SOAP-Based Metadata

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					A SOAP Based Metadata Service -
       IWICOS Broker

          Jyrki Haajanen & Robin Berglund
                    EOGEO 2001,
                   June 26th - 28th,
             Fredericton, New Brunswick,
                        Canada

                                      EOGEO 2001, June 26th - 28th,
                                      Fredericton, New Brunswick, Canada
INFORMATION TECHNOLOGY
Overview
 – IWICOS Project

 – Overall Architecture

 – SOAP Overview

 – The Broker & Use of SOAP

 – SOAP Evaluation

 – Conclusions
 Jyrki Haajanen                           EOGEO 2001, June 26th - 28th,
                                          Fredericton, New Brunswick, Canada   2
 INFORMATION TECHNOLOGY   IWICOS Broker
The IWICOS Project
•   Integrated weather, sea ice and ocean service system
•   Funded by the European Commission's IST programme
•   Duration 1.1.2000 - 31.12.2002
•   Goals
     – To research, evaluate and demonstrate technologies and approaches for
       cross-organisational interoperable met, ice, ocean GIS-service for seafarers
     – Demonstration will take two phases: base-line system and extended system
• Project status
     – The base-line system demonstration is performed in summer 2001




     Jyrki Haajanen                                          EOGEO 2001, June 26th - 28th,
                                                             Fredericton, New Brunswick, Canada   3
     INFORMATION TECHNOLOGY         IWICOS Broker
                  IWICOS Project Consortium
                                  Icelandic
                       Meteorological Office



                                                                      Technical Research
Nansen Environmental                                                    Centre of Finland
    Research Centre
                                                                        Finnish Institute of
                                                                         Marine Research




                                                                     Danish
                                                     Meteorological Institute

                                                                    Danish
                                                        Technical University




Jyrki Haajanen                                                       EOGEO 2001, June 26th - 28th,
                                                                     Fredericton, New Brunswick, Canada   4
INFORMATION TECHNOLOGY               IWICOS Broker
  IWICOS Architecture - Overview
  Overview
                                    End-User Systems
                       Broker
Producer                                                Client
                                         Facade
 Server                                                Software




Producer                                                Client
                                         Facade
 Server                                                Software


    flow of metadata
    flow of data




       Jyrki Haajanen                              EOGEO 2001, June 26th - 28th,
                                                   Fredericton, New Brunswick, Canada   5
       INFORMATION TECHNOLOGY   IWICOS Broker
   IWICOS Architecture - Metadata
                                  <?xml version="1.0" encoding="UTF-8"?>
A project specific XML format,    <Product xmlns:xsi="http://www.w3.org/2000/10/XMLSchema-instance" Category="SeaIce"
                                      ProductType="Analysis" HeaderVersion="1.0" AccessConstraints="Restricted Use">
   contains:                          <Extent>
• Spatial information                     <UL SpatialID="1" Lon="-49 30 02.35" Lat="61 56 45.95"/>
                                          <UR SpatialID="2" Lon="-39 20 38.61" Lat="63 06 07.36"/>
• Temporal information                    <LR SpatialID="3" Lon="-38 03 07.28" Lat="58 16 51.88"/>
                                          <LL SpatialID="4" Lon="-47 00 55.43" Lat="57 29 35.57"/>
• Processing information              </Extent>
                                      <ReferenceTime>
• Data format (GRIB, BSQ,                 <Instant Time="2001-04-27T09:20:00.000"/>
                                      </ReferenceTime>
   Shapefile, XML)                    <ValidTime>
                                          <Instant Time="2001-04-27T09:20:00.000"/>
• Projection information              </ValidTime>
                                      <ScheduledTime NextProduct="2001-04-28T09:12:00.000"
                                          Comment="Planned: 2001-04-28T09:17:00.000; 2001-04-29T09:12:00.000"/>
                                      <ProcessInfo Generator="DMI Ice Chart Analyst"
Minimal searchable set (MSS)              ProducerLocator="Some URI/URL"/>
• Selected subset of attributes       <Data Availability="true" FileLocator=" Some URI/URL/20010427092000IA.zip"
                                          FileSizeInBytes="144000" Compression="zip">
• Some additional attributes              <Shapefile>
                                              <ParameterEntry Parameter="IceConcentration" Units="tenths" Shape="polygon"/>
                                              <ParameterEntry Parameter="IceType" Units="class" Shape="polygon"/>
                                          </Shapefile>
                                      </Data>
                                      <Projection Datum="WGS-84" Spheroid="WGS-84">
                                          <ProjectionLambertConformalConic UnitsPlanar="meter">
                                              <ParametersLCC LatStdP1="66" LatStdP2="76" LonCtrMer="-39" LatOrg="55"
                                                   FalseE="1500000" FalseN="0"/>
                                          </ProjectionLambertConformalConic>
                                      </Projection>
                                  </Product>


