Introduction to Globus Toolkit 4 at LA Grid CIS 6612 – Autonomic Grid Computing Summer 2006...

Introduction to Globus Toolkit 4

at LA Grid

CIS 6612 – Autonomic Grid Computing

Summer 2006

Presenters Fernando Farfán Mayelin Felipe

Agnostics Diego López Ramakrishna Varadarajan

OUTLINE

WEB SERVICES FUNDAMENTALS GRID FUNDAMENTALS OGSA, WSRF & GT4 LAGRID @ CIS.FIU.EDU DEVELOPING WS IN LAGRID

Unsecured Examples Secure Examples

A SAMPLE APPLICATION: FileBuy

WEB SERVICESDefinition

According to the W3C a Web service is a software system designed to support interoperable machine-to-machine interaction over a network.

Just another distributed computing technology that allows us to create client/server applications.

Note: Information provided by Web Services is intended to be accessed by software, not directly by humans.

Web Services are platform and language independent.

Most Web Services use HTTP for transmitting messages.

Web services can be combined to provide an integrated service.

WEB SERVICESAdvantages

Overhead – transmitting messages in XML

Lack of versatility - not as many features as other distributed computing technologies

WEB SERVICESDisadvantages

WEB SERVICESTypical Web Service Invocation

The Globus Toolkit 4 Tutorial.http://gdp.globus.org/gt4-tutorial/

WEB SERVICESDetailed Web Service Invocation


WEB SERVICESServer Side

handles HTTP messages

provides a 'living space' for applications that must be accessed by different clients

handles SOAP requests and responses


WEB SERVICESAgnostic Question

Can you compare a stateless vs. stateful web service?

Stateless web services don’t “remember” information from one invocation to another whereas stateful Web Services do.

• When Web Services are used just to create Internet-based applications with loosely coupled clients and servers, they can be stateless. The service can be restarted without concern of previous interactions.

Example: the Weather Web Service mentioned in the tutorial

• When Web Services are used to create Grid Applications, they are generally required to be stateful.


What do you think are the tradeoffs of providing the state explicitly within the request message or maintaining the state implicitly within system components with which the web service can interact?

In the paper Modeling Stateful Resources with Web Services the authors mention that the Web service could maintain the resource identity as static service state, thus obviating the need to pass that identity in the WS-Addressing endpoint reference.

This design choice implies a one-to-one mapping from Web service endpoints to stateful resources and thus a need for a unique Web service endpoint for each stateful resource.

WEB SERVICESAchieving Statefulness

• The state is kept in a separate entity called a resource.

• Each resource has a unique key.



The key contributions of WSRF are enabling web services to manage stateful resources and its standardization. What do you think are the advantages of separating state from services and what are the advantages of standardization?

A stateless Web service can be restarted without concern for its history of prior interactions.

Standardization enhances service interoperability.


How do you discover the existence of a service in a grid using Globus ToolKit? Does it have any standard service to do that? How do we discover resources available on the Grid?

The Index Service component of the Monitoring and Discovery Service area of the GT4 collects information about resources in the grid and makes it available.

Users need only know the location of a suitable Index Service in order to discover and monitor all of the resources and services that it indexes.

GT4 also provides a few command-line tools, such as wsrf-get-property and wsrf-query that can be used to retrieve resource properties.

For more information: MDS Documentation

WHAT’S A GRID ANYWAYS? GRID SYSTEM: A system that …

Coordinates resources that are not subject to centralized control.

Using standard, open, general-purpose protocols and interfaces.

To deliver nontrivial qualities of service. GRID COMPUTING: The field of computing science

which concerns with Grid Systems. A GRID: an actual, working Grid system

(i.e. LAGrid). THE GRID: Accessible to the general public, in the

same sense that The Internet is publicly accessed.

OGSA, WSRF & GT4 OPEN GRID SERVICES ARCHITECTURE (OGSA)

VO Management Service. Resource Discovery and Management Service. Job Management Service. … security, data management, etc.

WEB SERVICES RESOURCE FRAMEWORK (WSRF) Specifications under the auspices of OASIS.

OGSA is the architecture, while WSRF is the infrastructure.

OGSA, WSRF & GT4

B. Sotomayor and L. Childers. Globus Toolkit 4, Programming Java Services. 2006. The Morgan Kaufmann Series in Networking.

OGSA AND GLOBUS TOOLKIT

De facto standard for construction of Grid systems.

