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The JSR-77 specification defines a management information model called the J2EE Management Model for the J2EE platform. The J2EE Management Model is a specification of the attributes, operations, and architecture of the managed objects required by compliant J2EE platform implementations. This model is inter-operable with a variety of industry standard management systems and protocols. It also provides standard mappings of the model to the Management Information Base (J2EE MIB) and to a Java API as a server resident EJB component.
The scope of this specification is the management of J2EE servers, application components that are deployed onto a J2EE server and resources which provide the J2EE standard services. The information and the operations required by the specification is to enable basic functionality for the following which are defined as the elements of the J2EE MIB:
Managed Object: Discovering and navigating the managed objects on a managed system.
Events: Receiving notifications of important events that occur on managed objects.
State Management: Observing the state of the managed objects.
Performance monitoring: Monitoring basic performance statistics of managed objects.
The J2EE MIB defined in the JSR-77 specification is available as J2EE-MIB.txt under <SNMP Adaptor Home>/mibs directory.
This MIB module is used to discover and monitor details about J2EE servers. The status of the server and its components is reported as MIB objects which can be polled and may also be reported as traps. Optional performance statistics are also defined. The J2EE management model allows multiple servers on a single node as well as single servers spanning multiple nodes. The MIB is defined and indexed in support of this and permits many but not all alternatives in agent and instrumentation architectures; these may be based on monolithic SNMP frameworks. All of the following are supported:
Components of different multi-node servers may coexist on a node, from one or more vendors.
The agent might reside on a node which does not host any component of a server.
A J2EE management domain (part of the J2EE management model) can span multiple servers and hence multiple nodes.
Servers and domains may share nodes with other SNMP-managed components.
A master agent might be present, with sessions to one or more sub-agents having access to a server’s instrumentation.
The elements of the J2EE management model are discussed in the following paragraphs:
The term Managed Object refers to a unit of management information. Management instrumentation provides the "glue" which takes the information available on an entity to be managed and makes it appear as a collection of managed objects. The following image shows the hierarchies of J2EE Managed Object details which are self-explanatory.
Events notify management applications that need to react to state changes and specific conditions that occur in the platform containers and services. The following are the notifications defined in the JSR-77 J2EE MIB:
j2eeServerStateChange: A server entered RUNNING, STOPPED, or FAILED state.
j2eeEntityBeanStateChange: An entity bean entered RUNNING, STOPPED, or FAILED state.
j2eeMessageDrivenBeanStateChange: A message-driven bean entered RUNNING, STOPPED, or FAILED state.
j2eeResourceStateChange: A resource entered RUNNING, STOPPED, or FAILED state.
j2eeJDBCStateChange: A JDBC driver or data source entered RUNNING, STOPPED, or FAILED state.
j2eeJCAStateChange: A JCA connection factory or managed connection factory entered RUNNING, STOPPED, or FAILED state
Since JBoss has not completely implemented, the event provider in the 3.x application server as per the JSR-77 specification, the traps cannot be emitted for the notifications defined in the JSR-77 MIB. Hence few rules are predefined by AdventNet to monitor the state change of the J2EE resource and the J2EE entity bean. The state change of entity bean cannot be monitored as the state manageable is not implemented for it.
State management refers to the management facilities that are provided by compliant J2EE platforms to manage the state of a J2EE platform and the components that comprise it. The management facilities allow Management Applications to get the current state of the platform and its components.
Performance monitoring is a StatisticProvider model which specifies the requirements of managed objects that provide performance data. The following are the j2eestatistics groups exposed in the JSR-77 J2EE MIB:
j2eeServletStatGroup: This group provides statistics for the servlets.
j2eeEjbStatGroup: This group provides statistics for the different types of EJBs.
j2eeJavaMailStatGroup: This group provides statistics for JavaMail resources.
j2eeJtaStatGroup: This group provides statistics for JTA resources.
j2eeJcaStatGroup: This group provides statistics of the non-pooled connections and the connection pools associated with the referencing JCA resource, connection factory.
j2eeJdbcStatGroup: This group provides statistics of the non-pooled connections and the connection pools associated with the referencing JDBC resource, connection factory.
j2eeJmsStatGroup: This group provides statistics for JMS connection session, JMS producer, and JMS consumer.
j2eeJvmStatGroup: This group provides statistics for JVM.
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