TS-1188

12005 JavaOneSM Conference | Session TS-1188

John ArmstrongArchitectural LeadYolus Limitedhttp://www.yolus.comSession TS-1188

Developing a Scalable Distributed Server with JMX™

2005 JavaOneSM Conference | Session TS-1188 | 2

Learn how Java™ ManagementExtensions “JMX™” were used as the cornerstone of a scalable and manageable banking system distributed across several servers

Configuring and managing a Distributed ApplicationAchieving Scalability With JMX


Agenda

Outline of the problemWriting self describing servicesManaging complexityReducing the develop/deploy/test cycleImplementation difficulties



Agenda


The Problem

• It is a given that you must componentize• Scaling to 1000s of interdependent components

is the major challenge• Separation of development and deployment• Reduce the develop/deploy/test cycle• Achieve code reuse in the large


Three Tier Architecture


JMX API Based Component Architecture


DEMOConfiguration of a Risk Management Server



Agenda


The Different Types of MBean


Choosing the Type of MBean

• Writing an MBean should be as easy as possible• All MBeans should have documentation• MBeans should have a reasonable GUI to

configure them• It should be easy to write management tools


Comparing the Types of MBean

ModelOpenDynamicStandard

YesBuilt in features

YesEasy to write tools

YesAuto GUI

OptionalRequiredOptionalDocumented

YesEasy to write


The Hello World Standard MBeanpublic class MyService implements MyServiceMBean {

private String message = "Hello World!";

public String getMessage() {return message;

}

public void setMessage( String message ) {this.message = message;

}

public void printMessage() {System.out.println( message );

}}


Making OpenMBeans Easy

• Generate a wrapper (OpenProxy) for your service that uses restricted parameter types:• Primitives → Wrapper classes• JavaBeans™ Specification → CompositeData

• Generate MBeanInfo using introspection and serialize it so it’s available even if the class is not

• Use Annotations or XDoclet to add metadata• Automate this with ant


Auto Generated Proxy and MBeanInfo


An MBean With Annotations@MBean (

description="A service that prints a message")public class MyService {

private String message = "Hello World!";

@MBean (description="The message to print out"

)public String getMessage() {

return message;}

...}



Agenda


Issues Not Addressed by JMX API

• A naming convention• Hierarchical path names/Standard keys

• A component lifecycle• An “mbean deployed” method at least

• An index of available MBeans• A format must be defined

• An error reporting convention• An “mbean OK” property at least

• Starting JVM™• Use a JMX API enabled daemon process


Finding Other Components

• Synchronous or asynchronous lookup?• Simplicity vs. flexibility and robustness

• Start-up order• Deduce, configure or don’t care?

• Attribute based lookup or naming


Variations

• Maintain consistency between similar but distinct configurations• Development, UAT and Production• Production and a Failover system• Tokyo Server and New York Server


J.F.C/Swing Applications

• Build your own “J.F.C./Swing” clients from configurable components, for example:• Charting plugin• Menu Manager• Options property sheet

• Monitor client components at runtime• Guarantee the same code is used by client

and server



Agenda


Testing

• Lightweight JMX technology can be used to deploy components in unit tests

• Configure and manage automated tests• Add self tests to your components


Class Loading

• Hot deploy components• Reduce the develop-deploy-test cycle

• Deploy all code to a web server• Consistent code across the network• Simply build code to deploy it


Problems With Class Loading

• Conceptually difficult—one classpath causes enough problems!• Use a simple class loader hierarchy• Add classpath entries to your jar files


Problems With Class Loading

• You must use a decent security policy• Use a custom SecurityManager to provide diagnostics• Use https in development

• Downloading code is slow• Use a custom “jar” URL protocol handler



Agenda


Implementation Difficulties

• Complexity of asynchronous lookup• Security and robustness of lookup service• Lack of tool support for RMI activation


Summary

• Manageability is the key to building a scalable distributed server• Self documenting components• Automated lookup• Variations

• Manageability speeds development• Visualize the architecture• Easily deploy new code• Automate testing


Q&A


Submit Session Evaluations for Prizes!

• You can win a $75.00 gift certificate to the on-site Retail Store by telling Sun what you think!

• Turn in completed forms to enter the daily drawing• Each evaluation must be turned in the same day as

the session presentation• Five winners will be chosen each day (Sun will send

the winners e-mail)• Drop-off locations: give to the room monitors or use any

of the three drop-off stations in the North and South Halls

Note: Winners on Thursday, 6/30, will receive and can redeem certificates via e-mail.

Your opinions are important to Sun

322005 JavaOneSM Conference | Session TS-1188

John ArmstrongArchitectural LeadYolus Limitedhttp://www.yolus.comSession TS-1188

Developing a Scalable Distributed Server with JMX

Documents

TS-1188