Management

Apache ActiveMQ Artemis has an extensive management API that allows a user to modify a server configuration, create new resources (e.g. addresses and queues), inspect these resources (e.g. how many messages are currently held in a queue) and interact with it (e.g. to remove messages from a queue). All the operations allows a client to manage Apache ActiveMQ Artemis. It also allows clients to subscribe to management notifications.

There are 3 ways to manage Apache ActiveMQ Artemis:

  • Using JMX -- JMX is the standard way to manage Java applications

  • Using the core API -- management operations are sent to Apache ActiveMQ Artemis server using core messages

  • Using the JMS API -- management operations are sent to Apache ActiveMQ Artemis server using JMS messages

Although there are 3 different ways to manage Apache ActiveMQ Artemis each API supports the same functionality. If it is possible to manage a resource using JMX it is also possible to achieve the same result using Core.

This choice depends on your requirements, your application settings and your environment to decide which way suits you best.

In version 2 of Apache ActiveMQ Artemis the syntax used for MBean Object names has changed significantly due to changes in the addressing scheme. See the documentation for each individual resource for details on the new sytanx.

The Management API

Regardless of the way you invoke management operations, the management API is the same.

For each managed resource, there exists a Java interface describing what can be invoked for this type of resource.

Apache ActiveMQ Artemis exposes its managed resources in the org.apache.activemq.artemis.api.core.management package

The way to invoke a management operations depends whether JMX, core messages, or JMS messages are used.

Note

A few management operations requires a filter parameter to chose which messages are involved by the operation. Passing null or an empty string means that the management operation will be performed on all messages.

Apache ActiveMQ Artemis Management API

Apache ActiveMQ Artemis defines a core management API to manage core resources. For full details of the API please consult the javadoc. In summary:

Apache ActiveMQ Artemis Server Management

  • Listing, creating, deploying and destroying queues

    A list of deployed core queues can be retrieved using the getQueueNames() method.

    Core queues can be created or destroyed using the management operations createQueue() or deployQueue() or destroyQueue())on the ActiveMQServerControl (with the ObjectName org.apache.activemq.artemis:broker="<brokerName>" or the resource name broker)

    createQueue will fail if the queue already exists while deployQueue will do nothing.

  • Pausing and resuming Queues

    The QueueControl can pause and resume the underlying queue. When a queue is paused, it will receive messages but will not deliver them. When it's resumed, it'll begin delivering the queued messages, if any.

  • Listing and closing remote connections

    Client's remote addresses can be retrieved using listRemoteAddresses(). It is also possible to close the connections associated with a remote address using the closeConnectionsForAddress() method.

    Alternatively, connection IDs can be listed using listConnectionIDs() and all the sessions for a given connection ID can be listed using listSessions().

  • Transaction heuristic operations

    In case of a server crash, when the server restarts, it it possible that some transaction requires manual intervention. The listPreparedTransactions() method lists the transactions which are in the prepared states (the transactions are represented as opaque Base64 Strings.) To commit or rollback a given prepared transaction, the commitPreparedTransaction() or rollbackPreparedTransaction() method can be used to resolve heuristic transactions. Heuristically completed transactions can be listed using the listHeuristicCommittedTransactions() and listHeuristicRolledBackTransactions methods.

  • Enabling and resetting Message counters

    Message counters can be enabled or disabled using the enableMessageCounters() or disableMessageCounters() method. To reset message counters, it is possible to invoke resetAllMessageCounters() and resetAllMessageCounterHistories() methods.

  • Retrieving the server configuration and attributes

    The ActiveMQServerControl exposes Apache ActiveMQ Artemis server configuration through all its attributes (e.g. getVersion() method to retrieve the server's version, etc.)

  • Listing, creating and destroying Core bridges and diverts

    A list of deployed core bridges (resp. diverts) can be retrieved using the getBridgeNames() (resp. getDivertNames()) method.

    Core bridges (resp. diverts) can be created or destroyed using the management operations createBridge() and destroyBridge() (resp. createDivert() and destroyDivert()) on the ActiveMQServerControl (with the ObjectName org.apache.activemq.artemis:broker="<brokerName>" or the resource name broker).

  • It is possible to stop the server and force failover to occur with any currently attached clients.

    to do this use the forceFailover() on the ActiveMQServerControl (with the ObjectName org.apache.activemq.artemis:broker="<brokerName>" or the resource name broker)

    Note

    Since this method actually stops the server you will probably receive some sort of error depending on which management service you use to call it.

