Sun Java System Message Queue 4.3 Developer's Guide for JMX Clients

Logging

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

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.


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.


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