apache > ws.apache

## Apache Muse - WS-DistributedManagement - Metrics Capability

Spec name and port type: WS-DistributedManagement v1.1 (no port type)

Capability URI: http://docs.oasis-open.org/wsdm/muws/capabilities/Metrics

Description: This capability defines the muws2:CurrentTime property and, more importantly, manages the metric-related metadata for any resource property that is declared to be a WSDM metric. The MUWS Part 2 spec contains the definition of the various metric types and semantics - Muse's default implementation of the capability automatically updates the metric metadata when property values are updated and provides an API for accessing the metadata without parsing raw XML from WSRP GetResourceProperty.

Java interface: org.apache.muse.ws.dm.muws.Metrics

> JAR file: muse-wsdm-muws-api.jar

Default Java implementation: org.apache.muse.ws.dm.muws.impl.SimpleMetrics

> JAR file: muse-wsdm-muws-impl.jar

Action on initialize(): Reads through the resource's WSRMD document (if one exists) and, for each property that has WSDM Metrics metadata, creates listeners on the property that will update the metric metadata as appropriate. These listeners serve to store and update metric metadata, as well as to attach it to the results of WSRP GetResourceProperty requests so that clients can read it.

Action on initializeCompleted(): None.

Action on prepareShutdown(): None.

Action on shutdown(): None.

Non-Core Dependencies:

- The Abstract WSDM MUWS Capability

Behavior and Limitations: Metric metadata can be added to any resource property programmatically, but Muse provides a way to do it at design time using the WSRMD document. The wsrmd:Property element of a WSRMD document can be extended to include additional metadata child elements, the names and values of which are described in the MUWS Part 2 specification. The most important child element is the muws2:Capability element, which must have the value of the Metrics capability URI (above). The presence of this capability URI tells Muse that the property is a metric and that other metric metadata should be loaded from the WSRMD document. If there are any logical inconsistencies in the use of the metric metadata, the capability will fault during initialization.

Initialization parameters: None.