Address Management

Core addresses can be managed using the AddressControl class (with the ObjectName org.apache.activemq.artemis:broker="<brokerName>",component=addresses,address="<addressName>" or the resource name address.<addressName>).

  • Modifying roles and permissions for an address

    You can add or remove roles associated to a queue using the addRole() or removeRole() methods. You can list all the roles associated to the queue with the getRoles() method

Queue Management

The bulk of the core management API deals with core queues. The QueueControl class defines the Core queue management operations (with the ObjectName org.apache.activemq.artemis:broker="<brokerName>",component=addresses,address="<addressName>",subcomponent=queues,routing-type="<routingType>",queue="<queueName>" or the resource name queue.<queueName>).

Most of the management operations on queues take either a single message ID (e.g. to remove a single message) or a filter (e.g. to expire all messages with a given property.)

  • Expiring, sending to a dead letter address and moving messages

    Messages can be expired from a queue by using the expireMessages() method. If an expiry address is defined, messages will be sent to it, otherwise they are discarded. The queue's expiry address can be set with the setExpiryAddress() method.

    Messages can also be sent to a dead letter address with the sendMessagesToDeadLetterAddress() method. It returns the number of messages which are sent to the dead letter address. If a dead letter address is not defined, message are removed from the queue and discarded. The queue's dead letter address can be set with the setDeadLetterAddress() method.

    Messages can also be moved from a queue to another queue by using the moveMessages() method.

  • Listing and removing messages

    Messages can be listed from a queue by using the listMessages() method which returns an array of Map, one Map for each message.

    Messages can also be removed from the queue by using the removeMessages() method which returns a boolean for the single message ID variant or the number of removed messages for the filter variant. The removeMessages() method takes a filter argument to remove only filtered messages. Setting the filter to an empty string will in effect remove all messages.

  • Counting messages

    The number of messages in a queue is returned by the getMessageCount() method. Alternatively, the countMessages() will return the number of messages in the queue which match a given filter

  • Changing message priority

    The message priority can be changed by using the changeMessagesPriority() method which returns a boolean for the single message ID variant or the number of updated messages for the filter variant.

  • Message counters

    Message counters can be listed for a queue with the listMessageCounter() and listMessageCounterHistory() methods (see Message Counters section). The message counters can also be reset for a single queue using the resetMessageCounter() method.

  • Retrieving the queue attributes

    The QueueControl exposes queue settings through its attributes (e.g. getFilter() to retrieve the queue's filter if it was created with one, isDurable() to know whether the queue is durable or not, etc.)

  • Pausing and resuming Queues

    The QueueControl can pause and resume the underlying queue. When a queue is paused, it will receive messages but will not deliver them. When it's resume, it'll begin delivering the queued messages, if any.

Other Resources Management

Apache ActiveMQ Artemis allows to start and stop its remote resources (acceptors, diverts, bridges, etc.) so that a server can be taken off line for a given period of time without stopping it completely (e.g. if other management operations must be performed such as resolving heuristic transactions). These resources are:

  • Acceptors

    They can be started or stopped using the start() or. stop() method on the AcceptorControl class (with the ObjectName org.apache.activemq.artemis:broker="<brokerName>",component=acceptor,name="<acceptorName>" or the resource name acceptor.<acceptorName>). The acceptors parameters can be retrieved using the AcceptorControl attributes (see Understanding Acceptors)

  • Diverts

    They can be started or stopped using the start() or stop() method on the DivertControl class (with the ObjectName org.apache.activemq.artemis:broker="<brokerName>",component=addresses,address="<addressName>",subcomponent=diverts,divert="<divertName>" or the resource name divert.<divertName>). Diverts parameters can be retrieved using the DivertControl attributes (see Diverting and Splitting Message Flows))

  • Bridges

    They can be started or stopped using the start() (resp. stop()) method on the BridgeControl class (with the ObjectName org.apache.activemq.artemis:broker="<brokerName>",component=bridges,name="<bridgeName>" or the resource name bridge.<the bridge name>). Bridges parameters can be retrieved using the BridgeControl attributes (see Core bridges)

  • Broadcast groups

    They can be started or stopped using the start() or stop() method on the BroadcastGroupControl class (with the ObjectName org.apache.activemq.artemis:broker="<brokerName>",component=broadcast-groups,name="<broadcastgroupName>" or the resource name broadcastgroup.<the broadcast group name>). Broadcast groups parameters can be retrieved using the BroadcastGroupControl attributes (see Clusters)

  • Cluster connections

    They can be started or stopped using the start() or stop() method on the ClusterConnectionControl class (with the ObjectName org.apache.activemq.artemis:broker="<brokerName>",component=cluster-connections,name="<clusterconnectionName>" or the resource name clusterconnection.<the cluster connection name>). Cluster connections parameters can be retrieved using the ClusterConnectionControl attributes (see Clusters)

Using Management Via JMX

Apache ActiveMQ Artemis can be managed using JMX.