OGSA evolves from GT2. GT3 includes redesigned elements:

Common notification mechanisms for service registration and service state.

GT3 released in March 2003. GT4 released in April 2005.

OGSA AND GT4Agnostic Question

A key requirement of OGSA is a unique Grid Service Handle, how does the GT4 Toolkit meet this key requirement?

Globus implements the OGSA-specified Grid Service Handle and the Grid Service Reference as network-wide pointers to grid service instances.A client application uses these two services to access the services.

OGSA AND GT4Agnostic Question

How far is the mass-adoption of the GT4 Toolkit? Are there any "marketing" campaigns to expedite the adoption of this Open standard?

Globus Alliance (www.globus.org/alliance), Globus Consortium (www.globusconsortium.org): Publications: ClusterWorld Events and Meetings: SC, GRID, etc. Partners in Industry and Academia Communities.

GLOBUS TOOLKIT 4 – GT4Definition

• Open source toolkit developed by The Globus Alliance that allows us to build Grid applications.

• Organized as a collection of loosely coupled components.

• Consists of services, programming libraries, and development tools.

High-level services

•Resource Monitoring and Discovery Service

•Job Submission Infrastructure

•Security Infrastructure

•Data Management Services

GLOBUS TOOLKIT 4 – GT4Components

GLOBUS TOOLKIT 4 – GT4Java WS Core

• Java WS Core provides APIs and tools for developing Grid services.

• Includes a container based on Apache Axis to host various GT4 services implemented in Java, such as GRAM, RFT, MDS-Index, and our own custom Web Services.

GLOBUS TOOLKIT 4 – GT4Agnostic Question

What feature/service is most useful to you as you work with GT4 Toolkit?

The globus-build-service.sh and globus-deploy-gar scripts use Ant to create and deploy the GAR file so we don’t need to worry about:

• Processing the WSDL file• Creating the stub classes from the WSDL• Compiling the stub classes• Compiling the service implementation• Organizing all the files into a very specific directory structure

GLOBUS TOOLKIT 4 – GT4Agnostic Question

The "Grid" has been around since the mid 1990's, after 10 years of theory/development, is GT4 the most developed Grid Toolkit in existence?

While there is other grid toolkits Globus is considered by some the de facto standard for building Grid solutions.

According to Ian Foster, there is a wide variety of tools for Grid computing such as Condor-G, MPICH-G, Nimrod-G, Cactus, GridPort, NetSolve, Ninf, Access Grid, etc., but essentially all build on the Globus Toolkit as infrastructure.

http://www.gridforum.org/mail_archive/gce-g/2002/Archive/msg00370.html

WHAT IS LA GRID?

“First-ever comprehensive computing grid to link faculty, students, and researchers from institutions across the United States, Latin America and Spain to collaborate on complex industry applications for business and societal needs. ”

•IBM

•Florida International University

•University of Puerto Rico at Mayagüez

•Barcelona Supercomputing Center

•University of Miami

•Tecnológico de Monterrey

http://lagrid.fiu.edu/

LA-GRID @ CIS.FIUGlobus-enabled hosts: ip-comm.cs.fiu.edu la-blade-01.cs.fiu.edu la-blade-02.cs.fiu.edu la-blade-03.cs.fiu.edu la-blade-04.cs.fiu.edu la-blade-05.cs.fiu.edu la-blade-06.cs.fiu.edu la-blade-08-ppc.cs.fiu.edu la-blade-09-ppc.cs.fiu.edu tsunami-linux.cs.fiu.edu starscream.cs.fiu.edu

GETTING READY FOR LAGRID

Globus Identity.Get a Globus Identity certificate issued by the Certificate Authority.http://www.cs.fiu.edu/~esj/globus.html

Security Enrollment.Enroll as a Secure Globus User with Eric Johnson.

Setup environment

SETTING UP LAGRID ENVIRONMENT

Step 1: Download the examples Go to the book's webpage, go to Downloads, and select to

download the source code for the MathService examples and the FileBuy application

Untar/unzip the file by running the following command from the directory where you saved the downloaded file: tar -xvzf gt4book-examples.tar.gz

Step 2: Set the following environment variables Set $GLOBUS_LOCATION to /depot/globus-4 Set $ANT_HOME to /depot/ant-1.x Step 3: Getting a Globus Authentication Model Identity Please visit this page for more information on how to get a

Globus Identity Certificate.

