Chapter 8: External WebSphere System Availability

It's all well and good that you may have a highly available, high-performing WebSphere environment, but if your critical network infrastructure component and external systems aren't performing well, then you may as well run your production WebSphere environment on your home PC!

In this chapter, I'll discuss some guidelines for high availability in external systems and components such Network File System (NFS) and Lightweight Directory Access Protocol (LDAP) servers, firewalls, and database components .

WebSphere's Reliance on Available External Systems

WebSphere's power is its ability to interface with myriad external systems to provide a centralized application delivery platform. Like many enterprise application systems, WebSphere's value is its ability to obtain data from almost any source and, through smart application development, combine that data to form value-driven output.

Because of this ability to interface with many third-party systems, it's important to understand and recognize the implications of interfacing with systems that may themselves be single points of failure or lack any solid performance or availability architecture mechanisms. Although this book isn't a book about how to best architect a Java 2 Enterprise Edition (J2EE)/WebSphere-based application, it is about ensuring that you have a guide when interfacing WebSphere with other non-WebSphere platform products.

Therefore, in this chapter, you'll look at a few of the more common platform derivatives:

• LDAP servers

• NFS servers

• Network infrastructure (routers, firewalls, and load balancers)

• Database failover considerations

By the end of this chapter, you'll understand what to consider if you have to interface any of these non-WebSphere systems with your core platform. This chapter isn't about necessarily how to configure those systems but about what aspects of the platform, systems, or technical architecture you need to be wary of when integrating with WebSphere.