The following example describes an integrated environment where several servers are functionally interacting. This environment is consolidated onto a single zSeries machine. As part of the consolidation, the functional relationship between the servers with the required inter-server communications is implemented with the virtual communication methods of the zSeries environment.
One of ISPCompany's outsourcing clients has been running four small servers that made up the environment for their static Web serving. The machines were located in one of the cages that ISPCompany maintains for its clients' hardware. When an increasing workload necessitated an upgrade of the client's infrastructure, a TCO analysis showed that with the expected growth rate for the next three years, it was advantageous to rehost the servers in Linux images on a ISPCompany zSeries machine (Figure 19-2). The TCO considerations also included savings on network components, flexibility due to virtualization, and simplified administration.
Figure 19-2. Integrated Web-serving environment using z/VM communications
The rehosting is transparent to everyone accessing the Web pages. ISPCompany can easily scale this environment on behalf of its client either horizontally by running more Web server images or vertically by assigning more resources to the existing images.