        Jyrki Haajanen                                                           EOGEO 2001, June 26th - 28th,
                                                                                 Fredericton, New Brunswick, Canada   6
        INFORMATION TECHNOLOGY              IWICOS Broker
IWICOS Architecture - Producer Server
    Producer Server
                           Notifications of:
                            new data
                                                                            B
        Production
         Process
                            outdated data                                  r
                                                                            o
                            Data             Metadata
                                                                            k
                                                                            e
                     Web Server
                                                                            r


  Jyrki Haajanen                                   EOGEO 2001, June 26th - 28th,
                                                   Fredericton, New Brunswick, Canada   7
  INFORMATION TECHNOLOGY     IWICOS Broker
IWICOS Architecture - Broker
• Tasks:
   – Receive notification of new data and
       » Collect the metadata from the producer server (web server)
       » Store the metadata to internal storage, in a way that supports queries
         based on MSS
       » Generate and return a unique productID for the producer server
   – Receive notification of outdated data and clean the internal storage
   – Receive and answer queries based on the MSS




   Jyrki Haajanen                                          EOGEO 2001, June 26th - 28th,
                                                           Fredericton, New Brunswick, Canada   8
   INFORMATION TECHNOLOGY         IWICOS Broker
       IWICOS Architecture - End-User System
       • End-User System = Facade + Client Software
       • Facade may contain some of the following features:
              –     Product generation through fusion
              –     Conversion from an IWICOS format to a client specific format
              –     Data filtering for narrow-band communication
              –     Intelligent data gathering based on predefined preferences

     query



Metadata                   Facade
                                                                                         Client Software
Selected Products
                                           query
                                                                   Filtered Metadata
                                                                   Filtered Products




              Jyrki Haajanen                                                       EOGEO 2001, June 26th - 28th,
                                                                                   Fredericton, New Brunswick, Canada   9
              INFORMATION TECHNOLOGY               IWICOS Broker
SOAP - Overview
• Simple Object Access Protocol
• Lightweight XML protocol for exchanging structured and
  typed information on the web
• Requires a lower level transport protocol - but not tied to a
  specific one
• Wraps message content to XML format




   Jyrki Haajanen                              EOGEO 2001, June 26th - 28th,
                                               Fredericton, New Brunswick, Canada   10
   INFORMATION TECHNOLOGY   IWICOS Broker
   SOAP Messages
 POST /StockQuote HTTP/1.1                                           SOAP Request
 Host: www.stockquoteserver.com
 Content-Type: text/xml; charset="utf-8"                             in HTTP
 Content-Length: nnnn
 SOAPAction: "Some-URI"

 <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" SOAP-
 ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
   <SOAP-ENV:Body>
     <m:GetLastTradePrice xmlns:m="Some-URI">
       <symbol>DIS</symbol>
     </m:GetLastTradePrice>     HTTP/1.1 200 OK                                  SOAP Response
   </SOAP-ENV:Body>             Content-Type: text/xml; charset="utf-8"
                                Content-Length: nnnn                             in HTTP
 </SOAP-ENV:Envelope>

                                  <SOAP-ENV:Envelope
                                  xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
                                  SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>
                                    <SOAP-ENV:Body>
                                      <m:GetLastTradePriceResponse xmlns:m="Some-URI">
                                        <Price>34.5</Price>
                                      </m:GetLastTradePriceResponse>
                                    </SOAP-ENV:Body>
                                  </SOAP-ENV:Envelope>

