e-Science, the Grid and
Microsoft .NET
Daragh Byrne, Neil Chue Hong, Ally Hume, Mike Jackson
EPCC – University of Edinburgh
http://www.epcc.ed.ac.uk/~ogsanet
ogsanet-queries@epcc.ed.ac.uk
GlobusWorld 2004, San Francisco – January 20th-23rd 2004
Microsoft is a trademark of Microsoft Corporation.
Overview
The MS.NETGrid Project
OGSI on Microsoft .NET – MS.NETGrid-OGSI
Grid Service Demonstrators
Training Courses
The MS.NETGrid Project
Project Goals
OGSADAI
e-Science
Application
e-Science
Application
OGSI
Microsoft .NET
OGSI and
Microsoft .NET
OGSI and
Course
Microsoft
.NET
…
OGSI
… …Course
… … and
Microsoft
.NET
…
OGSI
… …Course
… … and
Microsoft
.NET
…
Course
…………
…
…………
Project Parties
EPCC – University of Edinburgh:
Project management
Design, development and implementation
Authoring training materials
Delivering training courses
e-Science Grid Core Program:
UK Department of Trade and Industry
Funding Grid research and development projects
Microsoft Research Limited (Cambridge):
Technical consultancy and expertise
Provision of training materials
NeSC – UK National e-Science Centre:
Production and negotiation of collaboration agreement
Hosting training courses
OGSI Implementations
Microsoft .NET:
University of Virginia: OGSI.NET Release 2.0
Java:
Globus: Globus Toolkit 3 Release 1.0
Unicore
Perl:
University of Manchester: OGSI::Lite
Python:
Lawrence Berkley National Labs: pyGlobus
So Why Yet Another?
Facilitate uptake of OGSI:
Implementations on different platforms
Go to our target users
Do not expect them to come to us
Research:
Exploit unused features and functionality of Microsoft
.NET
Exploit used features and functionality in a different
way
Competition
OGSI on Microsoft .NET
MS.NETGrid-OGSI
Microsoft .NET In One (Just in case…)
Develop stand-alone or Internet-enabled applications:
Microsoft Intermediate Language (MSIL) – platform-independent
Compilers for C#, C++, Visual Basic …
Common Language Runtime (CLR) – MSIL execution
Distributed computing – ASP.NET, remote method invocation,
XML
Internet Information Services – Web application hosting:
Active Server Pages
SOAP / WSDL-based Web services
ASP.NET:
Active Server Pages and Web service development
Mapping SOAP request/response onto C# method call/return
Tooling to generate client-side stub code from WSDL
Automated generation of WSDL descriptions of services
MS.NETGrid-OGSI Design Dimensions
Use IIS and ASP.NET:
Industry-standard Web services programming model
Maintain integration with existing technology
Facilitate speed of development
Exploit existing knowledge of developers
Utilise .NET class library:
Rich framework for XML programming, serialization etc.
Use an object instance to represent a service instance:
Creating service object and loading state every request is too
costly:


Performance-wise
Development time-wise
Provide a “representative implementation” of the core
aspects of OGSI
MS.NETGrid-OGSI
Architecture based upon GT3-Core
Exploits ASP.NET functionality
Provides support for:
Grid service hosting in ASP.NET Web services
container
Functionality relating to:



GridService
Factory
NotificationSource, NotificationSubscription, NotificationSink
Service data management
Management of persistent and transient services
Client-Service Interaction
C#
Implementation
8. C# method return
Proxy
(from WSDL)
Client
1. C# method call
7. SOAP response
2. SOAP request
HTTP
ASP.NET
Web Service Proxy (.asmx)
3. Grid
Service
ID
C#
Implementation
4. Grid
Service
Object
Reference
5.
Operation
Call
6.
Operation
Return
OGSI Container
Grid
Service
Grid
Service
Grid
Service
Service Access and Naming
Persistent services:
Server-managed services
Necessary for factories, permanent services
Naming:

http://host/ogsa/services/persistent/SomeServiceFa
ctory.asmx
Transient services:
Client-managed services
Naming:

