JMX is a standard for managing things through Java,
where "managing things" means getting information about and performing
operations on software objects. Managed objects are represented by
MBeans ("Management Beans"), and they are accessed through MBean servers.
To manage an object, an application obtains a reference to the MBean server in
which the object's MBean is registered and then sends
requests with the name of the MBean to get or set MBean attributes, or invoke
MBean operations.
The SMF JMX Agent currently lives in usr/src/java/org/opensolaris/os/smf/jmx
in the vp source. When it is started, it walks the SCF repository, creates
an MBean for each service (instance), and registers them in the JVM's platform
MBean server (essentially the default one). It then listens for service
creations or
deletions, and creates new MBeans or destroys MBeans as appropriate.
SMF service MBeans are defined by the org.opensolaris.os.smf.jmx.Service
class, and have names (instances of the ObjectName class) of the form
"org.opensolaris.os.smf:type=service,service=<service_name>,instance=<instance_name>",
where service_name is the service name component of the service's FMRI,
and instance_name is the instance name component.
The service MBeans currently offer a static interface which exposes both
low-level semantics (individual properties) and high-level semantics
(dependencies, methods, temporary enable, etc.).
Attributes include Enabled, Restarter, State, and NextState.
Informational operations include getMethodNames, getPropertyValues, and
getDescription,
and action operations include restart, refresh, and maintain.
See load_services() in usr/src/cmd/vp/vp/Overview.java for how vp
obtains the list of names of service MBeans. See
usr/src/cmd/vp/vp/ServicePanel.java for examples of retrieving information
from service MBeans, and invoking operations (invoke() calls).
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