1. Bulletproof WebSphere Architectures Tony Higham, CTO Rare Medium

2. 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

3. 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

4. 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

5. 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

6. Vertical and Horizontal Scaling

7. 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

8. 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

9. 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

10. 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

11. 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

12. WebSphere V4 Software Architecture

13. Typical Development Architecture

14. 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

15. Example Production Environment

16. 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!

17. 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

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