Welcome to Web Services & Grid Computing Jens Mache
Organisatorisches Pruefungsleistung: Laborarbeit Zeiten: Mittwoch bis Freitag 8 bis 17:20 Pausen: 13-14, (9:30, 11:20, 3:30) “Sage on the stage” versus “Guide on the side”
Die Themen Web Services: Anwendungen und Dienste nach aussen bekannt und nutzbar machen –Zitat: Web Services sind das fuer Rechner, was Webseiten fuer Menschen sind Jedes an einem Grid beteiligte Einzelsystem kann –eigene Resources kontrolliert anbieten –fremde, moeglicherweise heterogene R. nutzen –unternehmensuebergreifend und ueber geographische Grenzen hinweg
Grid vision/ the name Does everybody generate electricity? –No. Plug into the “electric power grid”. Need more computational power, more storage etc.? –Plug into “a grid”. Fine introduction at gridcafe.web.cern.ch/gridcafe
Grid Hype
Web Services Introduced in the 2000s. Software components designed to provide specific operations (“services”) accessible using standard Internet technologies and standardized protocols. The specific standards and protocols will be described shortly. For machine interaction over a network.
Key aspects Has similarities with RMI and other distributed object technologies (CORBA etc.) but: Web Services are platform independent – They use XML within a SOAP message. – Most use HTTP to transmit message. (thus no problems with firewalls, NAT etc.)
Steps to access a web service in a Service-Oriented Architecture Client (Service requester) Server (Service provider) UDDI Service registry Publish Find WSDL Service definition UDDI Service definition Location of service Give me your WSDL WSDL Request service operation Result HTTP WSDL Service description UDDI Service discovery SOAP + XML Service invocation Service message transport ActivityProtocol/language
Example: Amazon WS Register Download Unzip Double-click AWS4JavaSample.jar Read “How to” & try it out Take “screen shots” for Laborarbeit