10 th Lecture COP 4991 Component-Based Software Development Instructor: Masoud Sadjadi

10th Lecture

COP 4991 COP 4991 Component-Based Software DevelopmentComponent-Based Software Development

Instructor: Masoud Sadjadihttp://www.cs.fiu.edu/~sadjadi/Teaching/

WSRF.NETWSRF.NET

http://www.cs.fiu.edu/~sadjadi/Teaching/

10th Lecture 2COP-4991: Component-Based Software Development

AcknowledgementAcknowledgement Fernando Trigoso


OutlineOutline WSRF.NET Architecture Attribute-based programming Compatibility with GT4 WSRF Issues


BackgroundBackground WSRF

– WS-Resource WS-ResourceProperties WS-ResourceLifetime

WS-Notification


WSRF.NETWSRF.NET Open source implementation of WSRF and WS-Notification Implements full set of specifications Useful to evaluate the WSRF approach To make programming WSRF.NET services as easy as

programming Web Services


WSRF.NET ArchitectureWSRF.NET Architecture

ISAPI Filter

Wrapper Web Service

Author’s Service

Imported port type functions

WS-Resource

WS-Resource

WS-Resource

WS-Resource

IIS ASP.NETWS-Resource

“Backend”

Internet Information Services (IIS) Internet Server Application Programming Interface (ISAPI)

Humphrey, M., & Wasson, G. (2004). Architectural Foundation of WSRF.NET.



ISAPI Filter

Wrapper Web Service

Author’s Service


WS-Resource

WS-Resource

WS-Resource

WS-Resource


“Backend”

ASP.NET with Web Services Extensions (WSE) Wrapper Web Service automatically created by WSRF.NET




ISAPI Filter

Wrapper Web Service

Author’s Service


WS-Resource

WS-Resource

WS-Resource

WS-Resource


“Backend”

WS-Resource implemented with ADO.NET Serialized result returned to client



WS-ResourceWS-Resource WS-Resource implementation Ability to query complex states Ease to access multiple resources Lookup based on key and state contents

Database

Wrapper

Author’s Web Service

State of Resource


WS-ResourceWS-Resource Portability, scalability and flexibility No single-point of failure Efficient expiration check Provides an interface for customization

Database

Wrapper

Author’s Web Service

State of Resource




Declarative & ImperativeDeclarative & Imperative Imperative programming

– Most common– Methods define behavior of programs

Declarative programming– Declarations define behavior– No need to write instructions– Attributes are used to define behavior

Wagner, B. (2005). Effective C#.

[WebMethod]public string Hello(){return “Hello World”;}


WSRF.NET Attribute UsageWSRF.NET Attribute Usage Attributes easily define:

– Resources– Resource Properties– Port Types

Aids development of grid services


Attributes for Web ServiceAttributes for Web Service

[WebMethod]public string Hello(){

return “Hello World”;}

[WebMethod]public DateTime GetDate(){

return DateTime.Now;}

Used to create the service logic ASP.NET creates:

– WSDL document– Support to route SOAP requests– HTML pages to test web service

Security provided by WSE


Attributes for Stateful Attributes for Stateful ResourceResource

class PackageService{

[Resource]Package pkg;

[Resource]PkgRoute route;

[Resource]PkgLocation location;

…

WS-Resource is an abstraction for a collection of state

WS-Resource addressed by EPR Resource is the collection of

members with [Resource] attribute

Wasson, G. (2006). WSRF.NET 3.0 Programmer’s Reference.







…

Resource stored in the database with key:

– URL + Resource Unique ID EPR in SOAP message contains:

– <Address> + <ReferenceProperties>

Resource loaded from database Values placed in web service’s

members








…

WSRF.NET allows customization Just implement IResource Not all web methods require all

values



Attributes for Resource PropertiesAttributes for Resource Properties



[ResourceProperty]public string Sender{ get {

return pkg.Sender; }}

…

Resources described in Resource Property Document (RPD)

RPD is composed of ResourceProperties

All members with [ResourceProperty] define RPD



Adding Port Types to the ServiceAdding Port Types to the Service[WSRFPortType(typeof(GetResourcePropertyPortType))][WSRFPortType(typeof(ImmediateResourceTerminationPortType))]public class PackageService{


…

WSRF defines functions that may be supported WSRF.NET implements all current specifications Author’s can reuse them by declaring attributes





Compatibility with GT4Compatibility with GT4 GT4 uses a different version of WS-Addressing than WSE

3.0 WSRF.NET makes process transparent GT4 clients can interact with WSRF.NET services and vice

versa (being tested) WSRF.NET cannot send Notifications to both GT4 and

WSE 3 services at the same time


WSRF.NET & GT4WSRF.NET & GT4

B. Sotomayor and L. Childers. Globus Toolkit 4, Programming Java Services. 2006.




Stateful vs. StatelessStateful vs. Stateless Service Oriented Architecture

– Combines loosely coupled and interoperable services State clashes with Services Architecture Bond between client and service

– Loose coupling with stateless services– Tighter coupling with stateful services

Proxies mask services as objects


Complexity of Service-Side Complexity of Service-Side CodeCode

Importing port types may raise issues– Port types have their own resources

The state and its Resource Property– If one changes the other one has to change

Unintuitive interface:

// No WSRF:

CheckPackageIn(Package pkg, string location)

// WSRF:

CheckPackageIn(string location)



ConclusionConclusion WSRF.NET architecture Complex application logic requires complex infrastructure WSRF potential is strong Decoupling will be difficult WSRF.NET helps WSRF


ReferencesReferences Architectural Foundations of WSRF.NET by M. Humphrey

and G. Wason. The Open Grid Services Architecture, Version 1.0. I.

Foster, H. Kishimoto, A. Savva, D. Berry, A. Djaoui, A. Grimshaw, B. Horn, F. Maciel, F. Siebenlist, R. Subramaniam, J. Treadwell, J. Von Reich. Informational Document, Global Grid Forum (GGF), January 29, 2005.

Documents

10 th Lecture COP 4991 Component-Based Software Development Instructor: Masoud Sadjadi