The management API is exposed by Apache ActiveMQ Artemis using MBeans interfaces. Apache ActiveMQ Artemis registers its resources with the domain org.apache.activemq.artemis.

For example, the ObjectName to manage the anycast queue exampleQueue on the address exampleAddress is:

org.apache.activemq.artemis:broker=<brokerName>,component=addresses,address="exampleAddress",subcomponent=queues,routing-type="anycast",queue="exampleQueue"

and the MBean is:

org.apache.activemq.artemis.api.core.management.QueueControl

The MBean's ObjectName are built using the helper class org.apache.activemq.artemis.api.core.management.ObjectNameBuilder. You can also use jconsole to find the ObjectName of the MBeans you want to manage.

Managing Apache ActiveMQ Artemis using JMX is identical to management of any Java Applications using JMX. It can be done by reflection or by creating proxies of the MBeans.

Configuring JMX

By default, JMX is enabled to manage Apache ActiveMQ Artemis. It can be disabled by setting jmx-management-enabled to false in broker.xml:

<!-- false to disable JMX management for Apache ActiveMQ Artemis -->
<jmx-management-enabled>false</jmx-management-enabled>

If JMX is enabled, Apache ActiveMQ Artemis can be managed locally using jconsole.

Note

Remote connections to JMX are not enabled by default for security reasons. Please refer to Java Management guide to configure the server for remote management (system properties must be set in artemis.profile).

By default, Apache ActiveMQ Artemis server uses the JMX domain "org.apache.activemq.artemis". To manage several Apache ActiveMQ Artemis servers from the same MBeanServer, the JMX domain can be configured for each individual Apache ActiveMQ Artemis server by setting jmx-domain in broker.xml:

<!-- use a specific JMX domain for ActiveMQ Artemis MBeans -->
<jmx-domain>my.org.apache.activemq</jmx-domain>

MBeanServer configuration

When Apache ActiveMQ Artemis is run in standalone, it uses the Java Virtual Machine's Platform MBeanServer to register its MBeans. By default Jolokia is also deployed to allow access to the mbean server via rest.

Example

See the chapters chapter for an example which shows how to use a remote connection to JMX and MBean proxies to manage Apache ActiveMQ Artemis.

Exposing JMX using Jolokia

The default Broker configuration ships with the Jolokia http agent deployed as a Web Application. Jolokia is a remote JMX over HTTP bridge that exposed mBeans, for a full guids as to how to use refer to Jolokia Documentation, however a simple example to query the broker's version would be to use a browser and go to the URL http://localhost:8161/jolokia/read/org.apache.activemq.artemis:broker="0.0.0.0"/Version.

This would give you back something like the following:

{"request":{"mbean":"org.apache.activemq.artemis:broker=\"0.0.0.0\"","attribute":"Version","type":"read"},"value":"2.0.0-SNAPSHOT","timestamp":1487017918,"status":200}

Using Management Via Apache ActiveMQ Artemis API

The management API in ActiveMQ Artemis is called by sending Core Client messages to a special address, the management address.

Management messages are regular Core Client messages with well-known properties that the server needs to understand to interact with the management API:

  • The name of the managed resource

  • The name of the management operation

  • The parameters of the management operation

When such a management message is sent to the management address, Apache ActiveMQ Artemis server will handle it, extract the information, invoke the operation on the managed resources and send a management reply to the management message's reply-to address (specified by ClientMessageImpl.REPLYTO_HEADER_NAME).

A ClientConsumer can be used to consume the management reply and retrieve the result of the operation (if any) stored in the reply's body. For portability, results are returned as a JSON String rather than Java Serialization (the org.apache.activemq.artemis.api.core.management.ManagementHelper can be used to convert the JSON string to Java objects).

