Chapter 180. JMX Component

By default, JMX instrumentation agent is enabled in Camel, which means that Camel runtime creates and registers MBean management objects with a MBeanServer instance in the VM. This allows Camel users to instantly obtain insights into how Camel routes perform down to the individual processor level.

The supported types of management objects are endpoint, route, service, and processor. Some of these management objects also expose lifecycle operations in addition to performance counter attributes.

The DefaultManagementNamingStrategy is the default naming strategy which builds object names used for MBean registration. By default, org.apache.camel is the domain name for all object names created by CamelNamingStrategy. The domain name of the MBean object can be configured by Java VM system property:

-Dorg.apache.camel.jmx.mbeanObjectDomainName=your.domain.name

Or, by adding a jmxAgent element inside the camelContext element in Spring configuration:

<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
  <jmxAgent id="agent" mbeanObjectDomainName="your.domain.name"/>
    ...
</camelContext>

Spring configuration always takes precedence over system properties when they both present. It is true for all JMX related configurations.

You can disable JMX instrumentation agent by setting the Java VM system property as follow:

-Dorg.apache.camel.jmx.disabled=true

The property value is treated as boolean.

Or, by adding a jmxAgent element inside the camelContext element in Spring configuration:

<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
  <jmxAgent id="agent" disabled="true"/>
    ...
</camelContext>

Or in Camel 2.1 its a bit easier (not having to use JVM system property) if using pure Java as you can disable it as follows:

CamelContext camel = new DefaultCamelContext();
camel.disableJMX();

Each CamelContext can have an instance of InstrumentationAgent wrapped inside the InstrumentationLifecycleStrategy. The InstrumentationAgent is the object that interfaces with a MBeanServer to register / unregister Camel MBeans. Multiple CamelContexts / InstrumentationAgents can / should share a MBeanServer. By default, Camel runtime picks the first MBeanServer returned by MBeanServerFactory.findMBeanServer method that matches the default domain name of org.apache.camel.

You may want to change the default domain name to match the MBeanServer instance that you are already using in your application. Especially, if your MBeanServer is attached to a JMX connector server, you will not need to create a connector server in Camel.

You can configure the matching default domain name via system property.

-Dorg.apache.camel.jmx.mbeanServerDefaultDomain=<your.domain.name>

Or, by adding a jmxAgent element inside the camelContext element in Spring configuration:

<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
  <jmxAgent id="agent" mbeanServerDefaultDomain="your.domain.name"/>
    ...
</camelContext>

If no matching MBeanServer can be found, a new one is created and the new `MBeanServer’s default domain name is set according to the default and configuration as mentioned above.

It is also possible to use the PlatformMBeanServer when it is desirable to manage JVM MBeans by setting the system property. The MBeanServer default domain name configuration is ignored as it is not applicable.

-Dorg.apache.camel.jmx.usePlatformMBeanServer=True

Or, by adding a jmxAgent element inside the camelContext element in Spring configuration:

<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
  <jmxAgent id="agent" usePlatformMBeanServer="true"/>
    ...
</camelContext>

See more system properties in this section below: jmxAgent Properties Reference.

JMX in the JDK have features for authentication and also for using secure connections over SSL. You have to refer to the SUN documentation how to use this:

The Spring configuration file allows you to configure how Camel is exposed to JMX for management. In some cases, you could specify more information here, like the connector’s port or the path name.

<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
  <jmxAgent id="agent" createConnector="true" registryPort="2000" mbeanServerDefaultDomain="org.apache.camel.test"/>
    <route>
      <from uri="seda:start"/>
      <to uri="mock:result"/>
    </route>
</camelContext>

If you wish to change the Java 5 JMX settings you can use various JMX system properties

For example you can enable remote JMX connections to the Sun JMX connector, via setting the following environment variable (using set or export depending on your platform). These settings only configure the Sun JMX connector within Java 1.5+, not the JMX connector that Camel creates by default.

SUNJMX=-Dcom.sun.management.jmxremote=true -Dcom.sun.management.jmxremote.port=1616 \
-Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false

(The SUNJMX environment variable is simple used by the startup script for Camel, as additional startup parameters for the JVM. If you start Camel directly, you’ll have to pass these parameters yourself.)

Available as of Camel 2.7

Camel now offers 2 settings to control whether or not to register mbeans

By default Camel registers MBeans for all the routes configured when its starting. The registerNewRoutes option control if MBeans should also be registered if you add new routes thereafter. You can disable this, if you for example add and remove temporary routes where management is not needed.

Be a bit caution to use the registerAlways option when using dynamic EIP patterns such as the Recipient List having unique endpoints. If so then each unique endpoint and its associated services/producers would also be registered. This could potential lead to system degration due the rising number of mbeans in the registry. A MBean is not a light-weight object and thus consumes memory.