GT4 JAVA WS CORE

Building web services using GT4. Stateful web services! Following WSRF specifications.

WRITE A STATEFUL WEB SERVICE IN 5 SIMPLE STEPS!!

1. Define the WS interface with WSDL.

2. Implement the service.

3. Define the deployment parameters.

4. Compile everything and generate a GAR file.

5. Deploy the service.

OUR FIRST EXAMPLE: MathService

A simple Math web service. Operations: Addition & Subtraction & Get

Value. Resources: Value (integer) & Last operation

performed (String).

MathService: THE 5 STEPS.

Step 1: The WSDL.The Definition

<?xml version="1.0" encoding="UTF-8"?><definitions name="MathService" targetNamespace="http://www.globus.org/namespaces/

examples/MathService_instance“ …>…</definition>

The Definition

<?xml version="1.0" encoding="UTF-8"?><definitions name="MathService" targetNamespace="http://www.globus.org/namespaces/

examples/MathService_instance“ …>…</definition>

The Port Type

<?xml version="1.0" encoding="UTF-8"?><definitions …><portType name="MathPortType" wsrp:ResourceProperties="tns:MathResourceProperties"> <operation name="add"> <input message="tns:AddInputMessage"/> <output message="tns:AddOutputMessage"/> </operation> …</portType></definitions>

The Port Type

<?xml version="1.0" encoding="UTF-8"?><definitions …><portType name="MathPortType" wsrp:ResourceProperties="tns:MathResourceProperties"> <operation name="add"> <input message="tns:AddInputMessage"/> <output message="tns:AddOutputMessage"/> </operation> …</portType></definitions>

The Messages

<?xml version="1.0" encoding="UTF-8"?><definitions …><message name="AddInputMessage"> <part name="parameters" element="tns:add"/></message><message name="AddOutputMessage"> <part name="parameters" element="tns:addResponse"/></message></definitions>

The Messages

<?xml version="1.0" encoding="UTF-8"?><definitions …><message name="AddInputMessage"> <part name="parameters" element="tns:add"/></message><message name="AddOutputMessage"> <part name="parameters" element="tns:addResponse"/></message></definitions>

The Response and Request Types

<?xml version="1.0" encoding="UTF-8"?><definitions …> <xsd:element name="add" type="xsd:int"/> <xsd:element name="addResponse"> <xsd:complexType/> </xsd:element></definitions>

The Response and Request Types

<?xml version="1.0" encoding="UTF-8"?><definitions …> <xsd:element name="add" type="xsd:int"/> <xsd:element name="addResponse"> <xsd:complexType/> </xsd:element></definitions>

The Resource Properties

<portType name="MathPortType" wsrp:ResourceProperties="tns:MathResourceProperties">



</portType>


<portType name="MathPortType" wsrp:ResourceProperties="tns:MathResourceProperties">



</portType>


Step 2: Implementing the Service in JavaThe Bare Bones

package org.globus.examples.services.core.first.impl;

import java.rmi.RemoteException;import org.globus.examples.stubs.MathService_instance.*;import org.globus.wsrf.*;import org.globus.wsrf.impl.*;

public class MathService implements Resource, ResourceProperties { …}

The Bare Bones

package org.globus.examples.services.core.first.impl;

import java.rmi.RemoteException;import org.globus.examples.stubs.MathService_instance.*;import org.globus.wsrf.*;import org.globus.wsrf.impl.*;

public class MathService implements Resource, ResourceProperties { …}


/* Resource properties */private int value;private String lastOp;

/* Get/Setters for the RPs */public int getValue() { return value;}

public synchronized void setValue(int value) { this.value = value;}


/* Resource properties */private int value;private String lastOp;

/* Get/Setters for the RPs */public int getValue() { return value;}

public synchronized void setValue(int value) { this.value = value;}


Step 3: Configuring the Deployment (WSDD & JNDI)

The Service Name<service name=“examples/core/first/MathService” provider=“Handler" use="literal" style="document”>

The WSDL File<wsdlFile>share/schema/examples/MathService_instance/Math_service.wsdl</wsdlFile>

Load on Startup<parameter name="loadOnStartup" value="true"/>

The Common Parameters<parameter name="allowedMethods" value="*"/><parameter name="handlerClass" value="org.globus.axis.providers.RPCProvider"/><parameter name="scope" value="Application"/>

The Service Name<service name=“examples/core/first/MathService” provider=“Handler" use="literal" style="document”>

The WSDL File<wsdlFile>share/schema/examples/MathService_instance/Math_service.wsdl</wsdlFile>

Load on Startup<parameter name="loadOnStartup" value="true"/>

The Common Parameters<parameter name="allowedMethods" value="*"/><parameter name="handlerClass" value="org.globus.axis.providers.RPCProvider"/><parameter name="scope" value="Application"/>

WEB SERVICES IN GT4Agnostic Question

What purpose does JNDI play within the GT4 environment?

