Chapter 4. Monitoring broker runtime metrics

Procedure

1. Copy the Prometheus metrics plugin .jar file from your AMQ Broker 7.8 extracted archive to the lib directory of your broker instance.

   $ cp amq-broker-7.8.0/lib/artemis-prometheus-metrics-plugin-1.0.0.CR1-redhat-00010.jar <broker-instance-dir>/lib

2. Open the <broker-instance-dir>/etc/broker.xml configuration file.

3. Enable the Prometheus plugin in the broker configuration. Add a <metrics> element with a <plugin> sub-element, configured as shown below.

   <metrics>
       <plugin class-name="org.apache.activemq.artemis.core.server.metrics.plugins.ArtemisPrometheusMetricsPlugin"/>
   </metrics>

4. Save the broker.xml configuration file. The metrics plugin starts to gather broker runtime metrics in Prometheus format.

Procedure

1. Open the <broker-instance-dir>/etc/broker.xml configuration file.

2. In the <metrics> element that you added to the configuration when enabling the Prometheus metrics plugin, specify whether the broker collects JVM metrics for Garbage Collection (GC), memory, and threads. For example:

   <metrics>
       <jvm-gc>true</jvm-gc>
       <jvm-memory>true</jvm-memory
       <jvm-threads>true</jvm-threads>
       <plugin class-name="org.apache.activemq.artemis.core.server.metrics.plugins.ArtemisPrometheusMetricsPlugin"/>
   </metrics>

   Note

   If you do not explicitly add the jvm-memory parameter to your configuration and specify a value, the broker uses a default value of true. This means that the broker exports JVM memory metrics by default. The default values of the jvm-gc and jvm-threads parameters are false.

3. Save the broker.xml configuration file. The broker starts to gather the JVM metrics that you have enabled. These metrics are also exported to Prometheus format.

Procedure

1. Open the <broker-instance-dir>/etc/broker.xml configuration file.

2. In the address-setting element of a matching address or set of addresses, add the enable-metrics parameter and set the value of the parameter to false. For example, the following configuration disables metrics collection for an address called orders.

   <configuration>
     <core>
       ...
       <address-settings>
          <address-setting match="orders">
             ...
             <enable-metrics>false</enable-metrics>
             ...
          </address-setting>
       </address-settings>
       ...
     </core>
   </configuration>

Procedure

1. From your Prometheus installation directory, open the prometheus.yml configuration file.
2. In the static_configs section of the configuration file, change the targets element to localhost:8161. This location is where the broker runs its web server. By default, /metrics is appended to this host name, forming the full path to the metrics stored on the broker web server.

3. To view the broker runtime metrics collected by the Prometheus plugin, open localhost:8161/metrics in a web browser.

   On the resulting web page, you see the current values of the metrics collected by the plugin, based on the queues and addresses that you have configured on the broker. If you have more than one running broker instance in your JVM, you see metrics for each broker.

4. From your Prometheus installation directory, run Prometheus.

   $ ./prometheus

   When Prometheus starts, the shell output includes the following line:

   component=web, msg=”Start listening for connections” address=0.0.0.0:9090

   The preceding line indicates that Prometheus is listening for HTTP traffic on port 9090.

5. To access the Prometheus web console, open 127.0.0.1:9090 in a web browser.

6. In the Prometheus web console, you can use the Expression field to create a query on your broker data. The queries you create are based on the Prometheus query language, PromQL. Broker metrics that are available to insert in your query are in the Insert metric drop-down list.

   As a simple example, suppose you want to query the message count on the DLQ queue, over time. In this case, select artemis_message_count from the metrics drop-down list. Complete your query by specifying the DLQ queue name and address. This example query is shown below.

   artemis_message_count{address=“DLQ”, queue=“DLQ”}

   For more advanced visualizations, you can use regular expressions to create complex queries that overlay several metrics, for example. Or, you can perform mathematical operations on a number of metrics, such as aggregating them. For more information about creating Prometheus queries, see Querying Prometheus in the Prometheus documentation.