The CamelContext should appear in the list of local connections, if you are running JConsole on the same host as Camel.

To connect to a remote Camel instance, or if the local process does not show up, use Remote Process option, and enter an URL. Here is an example localhost URL:service:jmx:rmi:///jndi/rmi://localhost:1099/jmxrmi/camel.

Using the Apache Camel with JConsole:

In Camel 2.1 onwards only singleton endpoints are registered as the overhead for non singleton will be substantial in cases where thousands or millions of endpoints are used. This can happens when using a Recipient List EIP or from a ProducerTemplate that sends a lot of messages.

See this FAQ.

The Camel notification events give a coarse grained overview what is happening. You can see lifecycle event from context and endpoints and you can see exchanges being received by and sent to endpoints.

From Camel 2.4 you can use a custom JMX NotificationListener to listen the camel events.

First you need to set up a JmxNotificationEventNotifier before you start the CamelContext:

// Set up the JmxNotificationEventNotifier
notifier = new JmxNotificationEventNotifier();
notifier.setSource("MyCamel");
notifier.setIgnoreCamelContextEvents(true);
notifier.setIgnoreRouteEvents(true);
notifier.setIgnoreServiceEvents(true);

CamelContext context = new DefaultCamelContext(createRegistry());
context.getManagementStrategy().addEventNotifier(notifier);

Second you can register your listener for listening the event:

// register the NotificationListener
ObjectName on = ObjectName.getInstance("org.apache.camel:context=camel-1,type=eventnotifiers,name=JmxEventNotifier");
MyNotificationListener listener = new MyNotificationListener();
context.getManagementStrategy().getManagementAgent().getMBeanServer().addNotificationListener(on,
    listener,
    new NotificationFilter() {
        private static final long serialVersionUID = 1L;

        public boolean isNotificationEnabled(Notification notification) {
            return notification.getSource().equals("MyCamel");
        }
    }, null);

Additionally to the coarse grained notifications above Camel 2.9.0 support JMX Notification for fine grained trace events.

These can be found in the Tracer MBean. To activate fine grained tracing you first need to activate tracing on the context or on a route.

This can either be done when configuring the context or on the context / route MBeans.

As a second step you have to set the jmxTraceNotifications attribute to true on the tracer. This can again be done when configuring the context or at runtime on the tracer MBean.

Now you can register for TraceEvent Notifications on the Tracer MBean using JConsole. There will be one Notification for every step on the route with all exchange and message details:

Available as of Camel 2.0
You can decorate your own endpoints with Spring managed annotations @ManagedResource to allow to register them in the Camel MBeanServer and thus access your custom MBeans using JMX.

For example we have the following custom endpoint where we define some options to be managed:

@ManagedResource(description = "Our custom managed endpoint")
public class CustomEndpoint extends MockEndpoint implements ManagementAware<CustomEndpoint> {

    public CustomEndpoint(final String endpointUri, final Component component) {
        super(endpointUri, component);
    }

    public Object getManagedObject(CustomEndpoint object) {
        return this;
    }

    public boolean isSingleton() {
        return true;
    }

    protected String createEndpointUri() {
        return "custom";
    }

    @ManagedAttribute
    public String getFoo() {
        return "bar";
    }

    @ManagedAttribute
    public String getEndpointUri() {
        return super.getEndpointUri();
    }
}

Notice from Camel 2.9 onwards its encouraged to use the @ManagedResource, @ManagedAttribute, and @ManagedOperation from the org.apache.camel.api.management package. This allows your custom code to not depend on Spring JARs.

Available as of Camel 2.1

Camel now offers to use your own MBeans when registering services for management. What that means is for example you can develop a custom Camel component and have it expose MBeans for endpoints, consumers and producers etc. All you need to do is to implement the interface org.apache.camel.spi.ManagementAware and return the managed object Camel should use.

Now before you think oh boys the JMX API is really painful and terrible, then yeah you are right. Lucky for us Spring though too and they created a range of annotations you can use to export management on an existing bean. That means that you often use that and just return this in the getManagedObject from the ManagementAware interface. For an example see the code example above with the CustomEndpoint.

Now in Camel 2.1 you can do this for all the objects that Camel registers for management which are quite a bunch, but not all.

For services which do not implement this ManagementAware interface then Camel will fallback to using default wrappers as defined in the table below:

In addition to that there are some extended wrappers for specialized types such as:

And in the future we will add additional wrappers for more EIP patterns.

Available as of Camel 2.1

Camel provides a pluggable API for naming strategy by org.apache.camel.spi.ManagementNamingStrategy. A default implementation is used to compute the MBean names that all MBeans are registered with.

Available as of Camel 2.10

From Camel 2.10 onwards we made it easier to configure a naming pattern for the MBeans. The pattern is used as part of the ObjectName as they key after the domain name.