The Java Naming and Directory Interface allow us to build directory-enabled applications. This will make our Web service available to client connections through a Web services container.A service (identified by its path) will want to locate its resource home.It can also interact with a variety of directories such as LDAP.


Step 4: Create a GAR file with Ant Process the WSDL to add missing pieces. Create stub classes from the WSDL. Compile stub classes. Compile service implementation. Organize all files into its specific directory structure.

./globus-build-service.sh –d <service base directory> -s <service’s WSDL file>

$ ./globus-build-service.sh \ -d org/globus/examples/services/core/first \ -s schema/examples/MathService_instance/Math.wsdl

$ ./globus-build-service.sh \ -d org/globus/examples/services/core/first \ -s schema/examples/MathService_instance/Math.wsdl

$ ./globus-build-service.sh first$ ./globus-build-service.sh first

or


Step 5: Deploy the Service into a Web Service Container Uses Ant. Unpacks the GAR. Copies the WSDL, compiled stubs, compiled

implementation & WSDD into the GT4 directory tree.

$ sudo –u globus globus-deploy-gar \ org_globus_examples_services_core_first.gar

$ sudo –u globus globus-undeploy-gar \ org_globus_examples_services_core_first

$ sudo –u globus globus-deploy-gar \ org_globus_examples_services_core_first.gar

$ sudo –u globus globus-undeploy-gar \ org_globus_examples_services_core_first

MathService: THE CLIENT

Tests the service invoking both the add and substract operations.

$ java -cp ./build/stubs/classes/:$CLASSPATH \ org.globus.examples.clients.MathService_instance.Client \ https://la-blade-01.cs.fiu.edu:8443/wsrf/services/core/first/MathService


AxisFault faultCode: {http://schemas.xmlsoap.org/soap/envelope/}Server.userException faultSubcode: faultString: java.io.IOException: No socket factory for 'https' protocol faultActor: faultNode: faultDetail: ...

HOW TO MAKE THE SERVICE SECURE??

Create the security-config.xml file.<securityConfig xmlns="http://www.globus.org"> <authz value="none"/></securityConfig>

Modify the deploy-server.wsdd file.<parameter name="securityDescriptor" value="etc/org_globus_examples_services_core_first/security-config.xml"/>

Add the following to the client.static { Util.registerTransport();}…((Stub)mathFactory)._setProperty( Constants.GSI_SEC_CONV, Constants.ENCRYPTION);((Stub)mathFactory)._setProperty( Constants.AUTHORIZATION, NoAuthorization.getInstance());

Our acknowledge to Our acknowledge to Ramakrishna!Ramakrishna!

HOW TO MAKE THE SERVICE SECURE??

Is it secure now?Not really… We just added the skeleton to make it secure.


Current value: 15Current value: 10


Current value: 15Current value: 10

Let’s run it again…

WEB SERVICES IN GT4Agnostic Question

How do I create a Grid infrastructure? Can we use any machine which has the Globus Toolkit's Grid Services installed on it?

To build a Grid, we recommend that you download the Globus Toolkit and follow the instructions in the Globus Toolkit System Administrator's Guide. Both of these are available at the Globus website, http://www.globus.org/toolkit/. The documentation will take you through the process of building the Globus Toolkit software, setting up a Grid information service, setting up a certificate authority or using someone else's, installing the Globus resource management tools on your servers, and installing Globus client tools and libraries for your users.

to be continued …

USEFUL LINKS

Our site! [COMING SOON]http://www.cis.fiu.edu/~mfelip01/CIS-6612/GT4_project.html

Globus toolkit 4 Programmer’s Tutorialhttp://gdp.globus.org/gt4-tutorial/

Globus toolkit 4: Programming Java Serviceshttp://www.gt4book.com/

OASIS.http://www.oasis-open.org/

The Globus Alliance;http://www.globus.org/

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Introduction to Globus Toolkit 4 at LA Grid CIS 6612 – Autonomic Grid Computing Summer 2006...

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