These steps can be simplified to make it easier to invoke management operations using Core messages:

  1. Create a ClientRequestor to send messages to the management address and receive replies

  2. Create a ClientMessage

  3. Use the helper class org.apache.activemq.artemis.api.core.management.ManagementHelper to fill the message with the management properties

  4. Send the message using the ClientRequestor

  5. Use the helper class org.apache.activemq.artemis.api.core.management.ManagementHelper to retrieve the operation result from the management reply

For example, to find out the number of messages in the core queue exampleQueue:

ClientSession session = ...
ClientRequestor requestor = new ClientRequestor(session, "activemq.management");
ClientMessage message = session.createMessage(false);
ManagementHelper.putAttribute(message, "queue.exampleQueue", "messageCount");
session.start();
ClientMessage reply = requestor.request(m);
int count = (Integer) ManagementHelper.getResult(reply);
System.out.println("There are " + count + " messages in exampleQueue");

Management operation name and parameters must conform to the Java interfaces defined in the management packages.

Names of the resources are built using the helper class org.apache.activemq.artemis.api.core.management.ResourceNames and are straightforward (e.g. queue.exampleQueue for the Core Queue exampleQueue.

Configuring Management

The management address to send management messages is configured in broker.xml:

<management-address>activemq.management</management-address>

By default, the address is activemq.management.

The management address requires a special user permission manage to be able to receive and handle management messages. This is also configured in broker.xml:

<!-- users with the admin role will be allowed to manage -->
<!-- Apache ActiveMQ Artemis using management messages        -->
<security-setting match="activemq.management">
   <permission type="manage" roles="admin" />
</security-setting>

Example

See the examples chapter for an example which shows how to use JMS messages to manage the Apache ActiveMQ Artemis server.

Management Notifications

Apache ActiveMQ Artemis emits notifications to inform listeners of potentially interesting events (creation of new resources, security violation, etc.).

These notifications can be received by 3 different ways:

  • JMX notifications

  • Core messages

  • JMS messages

JMX Notifications

If JMX is enabled (see Configuring JMX section), JMX notifications can be received by subscribing to org.apache.activemq.artemis:type=Broker,brokerName=<broker name>,module=Core,serviceType=Server for notifications on resources.

Core Messages Notifications

Apache ActiveMQ Artemis defines a special management notification address. Core queues can be bound to this address so that clients will receive management notifications as Core messages

A Core client which wants to receive management notifications must create a core queue bound to the management notification address. It can then receive the notifications from its queue.

Notifications messages are regular core messages with additional properties corresponding to the notification (its type, when it occurred, the resources which were concerned, etc.).

Since notifications are regular core messages, it is possible to use message selectors to filter out notifications and receives only a subset of all the notifications emitted by the server.

Configuring The Core Management Notification Address

The management notification address to receive management notifications is configured in broker.xml:

<management-notification-address>activemq.notifications</management-notification-address>

By default, the address is activemq.notifications.

JMS Messages Notifications

Apache ActiveMQ Artemis's notifications can also be received using JMS messages.

It is similar to receiving notifications using Core API:

Topic notificationsTopic = ActiveMQJMSClient.createTopic("notificationsTopic");

Session session = ...
MessageConsumer notificationConsumer = session.createConsumer(notificationsTopic);
notificationConsumer.setMessageListener(new MessageListener()
{
   public void onMessage(Message notif)
   {
      System.out.println("------------------------");
      System.out.println("Received notification:");
      try
      {
         Enumeration propertyNames = notif.getPropertyNames();
         while (propertyNames.hasMoreElements())
         {
            String propertyName = (String)propertyNames.nextElement();
            System.out.format("  %s: %s\n", propertyName, notif.getObjectProperty(propertyName));
         }
      }
      catch (JMSException e)
      {
      }
      System.out.println("------------------------");
   }
});

Example

See the examples chapter for an example which shows how to use a JMS MessageListener to receive management notifications from ActiveMQ Artemis server.

Notification Types and Headers

Below is a list of all the different kinds of notifications as well as which headers are on the messages. Every notification has a _AMQ_NotifType (value noted in parentheses) and _AMQ_NotifTimestamp header. The timestamp is the un-formatted result of a call to java.lang.System.currentTimeMillis().

  • BINDING_ADDED (0)

    _AMQ_Binding_Type, _AMQ_Address, _AMQ_ClusterName, _AMQ_RoutingName, _AMQ_Binding_ID, _AMQ_Distance, _AMQ_FilterString

  • BINDING_REMOVED (1)

    _AMQ_Address, _AMQ_ClusterName, _AMQ_RoutingName, _AMQ_Binding_ID, _AMQ_Distance, _AMQ_FilterString

  • CONSUMER_CREATED (2)

    _AMQ_Address, _AMQ_ClusterName, _AMQ_RoutingName, _AMQ_Distance, _AMQ_ConsumerCount, _AMQ_User, _AMQ_RemoteAddress, _AMQ_SessionName, _AMQ_FilterString

