542 Enabling dynamic clusters Dynamic clusters work with autonomic managers

5.4.2 Enabling dynamic clusters Dynamic clusters work with autonomic managers, including the application placement controller and the dynamic workload controller, to maximize the use of computing resources. Dynamic clusters are required to achieve the server consolidation benefits that are offered by the Intelligent Management features. With the Intelligent Management function, you can define performance goals and bind them to specific subsets of the incoming traffic. The ODR and associated autonomic managers support business goals in times of high load. They do so by making workload management decisions about the work that is being sent through the ODR. Not all the work in a configuration is equally important. The ODR can support this concept by forwarding different flows of requests more or less quickly to achieve the best balanced result and maintain the quality of service. Remember: A service policy is a user-defined categorization that is assigned to potential work as an attribute that is read by the ARFM. You can use a service policy to classify requests based on request attributes. These attributes included the Uniform Resource Identifier (URI), the client name and address, HTTP headers, query parameters, cookies, time of day, and so on. By configuring service policies, you apply varying levels of importance to the actual work. You can use multiple service policies to deliver differentiated services to different categories of requests.

134 WebSphere Application Server V8.5 Concepts, Planning, and Design Guide 5.5 Health management You can use the health management feature to monitor the status of application servers. You can use this monitoring to sense and respond to problem areas before an outage occurs. You can manage the health of an environment with a policy-driven approach that enables specific actions to occur when monitored criteria is met. For example, when memory usage exceeds a percentage of the heap size for a specified time, health actions can run to correct the situation. Health monitoring can help you with both unexpected issues and unanticipated problems in your environment. It can help you bypass problems that would otherwise disrupt operations and affect performance. Consider the Intelligent Management health management feature if you want the following capabilities: Automatically detect and handle application health problems without requiring administrator time and intervention Intelligently handle heath issues in a way that maintains continuous availability Requires administrator approval before an autonomic action is run Treats different applications in different ways, because not all of applications have the same health policies The health management feature consists of the following components: Health policies Health controller 5.5.1 Health policies With health management, you define health policies . A health policy works like a service policy, except that the health policy provides a health goal for the environment. Each health policy consists of a condition, one or more actions, and a target set of processes.