Operating Systems: AIX, HP-UX, Linux, Solaris, Windows, z/OS
Dynamic application placement
In WebSphere® Virtual Enterprise, dynamic application placement is based on load distribution, service policy, and available resources. You can run applications at various levels within a WebSphere Virtual Enterprise environment, ranging from changing relative weights of applications to expanding a WebSphere Virtual Enterprise cell. As changes become more drastic and their impacts become more extreme, applications take more time to run.
By dynamically placing resources, WebSphere Virtual Enterprise can utilize hardware more efficiently. It is unlikely that all applications are in high demand at the same time, assuming a varied assortment of deployed applications. WebSphere Virtual Enterprise exploits this situation by supporting resource allocation where needed, thereby increasing the utilization of hardware. The result is that an enterprise no longer requires enough hardware to satisfy each application maximum load simultaneously, which can translate to a significant reduction of requisite IT investments.
The dynamic application placement capability is contained by three autonomic managers: the application placement controller, dynamic workload manager (DWLM), and autonomic request flow manager (ARFM).
Each autonomic manager provides capabilities that work to achieve a common goal, which is to allocate the available capacity among the deployed applications and configured services classes. When it is necessary to modify the capacity that is allocated to a given application, the autonomic manager takes actions starting with the first or fastest level. As changing demand renders these lightweight adjustments ineffective, more drastic measures are required. For example, the WebSphere Virtual Enterprise autonomic managers might start by changing the dispatching priorities of requests that are associated with a service policy. WebSphere Virtual Enterprise makes such adjustments every few seconds. However, such adjustments might be ineffective if the size of a given cluster is too small. WebSphere Virtual Enterprise changes the sizes of dynamic clusters over a time scale of tens of minutes.
Dynamic application placement challenges
The challenge of dynamically placing a given application includes increasing and decreasing its capacity, which can be accomplished at several levels. The decisions on how to change the resource allocations are made using the autonomic managers that monitor various performance metrics, analyze the monitored data, and then guide the planned actions. WebSphere Virtual Enterprise supports various configurable levels of autonomicity. In the most autonomic mode, autonomic managers are granted the freedom to run the actions they plan. In the most manual mode, autonomic managers suggest actions, which an administrator must run manually.
Related concepts
Overview of dynamic operations
Related tasks
Configure dynamic application placement