Harvesting, Harvestable Data, and Harvested Data

7 Configuring the Harvester for Metric Collection 7-1 7 Configuring the Harvester for Metric Collection The Harvester component of the WebLogic Diagnostics Framework WLDF gathers metrics from attributes on qualified MBeans that are instantiated in a running server. The Harvester can collect metrics from WebLogic Server MBeans and from custom MBeans. The following sections describe harvesting and the Harvester configuration process: ■ Section 7.1, Harvesting, Harvestable Data, and Harvested Data ■ Section 7.2, Harvesting Data from the Different Harvestable Entities ■ Section 7.3, Configuring the Harvester

7.1 Harvesting, Harvestable Data, and Harvested Data

Harvesting metrics is the process of gathering data that is useful for monitoring the system state and performance. Metrics are exposed to WLDF as attributes on qualified MBeans. The Harvester gathers values from selected MBean attributes at a specified sampling rate. Therefore, you can track potentially fluctuating values over time. Data must meet certain requirements in order to be harvestable, and it must meet further requirements in order to be harvested: ■ Harvestable data is data that can potentially be harvested from harvestable entities, including MBean types, instances, and attributes. To be harvestable, an MBean must be registered in the local WebLogic Server runtime MBean server. Only simple type attributes of an MBean can be harvestable. ■ Harvested data is data that is currently being harvested. To be harvested, the data must meet all the following criteria: – The data must be harvestable. – The data must be configured to be harvested. – For custom MBeans, the MBean must be currently registered with the JMX server. – The data must not throw exceptions while being harvested. The WLDFHarvesterRuntimeMBean provides the set of harvestable data and harvested data. The information returned by this MBean is a snapshot of a potentially changing state. For a description of the information about the data provided by this MBean, see the description of the 7-2 Configuring and Using the Diagnostics Framework for Oracle WebLogic Server weblogic.management.runtime.WLDFHarvesterRuntimeMBean in the Oracle WebLogic Server MBean Reference. You can use the Administration Console, the WebLogic Scripting Tool weblogic.WLST, or JMX to configure the harvester to collect and archive the metrics that the server MBeans and the custom MBeans contain.

7.2 Harvesting Data from the Different Harvestable Entities