Events-api Concepts

Internal

• events-api User Manual

Metric Source

OS

Remote OS

Valid addresses:

ssh://username@hostaddress:port

"ssh://" protocol implied:

username@hostaddress:port

JBoss Management Controller

jbosscli://admin@1.2.3.4:9999/

"jbosscli://" implied:

admin@1.2.3.4:9999/

The default value, if not specified, is "localhost:9999".

JMX Bus

jmx://admin:adminpasswd@1.2.3.4:2345

Classpath.

Metric Definition

A metric definition is an instance that contains all the information a metric source needs in order to extract a value (reading) for a specific metric.

Metric Definition ID

The metric definition has an ID which uniquely identifies the metric to a metric source. The ID must not include anything that ties that ID to a specific metric source. The same ID can be given to different metric sources, and each metric source will return a different value of the metric. For example, "PhysicalMemoryTotal" uniquely identifies the total physical memory metric in the context of a local or remote operating system instance, "java.lang:type=Threading.ThreadCount" uniquely identifies the JVM thread count metric in the context of a JVM's platform MBean server and "/subsystem=messaging/hornetq-server=default/jms-queue=DLQ:message-count" uniquely identifies the DLQ queue depth metric for a specific broker node, managed by a JBoss management controller.

Metric Source Address

A specific instance of a metric definition can be associated with a metric source via the metric source address.

Relationship between a Metric Definition and a Metric Source

A metric source receives a metric defintion and if the source recognizes the definitions, it returns a value (reading) associated with that definition, in form of a property instance:

List<Property> collectMetrics(List<MetricDefinition> metricDefinitions) throws MetricException;

The method collects all metrics whose definitions are given as argument. If a value corresponding to a specific metric definition from the list cannot be successfully collected, a Property instance with the correct id, type and base unit must is returned, but its value is null. Implementations may log as WARN more details on why the collection failed. Implementations may choose - and they are encouraged - to attempt to start the source in-line, if the source is not already started. They, however, may chose to signal the fact that the source is not started and request an external start. The metric source will throw an exception if if finds at least a metric definition that has a null or different source. This indicates a programming error, not a runtime collection failure.

OS Metric Defintion

Local:

PhysicalMemoryFree

Remote:

ssh://test-remote-host:22/PhysicalMemoryFree

JBoss CLI Metric Defintion

Default (implies the default local jboss instance):

/subsystem=messaging/hornetq-server=default/jms-queue=DLQ/message-count

Remote:

jbosscli://admin:adminpasswd@1.2.3.4:9999/subsystem=messaging/hornetq-server=default/jms-queue=DLQ/message-count

JMX Metric Defintion

jmx://admin:adminpasswd@1.2.3.4:2345/jboss.as:subsystem=messaging,hornetq-server=default,jms-queue=DLQ/messageCount

Type Hierarchy