z/Journal: So, tell me, Steve, what problems were you trying to solve?
Steve Womer: Nationwide has a large number of distributed servers. Most of the servers have a peak utilization of less than 50 percent, with an average utilization between 5 and 15 percent. Our server provisioning time was measured in months to acquire and configure a new server. Dynamically allocating processing power was difficult, for example, whenever a given application needs more processing power on Mondays, or during the end of month. For these reasons, we typically over-provisioned the servers in our distributed world. We also were facing a data center power and floor space scarcity, and potentially tens of millions of dollars investment to upgrade. Finally, Nationwide was looking for an opportunity to dramatically reduce the TCO [Total Cost of Ownership] of our distributed server and Web hosting environment.
z/J: Please tell our readers what made mainframe Linux attractive to you.
SW: Nationwide could address all our identified issues with a mainframe Linux solution. The mainframe’s ability to share resources across multiple applications and workloads was very appealing. The concept of sharing resources and virtualization is well-tested in the mainframe world. The hypervisor software (z/VM) is more than 40 years old and Nationwide already has deep experience with it. The pricing model for running the OS and middleware on zSeries IFLs [specialty mainframe processors designed to run Linux workloads] is significantly different from traditional z/OS or distributed platforms.
z/J: Did you have prior experience running Linux on the mainframe?
SW: Yes, Nationwide had previously tested running some simple applications on MF Linux. In addition, before I came to work at Nationwide, I had about three years of experience in designing Linux solutions in another mainframe environment.
z/J: Please tell us more about the technology building blocks involved.
SW: What did we build? We used two z/990 servers with z/VM 5.1 as the hypervisor. We currently have both Red Hat Linux AS 3.0 and SuSe Enterprise Linux 9 deployed in a three-tiered architecture, leveraging WebSphere 5.1, MQ, and Portal Server. We’ve built a redundant, highly available environment, complete with a replicated disaster recovery solution for our production environment. The environment was mapped to our J2EE [Java 2 Enterprise Edition] reference design, as shown in Figure 1, where IHS is the IBM http server, WAS is WebSphere, and DB at this point is DB2 UDB 8.