Monitoring Services

The broker includes components for monitoring and diagnosing application and broker performance. These include the following:

• Components that generate data, a metrics generator and broker code that logs events.

• A logger component that writes out information to a number of output channels.

• A message producer that sends JMS messages containing metric information to topic destinations for consumption by JMS monitoring clients.

The general scheme is illustrated in Figure 3–4.

Figure 3–4 Monitoring Service Support

Metrics Generator

The metrics generator provides information about broker activity, such as message flow in and out of the broker, the number of messages in broker memory and the memory they consume, the number of open connections, and the number of threads being used.

You can set broker properties to turn the generation of metric data on and off, and to specify how frequently metrics reports are generated.

Logger

The Message Queue logger takes information generated by broker code and the metrics generator and writes that information to standard output (the console), to a log file, and, on Solaris^TM platforms, to the syslog daemon process in case of errors.

You can set broker properties to specify the type of information gathered by the logger as well as the type written to each of the output channels. In the case of a log file, you can also specify the point at which the log file is closed and output is rolled over to a new file. Once the log file reaches a specified size or age, it is saved and a new log file created.

For details about how to configure the logger and how to use it to obtain performance information, see Configuring and Using Broker Logging in Sun Java System Message Queue 3.7 UR1 Administration Guide.

Metrics Message Producer

The metrics message producer shown in Figure 3–4 receives information from the metrics generator at regular intervals and writes the information into messages, which it then sends to one of a number of metric topic destinations, depending on the type of metric information contained in the message.

Message Queue clients subscribed to these metric topic destinations can consume the messages and process the metric data contained in the messages. This allows developers to create custom monitoring tools to support messaging applications. For details of the metric quantities reported in each type of metrics message, see Chapter 18, Metrics Reference, in Sun Java System Message Queue 3.7 UR1 Administration Guide. For information about how to configure the production of metrics messages, see Chapter 4, Using the Metrics Monitoring API, in Sun Java System Message Queue 3.7 UR1 Developer’s Guide for Java Clients and Writing an Application to Monitor Brokers in Sun Java System Message Queue 3.7 UR1 Administration Guide.