Very large scientific datasets are increasingly becoming available in XML formats. At the same time, multi-core processing is increasingly becoming available on desktop- and laptop-class computing machines. Unfortunately, most XML parsers are still using algorithms that are inherently serial, which show little improvement on newer computing hardware. The current XML implementation landscape does not adequately meet the performance requirements of large scale applications. Thus far, applications using Web services (in the grid community, for example) have largely focused on XML protocol standardization and tool building efforts, and not on addressing the performance bottlenecks when dealing with large volumes of XML data. Generic parallel parsing has been studied in depth over the past thirty years. However, as yet, these results have not been applied to the problem of XML parsing. XML documents have some structural properties that make it more amenable to parallelized parsing than general context-free languages. As has been previously shown, XML parsers spend a large percentage of time tokenizing the input in aninherently serial process, typically running a deterministic finite automaton on the input. Our initial approach, described here, separates the process of parsing the XML from the process of reading the input. We take a well-known high performance parser, Piccolo, and apply two different strategies, Runahead and Piped, and examine the timing of the file read time and hence the overall time to parse large scientific XML files. Under the conditions tested here, performance decreases.

Note: OCR errors may be found in this Reference List extracted from the full text article. ACM has opted to expose the complete List rather than only correct and linked references.

	1	Alfred V. Aho , Jeffrey D. Ullman, The theory of parsing, translation, and compiling, Prentice-Hall, Inc., Upper Saddle River, NJ, 1972
	2	Bison -- GNU parser generator. Bison is a general-purpose parser generator that converts an annotated context-free grammar into an LALR(1) or GLR parser for that grammar, 2006. http://www.gnu.org/software/bison/.
	3	Jacques Cohen , Timothy Hickey , Joel Katcoff, Upper Bounds for Speedup in Parallel Parsing, Journal of the ACM (JACM), v.29 n.2, p.408-428, April 1982  [doi>10.1145/322307.322316]
	4	eBay. eBay Developers Program. http://developer.ebay.com/developercenter/soap/.
	5	Flex (The Fast Lexical Analyzer). Flex is a tool for generating scanners, 2006. http://flex.sourceforge.net/.
	6	On Building Parallel & Grid Applications: Component Technology and Distributed Services, Proceedings of the Second International Workshop on Challenges of Large Applications in Distributed Environments, p.44, June 07-07, 2004
	7	T. Gross , A. Sobel , M. Zolg, Parallel compilation for a parallel machine, Proceedings of the ACM SIGPLAN 1989 Conference on Programming language design and implementation, p.91-100, June 19-23, 1989, Portland, Oregon, United States
	8	Michael R. Head , Madhusudhan Govindaraju , Aleksander Slominski , Pu Liu , Nayef Abu-Ghazaleh , Robert van Engelen , Kenneth Chiu , Michael J. Lewis, A Benchmark Suite for SOAP-based Communication in Grid Web Services, Proceedings of the 2005 ACM/IEEE conference on Supercomputing, p.19, November 12-18, 2005  [doi>10.1109/SC.2005.2]
	9	Michael R. Head , Madhusudhan Govindaraju , Robert van Engelen , Wei Zhang, Benchmarking XML processors for applications in grid web services, Proceedings of the 2006 ACM/IEEE conference on Supercomputing, November 11-17, 2006, Tampa, Florida  [doi>10.1145/1188455.1188581]
	10	Howard P. Katseff, Using data partitioning to implement a parallel assembler, Proceedings of the ACM/SIGPLAN conference on Parallel programming: experience with applications, languages and systems, p.66-76, July 19-21, 1988, New Haven, Connecticut, United States
	11	W. Lu, K. Chiu, and Y. Pan. A Parallel Approach to XML Parsing. In 7th IEEE/ACM International Conference on Grid Computing (Grid 2006), pages 223--230, 2006.
	12	Yinfei Pan , Wei Lu , Ying Zhang , Kenneth Chiu, A Static Load-Balancing Scheme for Parallel XML Parsing on Multicore CPUs, Proceedings of the Seventh IEEE International Symposium on Cluster Computing and the Grid, p.351-362, May 14-17, 2007  [doi>10.1109/CCGRID.2007.14]
	13	Piccolo XML Parser for Java. Piccolo is a small, extremely fast XML parser for Java, 2006. http://piccolo.sourceforge.net/.
	14	Protein Sequence Database. Integrated collection of functionally annotated protein sequences. http://www.cs.washington.edu/research/projects/xmltk/xmldata/data/pir/psd7003.xml, 2001.
	15	R Development Core Team. R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria, 2007.
	16	Gurmeet Singh , Shishir Bharathi , Ann Chervenak , Ewa Deelman , Carl Kesselman , Mary Manohar , Sonal Patil , Laura Pearlman, A Metadata Catalog Service for Data Intensive Applications, Proceedings of the 2003 ACM/IEEE conference on Supercomputing, p.33, November 15-21, 2003
	17	Wei Zhang , Robert van Engelen, A Table-Driven Streaming XML Parsing Methodology for High-Performance Web Services, Proceedings of the IEEE International Conference on Web Services (ICWS'06), p.197-204, September 18-22, 2006  [doi>10.1109/ICWS.2006.15]