1. Chapter 7 Problem & Cases TC 3 Rethinking Rocky Mountain #1, 2

2. TC 3 • Assume that the deployment environment for a high-volume payment processing system consists of the following: • DB2 DBMS running under the OS/390 operating system on an IBM S/390 mainframe • WebSphere application server running under the Z/OS operating system on an IBM zSeries 900 mainframe • CORBA-compliant component-based application software written in Java that will be executed by other internal and external systems • What are the key architectural design decisions that must be made for the system? When should the decisions be made and who should make them? Outline the subsequent design tasks that should occur after the key architectural design decisions are made. To what extent can the subsequent steps be performed in parallel?

3. TC 3 Answer • Some key architectural decisions to explore include: the key components and subsystems, where each component will execute and how will all of the pieces interoperate (which requires nailing down how the network, CORBA, and database infrastructure will be configured)? • Many of the decisions depend on whether the supporting infrastructure is already in place. If it is, then many of the architectural decisions can be delayed until much code has been written and tested. If not, then the required infrastructure and tools will have to be acquired and configured. • Developers will have to be trained, and architectural design will need to occur early to ensure that the developers don’t make any “mistakes” due to lack of fit with the development or deployment environment. Note that an OO development approach is assumed given the nature of the infrastructure and tools

4. Rocky Mountain Outfitters 1 • Various application deployment environments can meet the requirements of RMO’s strategic plan. The staff’s current thinking is to move more toward a Microsoft solution using the latest version of Microsoft Server with Microsoft’s IIS as the Web server. However, Linux with Apache servers is a competing approach. Considering that RMO could also take that approach, do the following: [drawn from SADCW Ch.8] • 1. Compare the relative market penetration of Microsoft and Apache/Linux (a good starting place is http://www.netcraft.com)

5. Rocky Mountain Outfitters 1

6. Rocky Mountain Outfitters 2 • Modify the network diagram in Figure 7-13 to describe a viable architecture using Apache/Linux. What changes, if any, are required for the client workstations and customer PCs? What changes, if any, are required in middleware and communication protocols? Will there be any change in the estimates of required data-communication capacity among client workstations and servers located at the Park City data center? Why or why not? • Using UNIX opens the possibility of deploying Java on the clients, which would increase the communication capacity requirements if applets were transmitted to and executed on clients • Since Microsoft no longer includes “standard” support for Java in Windows or IE, deployment would be complex since presumably some remote clients and customers would be running Windows. They’d have to install a JVM and probably another browser (e.g., Netscape) or a custom application that mimicked a browser.