main analysis tool, providing a graphical user interface that interacts remotely with an analysis executable and tools to monitor informative histograms as they get updatedmore » in shared memory throughout the data taking. In this paper, the authors present the basic structure of the D0 online monitoring system and the use of ROOT in the system.« less