Virtualization options

Running Intelligent Management in an environment with server virtualization has advantages, because of the juxtaposition to hardware and the operating system. With application infrastructure virtualization, you can separate applications from the physical infrastructure on which they are hosted. Workloads can then be dynamically placed and migrated across a pool of application server resources, which allows the infrastructure to dynamically adapt and respond to business needs.

While there are benefits to server virtualization, this virtualization option can sometimes be too far removed from the application layer, and can therefore lack a quality of service based on application information, such as response times and response codes. Application infrastructure virtualization, on the other hand, can provide a quality of service at the application layer. Additionally, this virtualization option provides optimization and autonomic health corrections for the middleware layer through the use of Java™ virtual machines (JVMs). In other words, Intelligent Management minimizes the footprint that is required by the middleware layer, and keeps the middleware highly available through health management. A third benefit of application infrastructure virtualization is the application-demand-driven optimization of the operating system and virtual machine layers. In this sense, the application infrastructure virtualization layer optimizes the server virtualization layer by creating and deleting virtual machines as needed to meet application demand. This is a fully autonomic and optimized private cloud, minimizing the overhead, especially memory, that is incurred by idle virtual machines.

Table 1. Differences between virtualization options
Server virtualization	Application infrastructure virtualization
Hardware is separated from guest operating systems	Application server container is separated from the application
Increases server hardware utilization with server virtualization being used to create a pool of server resources	Increases application server container utilization with application infrastructure virtualization being used to create pools of application server resources
Leverages a layer of insulation that is called the hypervisor	Leverages a layer of insulation that is called the application fabric or application server virtual layer
Resource groups can be assigned resource profiles that are connected to quality of service needs	Application server resources are assigned to dynamic clusters to which applications are deployed
Equates to pinning more cores to the guest operating system (vertical scaling) as opposed to assigning more guests to the server (horizontal scaling)	New JVMs can be restarted in the dynamic cluster to scale out or can be shut down to scale down
Resource sharing is controlled by policies that are expressed in terms of hardware units (CPU cores, memory size)	Resource sharing is controlled by policies that are expressed in terms of what end users see (response time)
Has visibility to the hardware and guest operating system layers	Has visibility to the application, middleware, guest operating system, and hardware layers