Apache ActiveMQ Artemis is designed to allow extra functionality to be added by creating a plugin. Multiple plugins can be registered at the same time and they will be chained together and executed in the order they are registered (i.e. the first plugin registered is always executed first).
Creating a plugin is very simple. It requires:
Implementing the ActiveMQServerPlugin interface
Making sure the plugin is on the classpath
Registering it with the broker either via xml or programmatically.
Only the methods that you want to add behavior for need to be implemented as all of the interface methods are default methods.
1. Registering a Plugin
To register a plugin with by XML you need to add the broker-plugins
element at the broker.xml
. It is also possible to pass configuration to a plugin using the property
child element(s). These properties (zero to many) will be read and passed into the plugin’s init(Map<String, String>)
operation after the plugin has been instantiated.
<broker-plugins>
<broker-plugin class-name="some.plugin.UserPlugin">
<property key="property1" value="val_1" />
<property key="property2" value="val_2" />
</broker-plugin>
</broker-plugins>
2. Registering a Plugin Programmatically
For registering a plugin programmatically you need to call the registerBrokerPlugin()
method and pass in a new instance of your plugin. In the example below assuming your plugin is called UserPlugin
, registering it looks like the following:
...
Configuration config = new ConfigurationImpl();
...
config.registerBrokerPlugin(new UserPlugin());
3. Using the LoggingActiveMQServerPlugin
The LoggingActiveMQServerPlugin
logs specific broker events.
You can select which events are logged by setting the following configuration properties to true
.
Property | Trigger Event | Default Value |
---|---|---|
| Connection is created/destroy. |
|
| Session is created/closed. |
|
| Consumer is created/closed |
|
| Message is delivered to a consumer and when a message is acknowledged by a consumer. |
|
| When a message has been sent to an address and when a message has been routed within the broker. |
|
| When a queue created/destroyed, when a message is expired, when a bridge is deployed and when a critical failure occurs. |
|
| Includes all the above events. |
|
By default the LoggingActiveMQServerPlugin
will not log any information. The logging is activated by setting one (or a selection) of the above configuration properties to true
.
To configure the plugin, you can add the following configuration to the broker. In the example below both LOG_DELIVERING_EVENTS
and LOG_SENDING_EVENTS
will be logged by the broker.
<broker-plugins>
<broker-plugin class-name="org.apache.activemq.artemis.core.server.plugin.impl.LoggingActiveMQServerPlugin">
<property key="LOG_DELIVERING_EVENTS" value="true" />
<property key="LOG_SENDING_EVENTS" value="true" />
</broker-plugin>
</broker-plugins>
Most events in the LoggingActiveMQServerPlugin
follow a beforeX
and afterX
notification pattern (e.g beforeCreateConsumer()
and afterCreateConsumer()
).
At Log Level INFO
, the LoggingActiveMQServerPlugin logs an entry when an afterX
notification occurs. By setting the logger org.apache.activemq.artemis.core.server.plugin.impl
to DEBUG
, log entries are generated for both beforeX
and afterX
notifications. Log level DEBUG
will also log more information for a notification when available.
4. Using the NotificationActiveMQServerPlugin
The NotificationActiveMQServerPlugin can be configured to send extra notifications for specific broker events.
You can select which notifications are sent by setting the following configuration properties to true
.
Property | Property Description | Default Value |
---|---|---|
| Sends a notification when a Connection is created/destroy. |
|
| Sends a notification when a Session is created/closed. |
|
| Sends a notification when an Address is added/removed. |
|
| Sends a notification when message is delivered to a consumer. |
|
| Sends a notification when message has been expired by the broker. |
|
By default the NotificationActiveMQServerPlugin will not send any notifications. The plugin is activated by setting one (or a selection) of the above configuration properties to true
.
To configure the plugin, you can add the following configuration to the broker. In the example below both SEND_CONNECTION_NOTIFICATIONS
and SEND_SESSION_NOTIFICATIONS
will be sent by the broker.
<broker-plugins>
<broker-plugin class-name="org.apache.activemq.artemis.core.server.plugin.impl.NotificationActiveMQServerPlugin">
<property key="SEND_CONNECTION_NOTIFICATIONS" value="true" />
<property key="SEND_SESSION_NOTIFICATIONS" value="true" />
</broker-plugin>
</broker-plugins>
5. Using the BrokerMessageAuthorizationPlugin
The BrokerMessageAuthorizationPlugin
filters messages sent to consumers based on if they have a role that matches the value specified in a message property.
You can select which property will be used to specify the required role for consuming a message by setting the following configuration.
Property | Property Description | Default Value |
---|---|---|
| Property name used to determine the role required to consume a message. |
|
If the message does not have a property matching the configured ROLE_PROPERTY
then the message will be sent to any consumer.
To configure the plugin, you can add the following configuration to the broker. In the example below ROLE_PROPERTY
is set to permissions
when that property is present messages will only be sent to consumers with a role matching its value.
<broker-plugins>
<broker-plugin class-name="org.apache.activemq.artemis.core.server.plugin.impl.BrokerMessageAuthorizationPlugin">
<property key="ROLE_PROPERTY" value="permissions" />
</broker-plugin>
</broker-plugins>
6. Using the ConnectionPeriodicExpiryPlugin
The ConnectionPeriodicExpiryPlugin
will implement a global expiry (and disconnect) for connections that live longer than periodSeconds
on a matching acceptor basis.
This plugin can be useful when credential rotation or credential validation must be enforced at regular intervals as authentication will be enforced on reconnect.
The plugin requires the configuration of the acceptorMatchRegex
to determine the acceptors to monitor. It is typical to separate client acceptors and federation or cluster acceptors such that only client connections will be subject to periodic expiry. The acceptorMatchRegex
must be configured to match the name of the acceptor(s) whose connections will be subject to periodic expiry.
Property | Property Description | Default Value |
---|---|---|
| the regular expression used to match against the names of acceptors to monitor | |
| the max period, in seconds, that a connection can last | 900 seconds (15 minutes) |
| determines how often we check connections for expiry and also provides an upper bound on the random seconds we use to schedule a disconnect. Using a random second will potentially avoid many reconnects occurring at the exact same time. It must be positive value > 0 | 30 seconds |
The plugin can be configured via xml in the normal broker-plugin way:
<broker-plugins>
<broker-plugin class-name="org.apache.activemq.artemis.core.server.plugin.impl.ConnectionPeriodicExpiryPlugin">
<property key="acceptorMatchRegex" value="netty-client-acceptor" />
</broker-plugin>
</broker-plugins>