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Agenda

Case Studies Access control Server Resource Pool Management Server

Performance related lessons

Java's Hotspot technology

JavaOne impressions

New Java avenues

Case Study

Three tiered AAA security server

AAA Server (C based)

DBServer (Java based)

GUI client (Java/Html based)

Case Study

Started on JDK 1.02 currently released on JDK 1.1.8.

Uses Applet, Servlet, and Application technology.

ACME web server used for Servlets

Heavily Multi-threaded. (Thread pool)

Runs on Solaris 2.5 and 2.6

Currently about 600+ installations

Case Study

GUI Lessons

3MB Java applets bad idea

Understand the platform before deploying on it.

AWT sucks.

Case Study

Browser incompatibilities big problem

Can't use "Netscape 4.5 or above"

Consider download times.

Design to minimize long download time.

Case Study

Tools now exist to help

Able to achieve excellent reliability using Java

Language is simple. No C++ clutter

Case Study

No Pointers

No Memory leaks relating to forgotten frees

Achieved Productivity gains

Completed Project < 6 months

Case Study

Make sure that the technology used meets marketing demands.

If not, expect backlash

Case Study

Not well suited for command line applications(CLI).

Wrapped CLI with shell scripts.

No single character read (C/R Required)

C/R required before able to read input

CLI commands are good candidates for native compilers

Case Study

Transaction Server (Java)

Command Line Interface (Java)

Middleware(Java)

GUI client (Html/Java Servlets based)

Case Study

Development on Solaris 2.6/Win95

VisualCafe IDE used Win95

OptimizeIt 3.0 for profiling

Case Study

Used RMI for process communication

ACME web server for Servlets

Client GUI HTML based served up using Servlets

Case Study

JNI Interface to Counter subsystem

Moved from 1.1.7 to 1.2 late in development cycle

Lessons learned

Know how your third party library works.

Profiling does pay dividends

Using lowest common denominator is not always the best way.

Performance Lessons

Profile, Profile, Profile

General Performance tips

Profile, Profile, Profile

Java based profilers

JDK based

OptimizeIt (Linux/Solaris/Windows)

Jprobe (Solaris/Windows)

NuMega (Windows/Only)

Profile, Profile, Profile

Memory leaks(Yes you can have them in Java)

Method hogs (Hot spots)

Excessive Object Creation

Profile, Profile, Profile

Get a feeling of how programs run

Profile different algorithms

General Performance tips

Creating threads are expensive

Thread Pools are good idea

If thread is short lived, think of other ways to get the job done.

General Performance tips

Use buffers when possible

I/O does have some performance issues

General Performance tips

JAR files to minimize requests

Class loading management

Obfuscators & size reduction tools

Install on client system if possible

General Performance tips

String manipulation is expensive

Object Creation is expensive

Use Object Factories

Singleton objects where possible

Casting is expensive

Use Custom container classes

General Performance tips

Bad String temp = new String("Counting "); for (i=0; i < 1000; i++) temp = temp + i + " ..."; System.out.println(temp.toString());

General Performance tips

Better String temp = new String("Counting"); for (i=0; i < 100; i++) { String iString = Integer.toString(i); temp.concat (iString).concat(" ..."); } System.out.println(temp);

General Performance tips

Best StringBuffer tempBuff = new StringBuffer("Counting "); for (i=0; i < 100; i++) { tempBuff.append(i).append(" ..."); } System.out.println(tempBuff.toString());

String Performance

General Performance tips

Excessive Object Creation temp = temp + i + " ...";

Java's Hotspot

Java Hotspot Technology

Suns latest VM Technology

Designed for server based technology

Does not improve GUI performance

Adaptive compilation technology

Java Hotspot Technology

What have I learned using Java?

Java Conclusions

Java is platform independent (Mostly)

Java is a productive language

Java does have some performance issues.

Can produce highly reliable code.

Java has come a long way in a very short time

JavaOne

Biggest developer's conference

21,000 developers

International flavor

Large ISV turnout

Java love feast

JavaOne

kJava

JINI (Plug and Work)

Possible Language changes

Enumeration

Paramertized types

Operation overloading

JavaOne

kJava Technology Demos

Palm OS running a Java VM

Motorola SkyPager Running Java

Interactive TV Demos

JINI

Laser Tank Demo

JavaOne

IBM's VM port to Linux

VisualAge for Linux

Java Card Demo

Java Car

JavaOne

Embedded Java

All the ISV activity

Lots of Goodies

tshirts, pens, 8 in one tool, Magic 8 ball etc.

JavaOne

Lines, Lines, and more Lines

Conference Mascots

Lack of a JDK port commitment for Linux from Sun

JavaOne

Java has not been slowed by MS

Lots of opportunities

Java is expanding

Performance is improving

New Java avenues

Java New Technologies

JINI

Plug and Work

Micro Java (kJava)

JavaTV

JavaPhone

Hot Java Links

Java Grande

http://www.javagrande.org

Java One

http://java.sun.com/javaone

Alpha Works (IBM)

http://www.alphaworks.ibm.com/

JavaSoft

http://java.sun.com

JavaWorld

http://www.javaworld.com

Java Lobby

http://www.javalobby.org/

IBM Java

http://www.ibm.com/developer/java/

Gamelan

http://www.gamelan.com/

How to contact me

Cisco

rlamb@cisco.com

Home

ralamb@earthlink.net