  • CONSUMER_CLOSED (3)

    _AMQ_Address, _AMQ_ClusterName, _AMQ_RoutingName, _AMQ_Distance, _AMQ_ConsumerCount, _AMQ_User, _AMQ_RemoteAddress, _AMQ_SessionName, _AMQ_FilterString

  • SECURITY_AUTHENTICATION_VIOLATION (6)

    _AMQ_User

  • SECURITY_PERMISSION_VIOLATION (7)

    _AMQ_Address, _AMQ_CheckType, _AMQ_User

  • DISCOVERY_GROUP_STARTED (8)

    name

  • DISCOVERY_GROUP_STOPPED (9)

    name

  • BROADCAST_GROUP_STARTED (10)

    name

  • BROADCAST_GROUP_STOPPED (11)

    name

  • BRIDGE_STARTED (12)

    name

  • BRIDGE_STOPPED (13)

    name

  • CLUSTER_CONNECTION_STARTED (14)

    name

  • CLUSTER_CONNECTION_STOPPED (15)

    name

  • ACCEPTOR_STARTED (16)

    factory, id

  • ACCEPTOR_STOPPED (17)

    factory, id

  • PROPOSAL (18)

    _JBM_ProposalGroupId, _JBM_ProposalValue, _AMQ_Binding_Type, _AMQ_Address, _AMQ_Distance

  • PROPOSAL_RESPONSE (19)

    _JBM_ProposalGroupId, _JBM_ProposalValue, _JBM_ProposalAltValue, _AMQ_Binding_Type, _AMQ_Address, _AMQ_Distance

  • CONSUMER_SLOW (21)

    _AMQ_Address, _AMQ_ConsumerCount, _AMQ_RemoteAddress, _AMQ_ConnectionName, _AMQ_ConsumerName, _AMQ_SessionName

Message Counters

Message counters can be used to obtain information on queues over time as Apache ActiveMQ Artemis keeps a history on queue metrics.

They can be used to show trends on queues. For example, using the management API, it would be possible to query the number of messages in a queue at regular interval. However, this would not be enough to know if the queue is used: the number of messages can remain constant because nobody is sending or receiving messages from the queue or because there are as many messages sent to the queue than messages consumed from it. The number of messages in the queue remains the same in both cases but its use is widely different.

Message counters gives additional information about the queues:

  • count

    The total number of messages added to the queue since the server was started

  • countDelta

    the number of messages added to the queue since the last message counter update

  • messageCount

    The current number of messages in the queue

  • messageCountDelta

    The overall number of messages added/removed from the queue since the last message counter update. For example, if messageCountDelta is equal to -10 this means that overall 10 messages have been removed from the queue (e.g. 2 messages were added and 12 were removed)

  • lastAddTimestamp

    The timestamp of the last time a message was added to the queue

  • udpateTimestamp

    The timestamp of the last message counter update

These attributes can be used to determine other meaningful data as well. For example, to know specifically how many messages were consumed from the queue since the last update simply subtract the messageCountDelta from countDelta.

Configuring Message Counters

By default, message counters are disabled as it might have a small negative effect on memory.

To enable message counters, you can set it to true in broker.xml:

<message-counter-enabled>true</message-counter-enabled>

Message counters keeps a history of the queue metrics (10 days by default) and samples all the queues at regular interval (10 seconds by default). If message counters are enabled, these values should be configured to suit your messaging use case in broker.xml:

<!-- keep history for a week -->
<message-counter-max-day-history>7</message-counter-max-day-history>
<!-- sample the queues every minute (60000ms) -->
<message-counter-sample-period>60000</message-counter-sample-period>

Message counters can be retrieved using the Management API. For example, to retrieve message counters on a queue using JMX:

// retrieve a connection to Apache ActiveMQ Artemis's MBeanServer
MBeanServerConnection mbsc = ...
QueueControlMBean queueControl = (QueueControl)MBeanServerInvocationHandler.newProxyInstance(mbsc,
   on,
   QueueControl.class,
   false);
// message counters are retrieved as a JSON String
String counters = queueControl.listMessageCounter();
// use the MessageCounterInfo helper class to manipulate message counters more easily
MessageCounterInfo messageCounter = MessageCounterInfo.fromJSON(counters);
System.out.format("%s message(s) in the queue (since last sample: %s)\n",
messageCounter.getMessageCount(),
messageCounter.getMessageCountDelta());

Example

See the examples chapter for an example which shows how to use message counters to retrieve information on a JMS Queue.

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