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WebLogic SNMP Management Guide


WebLogic Trap Notifications

You can configure the WebLogic SNMP agent to detect certain thresholds or conditions within a managed resource and send a report (trap notification) to one or more SNMP managers. The WebLogic SNMP agent can generate traps that conform to the SNMPv1 or SNMPv2 protocols.

The following sections describe the trap notifications that the WebLogic SNMP agent can generate:

For information on configuring or deleting WebLogic Server trap notifications, refer to "Configuring SNMP and WebLogic Server" in the Administration Console Online Help.

To see an example of using the weblogic.Admin utility to configure trap notifications, refer to "Using BATCHUPDATE to Configure the WebLogic SNMP Agent" in the WebLogic Server Command Reference.


Format of WebLogic Trap Notifications

The WebLogic SNMP agent sends each trap notification to SNMP managers in the form of a protocol data unit (PDU) with the fields indicated in Figure 2-1.

Figure 2-1 SNMP Trap Packet

SNMP Trap Packet


The fields have the following meaning:


Automatically Generated WebLogic SNMP Traps

If you enable the SNMP service for a domain, the WebLogic SNMP agent generates the trap notifications described in Table 2-3. Some of these traps include name/value pairs in the PDU to further describe the event.

Table 2-3 Automatically Generated Trap Notifications


Generated When

Variable Bindings


The Administration Server starts.



An SNMP manager sends an incorrect community string. The community string prefix is the actual password and must match the value that you set in the Community Prefix field of the Administration Console. (See SNMP Community Names.)



A WebLogic Managed Server that was down is now up.

Contains two name/value pairs to identify server start time and the server name.


A Managed Server that was up is now down.

Contains two name/value pairs to identify server down time and the server name.



Log Message Traps

Subsystems and deployable modules (such as applications) on a WebLogic Server instance generate log messages to communicate status or other operational data.

Each server instance saves these messages in a local log file and then broadcasts them as JMX notifications. You can set up the WebLogic SNMP agent to listen for all of these messages or you can set up a filter based on criteria such as the following:

For example, you can specify that only messages from the Security Service of severity level ERROR or higher are sent to the SNMP agent. For information on setting up the SNMP agent to listen for messages, refer to "Create a Notification Log Filter in the Administration Console Online Help.

When the agent receives a message, it generates an SNMP log notification trap. (See Figure 2-2.)

Figure 2-2 Log Message Traps

 Log Message Traps


Variable Bindings in Log Message Traps

This section describes the name/value pairs that the log message traps pass to the SNMP manager in the variable bindings field:

For more information on log messages and the WebLogic Server logging subsystem, refer to "Server Log" in the Administration Console Online Help.


Monitor Traps

To periodically check the value of WebLogic resources for changes, you set up monitors and assign them to instances of WebLogic Server. The monitors poll the MBeans of WebLogic resources at a specified interval and send notifications to the WebLogic SNMP agent when an event that you specify occurs, such as the crossing of a threshold. The SNMP agent generates a trap notification and sends it to the SNMP managers. (See Figure 2-3.)

Figure 2-3 Monitor Traps

Monitor Traps


If you are unfamiliar with WebLogic Server MBeans, refer to "Overview of WebLogic JMX Services" in the Programming WebLogic Management Services with JMX guide.

You can configure three types of JMX monitors, depending on the data type of the attribute that you want to observe (the MBean Javadoc describes the type of data that its attributes return):

Variable Bindings in Monitor Traps

A JMX monitor polls for a specified threshold or condition and the agent generates a monitor trap when the specified threshold is crossed, or the specified condition occurs. The WebLogic SNMP agent includes the following name/value pairs in the variable bindings of each monitor trap:


Attribute Change Traps

While you can use JMX monitors to periodically poll WebLogic Server resources for changes to attributes that exceed the bounds of specific thresholds, you can also configure the SNMP agent to send a trap immediately after an attribute is changed in any way. For example, you can use a monitor to poll for changes in the current number of active JDBC pools. If the number of active pools exceeds a threshold, the SNMP agent can send a trap. You would use an attribute change trap to detect whether an attribute such as the name of a JDBC pool or the listen port has been changed.

For information on configuring the SNMP agent to send attribute change traps, refer to "Configuring an Attribute Change" in the Administration Console Online Help.

Variable Bindings in Attribute Change Traps

An attribute change trap notification includes the following name/value pairs in the variable bindings:

Note: Creation of monitors for changes in run-time attributes is not supported. Only attributes in the configuration MIB can be monitored for change of attribute value.


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