Logging

This section describes the MBeans used for logging Message Queue operations:

• The log configuration MBean configures Message Queue logging.

• The log monitor MBean monitors Message Queue logging.

The following subsections describe each of these MBeans in detail.

Log Configuration

Each broker has a single log configuration MBean, used for configuring Message Queue logging.

Object Name

The log configuration MBean has the following object name:

com.sun.messaging.jms.server:type=Log,subtype=Config

A string representing this object name is defined as a static constant LOG_CONFIG_MBEAN_NAME in the utility class MQObjectName.

Attributes

The log configuration MBean has the attributes shown in Table 3–84. The names of these attributes are defined as static constants in the utility class LogAttributes.

Table 3–84 Log Configuration Attributes

Name	Type	Settable?	Description
Level	String	Yes	Logging level  Specifies the categories of logging information that can be written to an output channel. See Table 3–85 for possible values.
RolloverBytes	Long	Yes	File length, in bytes, at which output rolls over to a new log file  A value of -1 denotes an unlimited number of bytes (no rollover based on file length).
RolloverSecs	Long	Yes	Age of file, in seconds, at which output rolls over to a new log file  A value of -1 denotes an unlimited number of seconds (no rollover based on file age).

Table 3–85 shows the possible values for the Level attribute. Each level includes those above it (for example, WARNING includes ERROR). These values are defined as static constants in the utility class LogLevel.

Table 3–85 Log Configuration Logging Levels

Name	Utility Constant	Meaning
NONE	LogLevel.NONE	No logging
ERROR	LogLevel.ERROR	Log error messages
WARNING	LogLevel.WARNING	Log warning messages
INFO	LogLevel.INFO	Log informational messages
UNKNOWN	LogLevel.UNKNOWN	Logging level unknown

Notification

The log configuration MBean supports the notification shown in Table 3–86.

Table 3–86 Log Configuration Notification

Name	Description
jmx.attribute.change	Attribute value changed

Log Monitor

Each broker has a single log monitor MBean, used for monitoring Message Queue logging.

Object Name

The log monitor MBean has the following object name:

com.sun.messaging.jms.server:type=Log,subtype=Monitor

A string representing this object name is defined as a static constant LOG_MONITOR_MBEAN_NAME in the utility class MQObjectName.

Notifications

The log monitor MBean supports the notifications shown in Table 3–87. These notifications are instances of the Message Queue JMX class LogNotification, and their names are defined as static utility constants in that class.

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Note –

A notification listener registered for a particular logging level will receive notifications only for that level and not for those above or below it: for example, a listener registered for the notification mq.log.level.WARNING will be notified only of WARNING messages and not ERROR or INFO. To receive notifications for more than one logging level, the listener must be explicitly registered for each level separately.

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Table 3–87 Log Monitor Notifications

Name	Utility Constant	Description
mq.log.level.ERROR	LogNotification.LOG_LEVEL_ERROR	Error message logged
mq.log.level.WARNING	LogNotification.LOG_LEVEL_WARNING	Warning message logged
mq.log.level.INFO	LogNotification.LOG_LEVEL_INFO	Informational message logged

Table 3–88 shows the methods defined in class LogNotification for obtaining details about a log monitor notification.

Table 3–88 Data Retrieval Methods for Log Monitor Notifications

Method	Result Type	Description
getLevel	String	Logging level of logged message  See Table 3–85 for possible values.
getMessage	String	Body of logged message