Technical data
System Administration Infrastructure
Configuring and Managing WebLogic Server 1-5
System Administration Infrastructure
System administration infrastructure in WebLogic Server is implemented using the
Java Management Extension (JMX) specification from Sun Microsystems. The JMX
API models system administration functions with Java objects called MBeans.
Knowledge of this implementation as described in this discussion of system
administration infrastructure is not necessary to manage a WebLogic Server domain.
There are three types of MBeans used to manage a WebLogic Server domain:
administration, configuration, and runtime Mbeans.
Administration Mbeans contain a set of attributes that define configuration parameters
for various management functions. All attributes for administration MBeans have
pre-set default values. When the Administration Server starts, it reads a file called
config.xml and overrides the default attribute values of the administration MBeans
with any attribute values found in the
config.xml file.
The
config.xml file, located on the machine that hosts the Administration Server,
provides persistent storage of Mbean attribute values. Every time you change an
attribute using the system administration tools, its value is stored in the appropriate
administration MBean and written to the
config.xml file. Each WebLogic Server
domain has its own
config.xml file.
If you set any configuration attributes on the command line when you start the
Administration Server using the
-D arguments, these values override the values set by
the defaults or those read from the
config.xml file. These overridden values are also
persisted to
config.xml file by the Administration Server. For more information
about these command-line arguments, see Configuring Servers.
Configuration Mbeans are copies of Administration Mbeans that each Managed Server
uses to initialize its configuration. When you start a Managed Server, the server
receives a copy of the of all the administration MBeans from the Administration Server
and stores them in memory as configuration MBeans. If you override any
configuration attributes when starting a Managed Server, those values override the
values received from the Administration Server but are not written to the
config.xml
file. For more information about starting a Managed Server, see Starting Managed
Servers.