1 / 9

Using XML as the Foundation for a Network Resource Description Language

This article explores the use of XML as a standard, text-based representation for network data, including integrating tools and enhancing interfaces. It also discusses the concept of a grid standard for network data.

wilona
Download Presentation

Using XML as the Foundation for a Network Resource Description Language

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Using XML as the Foundation for a NetworkResource Description Language Peter A. Dinda

  2. Motivation • Network Resource Interface for external tools • A standard, text-based representation for network data • Integrating our own tools such as RPS • Integrating other tools such as NWS • Enhancing existing text-based interfaces • Potentially proposing a Grid standard Network data is structured data

  3. XML in a Nutshell #1 • Standard for presenting structured information via tag-based markup • Like HTML, except user gets to define the tags and their grammar • “DTD” or “Schema” (can be part of doc) • Unlike HTML, “well-formed” XML is always a tree, so it’s easy to parse • Tags can be anything but must nest • Unlike HTML, no styles or links are defined • They are DTDs! XSL, Xlink, Xpointer, blah blah • Self-defining text-based structured data format

  4. XML in a Nutshell #2 • “Well-formed” XML • It can be produced by the XML grammar • “Valid” XML • Well-formed and the document can be produced by your grammar (ie, the DTD) • Free XML parsers usually don’t “validate” • Probably not much of an issue for resource data • http://www.xml.com http://www.w3.org/XML/

  5. XML Tools • Free parsers available for C, Java, Perl, Python • Lots of commercial stuff • Microsoft (IE4, IE5, XML Notepad, lots of others) • Most parsers/tools don’t support the DOM interface and so are not interchangeable

  6. DTD/Schema Standardization • XSL (styles), Xlink/Xpointer (links), ... • DTDs being developed for very specific kinds of information • News stories • http://www.xmlnews.org/dtds/xmlnews-story.dtd • We could propose DTDs to the Grid Forum so that tools could exchange information

  7. Proof of Concept • Wrote XML serialization for RPS’s LoadMeasurement objects • Used Expat, a free (non-validating) XML parser written in C

  8. An XML Serialized LoadMeasurement <?xml version="1.0"?> <!DOCTYPE HostLoadList [ <!ELEMENT HostLoadList (HostLoadInfo)+> <!ELEMENT HostLoadInfo (Hostname, Period, SmoothingType, TimeStamp, Averages)> <!ELEMENT Period (#PCDATA)> <!ELEMENT SmoothingType (unix|mach)> <!ELEMENT TimeStamp (#PCDATA)> <!ELEMENT Averages (Average+)> <!ELEMENT Average (#PCDATA)> <!ATTLIST Average Number CDATA "0"> ]> <HostLoadList> <HostLoadInfo> <Hostname>pyramid.cmcl.cs.cmu.edu</Hostname> <Period>1000000</Period> <SmoothingType>1</SmoothingType> <TimeStamp>935508266.313773</TimeStamp> <Averages> <Average Number="-1">0.300000</Average> <Average Number="0">0.200000</Average> <Average Number="1">0.100000</Average> <Average Number="2">0.050000</Average> </Averages> </HostLoadInfo> </HostLoadList> DTD - the grammar for the HostLoadList document that follows Document - the serialized LoadMeasurement object

  9. Effort/Efficiency

More Related