Bulletproof WebSphere Architectures

Tony Higham, CTO

Rare Medium

What We’ll Cover

Application Architecture Scalability and reliability

Integrating Domino and WebSphere WebSphere V4 software architecture A typical development architecture An example production architecture

Where to Learn More

What is Application Architecture

An application architecture is ... An application run-time environment

(the stuff on which applications run) Hardware, software, networking, etc.

Why should you care about architecture? Success or failure of your applications

depends upon it A well-designed application will run poorly

on a poorly-designed architecture

Application Architecture Goals

A good application architecture provides An application environment that is easily

extensible to provide more computing power as the number of users increases

An application environment that is resilient to hardware and software failure

Use scalable and reliable technologies to meet these architectural goals

Achieving Scalability

Design the architecture to use vertical and/or horizontal scaling Vertical scaling with server software

• Running multiple instances of server software on a single machine

Horizontal scaling with server software• Running multiple machines, each with a

single instance of the server software Both horizontal and vertical, combined

Vertical and Horizontal Scaling

{ }Vertical Scaling

Horizontal Scaling

Machine A4 CPUs, 2 Gbytes RAM

Machine B2 CPUs, 1 Gbyte RAM

Machine C2 CPUs, 1 Gbyte RAM

Server E

Server F

Server G

Server H

Server A

Server B

Server C

Server D

Why Use Vertical Scaling?

A single server instance rarely uses the maximum capacity of a machine Software packages have different limits

• Domino R4.6 uses maximum +/- 750 MB RAM Use multiple instances to exploit the

available CPU and memory resources Beware of vertical scaling tradeoffs

Does not meet reliability goals Performance improvement is not linear

Why Use Horizontal Scaling?

More reliable than vertical scaling Removes single point of failure

Offers the best scaling performance Performance improvement is near linear The more systems you add, the faster it is

Biggest tradeoff is cost One server per machine is costly Best combined with vertical scaling

Achieving Reliability

Hardware reliability is often achieved with redundant CPUs, hot-swap drives, etc. Combines with software redundancy to

remove all single points of failure Software redundancy services provide

Even distribution of work over servers• Reduces likelihood of failure due to high load

Redirection of user requests to other servers in the event of server failure

Designing an Application Architecture

Architecture design is a tradeoff between Scalability Performance Reliability Cost

You decide which tradeoffs make sense Performance and reliability needs Available budget for hardware/software

Integrating Domino and WebSphere

Integration occurs at the HTTP layer Domino HTTP server, or Microsoft IIS Web server

Domino and WebSphere single sign-on WebSphere ships with SecureWay

Directory, which Domino can use (LDAP) WebSphere can use the Domino directory

when it's LDAP-enabled Single sign-on works in Domino R5.05

WebSphere V4 Software Architecture

Application Server

Javaservlet

ccJSPpage

JSPengine

EJB

DatabaseServer

AdministrationRepository

Administrator's Console

Web Browser

HTTP

Administration Server

Embedded HTTP Server(Port 9080)

HTTP Server

HTTP

HTTPSWAS

Plug-In

ApplicationDatabase

WebSphere Advanced Edition

Typical Development Architecture

Browser

HTTP

TCP/IP

firew

all

Domino R5 Server

NSFEngine

HTML

DominoDatabase

WebSphere Server

Servlet JSPEngine

DatabaseServer

WASPlug-in

TIER 1 TIER 2

EJBEngine

RelationalDatabase

HTTP

TCP/IP

LegacySystem

Machine A

HTTPEngine Legacy

Integration

Analysis of the Development Architecture

Issues with this architecture If the machine fails, you're out of business Domino HTTP server has known issues

• Performance, agents causing HTTP server crashes, etc.

How to improve this architecture Use machines dedicated to specific tasks Use a scalable and reliable HTTP server

• HTTP server must integrate with Domino and WebSphere

Example Production Environment

Browser

HTTP

TCP/IP

firewall

TIER 1 TIER n

LegacySystem

HTTPLoad

Splitter

firewall

TIER 2

WebSphereAdvanced

1

DatabaseServer

WebSphereAdvanced

2

HardwareClustering

Domino Server 1

IIS Server

Plug-In

Domino Server 2

IIS Server

Plug-In

Domino Server 3

IIS Server

Plug-In

Domino Server 4

IIS Server

Plug-In

Benefits and Tradeoffs

Benefits of this architecture IIS has proven scalability and reliability Improved security with second firewall Hardware clustering removes single

point of failure for database server Tradeoffs with this architecture

IIS is the only other Web server that Domino and WebSphere can share

• IBM HTTP Server (Apache) is not available!

Where to Learn More

SearchDomino.com Admin2002 Conference

Detailed follow-on session with live demo Fully documented procedures on CD May 1 – 3 in Boston (see www.eview.com)

Articles in The View magazine Ariticles in WebSphere Advisor magazine The ITHumans Web site

www.ithumans.com tony.higham@ithumans.com

Questions?

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