By default Camel will use MBean names for the ManagedCamelContextMBean as follows:

org.apache.camel:context=localhost/camel-1,type=context,name=camel-1

And from Camel 2.13 onwards the hostname is not included in the MBean names, so the above example would be as follows:

org.apache.camel:context=camel-1,type=context,name=camel-1

If you configure a name on the CamelContext then that name is part of the ObjectName as well. For example if we have

<camelContext id="myCamel" ...>

Then the MBean names will be as follows:

org.apache.camel:context=localhost/myCamel,type=context,name=myCamel

Now if there is a naming clash in the JVM, such as there already exists a MBean with that given name above, then Camel will by default try to auto correct this by finding a new free name in the JMXMBeanServer by using a counter. As shown below the counter is now appended, so we have myCamel-1 as part of the ObjectName:

org.apache.camel:context=localhost/myCamel-1,type=context,name=myCamel

This is possible because Camel uses a naming pattern by default that supports the following tokens:

The default naming pattern is differentiated between OSGi and non-OSGi as follows:

However if there is a naming clash in the JMXMBeanServer then Camel will automatic fallback and use the counter in the pattern to remedy this. And thus the following patterns will then be used:

If you set an explicit naming pattern, then that pattern is always used, and the default patterns above is not used.

This allows us to have full control, very easily, of the naming for both the CamelContext id in the Registry as well the JMX MBeans in the JMXMBeanRegistry.

From Camel 2.15 onwards you can configure the default management name pattern using a JVM system property, to configure this globally for the JVM. Notice that you can override this pattern by configure it explicit, as shown in the examples further below.

Set a JVM system property to use a default management name pattern that prefixes the name with cool.

System.setProperty(JmxSystemPropertyKeys.MANAGEMENT_NAME_PATTERN, "cool-#name#");

So if we want to explicit name both the CamelContext and to use fixed MBean names, that do not change (eg has no counters), then we can use the new managementNamePattern attribute:

<camelContext id="myCamel" managementNamePattern="#name#">

Then the MBean names will always be as follows:

org.apache.camel:context=localhost/myCamel,type=context,name=myCamel

In Java, you can configure the managementNamePattern as follows:

context.getManagementNameStrategy().setNamePattern("#name#");

You can also use a different name in the managementNamePattern than the id, so for example we can do:

<camelContext id="myCamel" managementNamePattern="coolCamel">

You may want to do this in OSGi environments in case you do not want the OSGi bundle id as part of the MBean names. As the OSGi bundle id can change if you restart the server, or uninstall and install the same application. You can then do as follows to not use the OSGi bundle id as part of the name:

<camelContext id="myCamel" managementNamePattern="#name#">

Note this requires that myCamel is unique in the entire JVM. If you install a 2nd Camel application that has the same CamelContext id and managementNamePattern then Camel will fail upon starting, and report a MBean already exists exception.

Available as of Camel 2.1

Camel now provides a totally pluggable management strategy that allows you to be 100% in control of management. It is a rich interface with many methods for management. Not only for adding and removing managed objects from the MBeanServer, but also event notification is provided as well using the org.apache.camel.spi.EventNotifier API. What it does, for example, is make it easier to provide an adapter for other management products. In addition, it also allows you to provide more details and features that are provided out of the box at Apache.

Available as of Camel 2.1

You can now set a pre set level whether performance statistics is enabled or not when Camel start ups. The levels are

From Camel 2.9 onwards the performance statistics also include average load statistics per CamelContext and Route MBeans. The statistics is average load based on the number of in-flight exchanges, on a per 1, 5, and 15 minute rate. This is similar to load statistics on Unix systems. Camel 2.11 onwards allows you to explicit disable load performance statistics by setting loadStatisticsEnabled=false on the <jmxAgent>. Note that it will be off if the statics level is configured to off as well. From Camel 2.13 onwards the load performance statistics is by default disabled. You can enable this by setting loadStatisticsEnabled=true on the <jmxAgent>.

At runtime you can always use the management console (such as JConsole) to change on a given route or processor whether its statistics are enabled or not.

Using Java DSL you set this level by:

// only enable routes when Camel starts
context.getManagementStrategy().setStatisticsLevel(ManagementStatisticsLevel.RoutesOnly);

And from Spring DSL you do:

<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
    <jmxAgent id="agent" statisticsLevel="RoutesOnly"/>
 ...
</camelContext>

On the org.apache.camel.api.management.ManagedAttribute and org.apache.camel.api.management.ManagedOperation, the attribute mask can be set to true to indicate that the result of this JMX attribute/operation should be masked (if enabled on JMX agent, see above).

For example, on the default managed endpoints from camel-core org.apache.camel.api.management.mbean.ManagedEndpointMBean, we have declared that the EndpointUri JMX attribute is masked:

@ManagedAttribute(description = "Endpoint URI", mask = true)
String getEndpointUri();