Messages from W3C 'SOAP 1.1 Note' [http://www.w3.org/TR/SOAP/#_Ref477488396]
         Jyrki Haajanen                                                        EOGEO 2001, June 26th - 28th,
                                                                               Fredericton, New Brunswick, Canada   11
         INFORMATION TECHNOLOGY                   IWICOS Broker
IWICOS Broker - Components
        Producer Server -                                             Facade - Broker
        Broker Interface                                              Interface



          newProduct                                                            query


                             Metadata                   Query
 HTTP Request for Metadata
                              Parser                    Engine

       outdatedProduct

          productList
                                            Database




 Jyrki Haajanen                                                  EOGEO 2001, June 26th - 28th,
                                                                 Fredericton, New Brunswick, Canada   12
 INFORMATION TECHNOLOGY                 IWICOS Broker
    IWICOS Broker - Facade Interface
Query                                    Reply
• Presented in XML                       • Presented in XML
• Basic element is an expression:        • Two modes:
• ‘AND’, ‘OR’ and ‘NOT’ operators                – Brief
• Can express a value for MSS type
                                                 – Full
    – exact
    – range
    – enumerated




        Jyrki Haajanen                                     EOGEO 2001, June 26th - 28th,
                                                           Fredericton, New Brunswick, Canada   13
        INFORMATION TECHNOLOGY   IWICOS Broker
IWICOS Broker - Use of SOAP

       Producer                    Broker                      Facade
       Server

       SOAP                        SOAP                        SOAP

       HTTP                        HTTP                        HTTP

       Lower                       Lower                       Lower
       Level                       Level                       Level
       Services                    Services                    Services


           Legend:
                     Virtual Circuit              Physical Circuit




 Jyrki Haajanen                                               EOGEO 2001, June 26th - 28th,
                                                              Fredericton, New Brunswick, Canada   14
 INFORMATION TECHNOLOGY           IWICOS Broker
IWICOS Broker - Use of SOAP


           PRODUCER
             SERVER                                 BROKER
   WEB
  SERVER      Producer Stubs                Broker Stubs
                                     SOAP
                             HTTP




  Jyrki Haajanen                            EOGEO 2001, June 26th - 28th,
                                            Fredericton, New Brunswick, Canada   15
  INFORMATION TECHNOLOGY   IWICOS Broker
IWICOS Broker - Use of SOAP
    PRODUCER                                                              FACADE
      SERVER
Web-Server   STUBS                                                          STUBS
                        outdatedProduct
                                                                 SOAP
           newProduct



                                          productList




                                                                                         query
                                                                 HTTP
                                                                 SOAP



                                                                        Query Engine
    Metadata Parser                                     Metadata
                                                        Storage
                                                                                        BROKER

   Jyrki Haajanen                                                        EOGEO 2001, June 26th - 28th,
                                                                         Fredericton, New Brunswick, Canada   16
   INFORMATION TECHNOLOGY                               IWICOS Broker
SOAP - Evaluation
  +   Not tied to a single lower level protocol (HTTP, SMTP, ...)
  +   Cross-organisational communication is easy to implement (HTTP)
  +   Easier to debug when compared to CORBA, DCOM, RMI
  +   Ideal for publishing existing services on the web

  –   Encoding/decoding of messages
  –   Messages require more space
  –   Setting up the environment may take time at the first try
  –   Reading material is inadequate (at the February 2001)




  Jyrki Haajanen                                       EOGEO 2001, June 26th - 28th,
                                                       Fredericton, New Brunswick, Canada   17
  INFORMATION TECHNOLOGY        IWICOS Broker
SOAP - Adoption Trends

             New References in Northern Light Search Engine Containing Phrase "Simple Object Access
                                                    Protocol"


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               84                       89      94       84
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        47

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                                                                                01




   Jyrki Haajanen                                                                   EOGEO 2001, June 26th - 28th,
                                                                                    Fredericton, New Brunswick, Canada   18
   INFORMATION TECHNOLOGY                       IWICOS Broker
Conclusions
• SOAP - A promising new technology
   – Productivity is high and debugging is easy when compared to binary
     correspondents
• Developer adoption is increasing
• Great promises in combination with the Semantic Web
  technologies, such as
   – Universal Description, Discovery, and Integration (UDDI)
   – Web Services Definition Language (WSDL)
• Supportive literature is required
• Can be applied successfully to implement web-based
  metadata service - technically



   Jyrki Haajanen                                        EOGEO 2001, June 26th - 28th,
                                                         Fredericton, New Brunswick, Canada   19
   INFORMATION TECHNOLOGY        IWICOS Broker
IWICOS Web Sites

IWICOS project web-pages
   – http://www.nrsc.no/~iwicos/

IWICOS broker web-pages
   – http://iwicos.vtt.fi/




   Jyrki Haajanen                              EOGEO 2001, June 26th - 28th,
                                               Fredericton, New Brunswick, Canada   20
   INFORMATION TECHNOLOGY      IWICOS Broker

				
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