http://host/ogsa/services/transient/SomeService.as
mx?instanceID=someService1
Web Service Proxy Model
Service proxy is standard ASP.NET Web service:
Created => processes request => dies
Communications layer between client and Grid services:
One proxy type (.asmx) corresponds to one or more Grid
services
One instance of a proxy created per service request to .asmx
file
GSH is used by proxy to find Grid service object
Reflection allows invocation of a service method on that object
SOAP communication and WSDL description for free
Familiar model to ASP.NET users
Potential for auto-generation of proxy code from WSDL
Developing a Grid Service
Grid Service Components
SomeGridService.asmx
compiled into
SomeGridServiceProxy
delegates to
Service
Implementation
SomeGridServiceImpl
ServiceDataSet
SomePortTypeProvider
SomeOtherPortTypeProvider
Grid Service Design
What services will your Grid service provide?
What operations will it support?
How are these operations aggregated into
portTypes?
What existing and new portTypes will your
service implement?
No need to write WSDL!
Implement the Service
Analogous development models to those of GT3 /
OGSI.NET:
Extend a class implementing the GridService portType with
additional operations from other portTypes
Provide classes implementing the operations of a specific
portType – PortType Providers
GridServiceSkeleton and
PersistentGridServiceSkeleton classes:
Implement the GridService portType
Contain a service data set
Record a list of other service properties
ServiceData APIs
Notification APIs
Implement the Service – Inheritance
public class HelloServiceImpl :
PersistentGridServiceSkeleton
{
int i = 0;
// sayHello is an operation of a HelloWorld
// portType
public string sayHello(string name)
{
return “Hello, “ + name + “ “ + (++i);
}
}
Implement the Service - PortType
Providers (1)
public class HelloWorldPt : PortTypeProviderBase
{
int i = 0;
public string sayHello(string name)
{
return “Hello, “ + name + “ “ + (++i);
}
public override void Initialise() { }
}
// Declare service and attach portType using attribute
[OgsiPortType(typeof(HelloWorldPt),
“http://www.example.org/hello”, “HelloWorld”]
public class HelloServiceImpl :
PersistentGridServiceSkeleton
{
}
Implement the Service - PortType
Providers (2)
ASP.NET attributes and reflection:
OGSI.NET exploits this technology also and in a similar way
On instantiation of GridServiceSkeleton:
Object reflects upon self to get OgsiPortType attributes
Uses the information in the attributes to instantiate
implementation classes
These are stored – indexed by portType name
IPortTypeProvider interface:
Can be implemented by any PortType Provider class
Provides methods for initialisation and setting a reference to the
main service class
PortTypeProviderBase class:
Implements IPortTypeProvider interface
Implement the Service Proxy
Communications layer between clients and Grid service
objects
Proxies are Web services
Represents the most-derived portType:
Provides methods corresponding to all the operations of all the
portTypes implemented by a service
GridServiceInstanceAspProxy and
PersistentGridServiceInstanceAspProxy:
Corresponding to GridServiceSkeleton and
PersistentGridServiceSkeleton classes respectively
Implement the Service Proxy - Inheritance
// HelloService.cs
public class HelloService :
PersistentGridServiceInstanceAspProxy
{
[WebMethod]
// Any other ASP.NET attributes
public string SayHello(string name)
{
object [] args = { name };
return (string)
CallMethod(“SayHello”, args);
}
}
Implement the Service Proxy - PortType
Providers
// HelloService.cs
public class HelloService :
PersistentGridServiceInstanceAspProxy
{
[WebMethod]
// Any other ASP.NET attributes
public string SayHello(string name)
{
object [] args = { name };
return (string)
CallMethodOnProvider(“HelloWorldPt”,
“SayHello”, args);
}
}
Implement the Service Proxy Complete the Proxy
Write .asmx file which references the proxy
class
<%@ WebService
Class=“HelloService"%>
Deploy the Service (1)
Approach is analogous to GT3 and AXIS/Tomcat
ASP.NET Web.config file – analogous to
server-config.wsdd file
<gridContainer>
. . .
<gridServiceDeploymentDescriptor
asmxFileName=“HelloService.asmx”
serviceClass=“HelloServiceImpl”
assembly=“HelloAssembly”
persistence=“persistent”>
<serviceParameter name=“dbConnect” value=“someDB:location”/>
<serviceParameter name=“key” value=“value”/>
</gridServiceDeploymentDescriptor>
<gridContainer>
Deploy the Service (2)
Copy assemblies to Ogsi.Container/bin/
Copy .asmx file to:
Ogsi.Container/services/persistent/
OR
Ogsi.Container/services/transient/
IIS maps http://host/ogsa/ virtual directory
to Ogsi.Container



http://host/ogsa/services/transient/HelloWorld.asm
x
=>
Ogsi.Container/services/transient/HelloWorld.asmx
Design Limitations
No rich client-side support:
No Grid service-specific support
But Grid services ARE Web services
GSH naming is restrictive
No support for GSR
No support for GWSDL
No ServiceGroup-related portTypes
No HandleResolver portType
No security support
Grid Service Demonstrators
Grid Service Demonstrators
Basic GridService:
Implements GridService portType
Persistent and transient services available, with
factory
Counter Service:
A simple transient counter service which maintains
state
An associated persistent factory service
A client with a graphical user-interface
OGSA-DAI Grid Data Service
Client
Request
(GDS-Perform document)
Response
(GDS-Response document)
(WebRowSet)
Grid Data Service ADO.NET
SQL
Server
Open Grid Services Architecture – Data Access and
Integration
http://www.ogsadai.org.uk
Stripped down from full OGSA-DAI functionality
Training the UK e-Science
Community
Training Courses
“OGSI on Microsoft .NET”
Designed for UK e-Scientists
Four courses each for 25 attendees:
September 9th-10th 2003 - Edinburgh
November 4th-5th 2003 - Edinburgh
January 14th-15th 2004 - London
February 24th-25th 2004 - Edinburgh
UK e-Science Institute:
http://www.nesc.ac.uk/esi
Course Goals
Introduce / review:
Grid services, OGSA and OGSI
Microsoft .NET
Introduce OGSI on Microsoft .NET:
MS.NETGrid-OGSI
Use MS.NETGrid-OGSI to:
Develop Grid services
Develop clients
Course Experiences
Attendees from UK involved in Grid research, astronomy,
particle physics, chemistry, informatics
Majority stated worthwhile attending
Likes:
Practical hands-on use of MS.NETGrid-OGSI was especially popular
Concise introduction lectures and a .NET overview
MS.NETGrid-OGSI was reasonably straightforward to use
Dislikes:
Not enough diagrams and too much detail in text
Not enough time spent on MS.NETGrid-OGSI itself
Majority stated intent to use MS.NETGrid-OGSI for
applications including:
Particle physics, inter-operability testing, benchmarking, .NET
familiarisation
Questions ?