# Addressing Model

Apache ActiveMQ Artemis has a unique addressing model that is both powerful and flexible and that offers great performance. The addressing model comprises three main concepts: addresses, queues, and routing types.

### Address

An address represents a messaging endpoint. Within the configuration, a typical address is given a unique name, 0 or more queues, and a routing type.

### Queue

A queue is associated with an address. There can be multiple queues per address. Once an incoming message is matched to an address, the message will be sent on to one or more of its queues, depending on the routing type configured. Queues can be configured to be automatically created and deleted.

### Routing Types

A routing type determines how messages are sent to the queues associated with an address. An Apache ActiveMQ Artemis address can be configured with two different routing types.

Table 1. Routing Types

If you want your messages routed to... | Use this routing type...
--- | ---
A single queue within the matching address, in a point-to-point manner. | Anycast
Every queue within the matching address, in a publish-subscribe manner. | Multicast

Note: It is possible to define more than one routing type per address, but this typically results in an anti-pattern and is therefore not recommended. If an address does use both routing types, however, and the client does not show a preference for either one, the broker typically defaults to the anycast routing type.

The one exception is when the client uses the MQTT protocol. In that case, the default routing type is multicast.

For additional details about these concepts refer to the core chapter.

## Basic Address Configuration

The following examples show how to configure basic point to point and publish subscribe addresses.

### Point-to-Point Messaging

Point-to-point messaging is a common scenario in which a message sent by a producer has only one consumer. AMQP and JMS message producers and consumers can make use of point-to-point messaging queues, for example. Define an anycast routing type for an address so that its queues receive messages in a point-to-point manner.

When a message is received on an address using anycast, Apache ActiveMQ Artemis locates the queue associated with the address and routes the message to it. When consumers request to consume from the address, the broker locates the relevant queue and associates this queue with the appropriate consumers. If multiple consumers are connected to the same queue, messages are distributed amongst each consumer equally, providing the consumers are equally able to handle them.

Figure 1. Point to Point Messaging

#### Using the Anycast Routing Type

Open the file `<broker-instance>/etc/broker.xml` for editing.

Add an address configuration element and its associated queue if they do not exist already.

Note: For normal Point to Point semantics, the queue name MUST match the address name.

    <addresses>
       <address name="orders">
          <anycast>
             <queue name="orders"/>
          </anycast>
       </address>
    </addresses>

### Publish-Subscribe Messaging

In a publish-subscribe scenario, messages are sent to every consumer subscribed to an address. JMS topics and MQTT subscriptions are two examples of publish-subscribe messaging.

To configure an address with publish-subscribe semantics, create an address with the multicast routing type.

Figure 2. Publish-Subscribe

#### Using the Multicast Routing Type

Open the file `<broker-instance>/etc/broker.xml` for editing.

Add an address configuration element with multicast routing type.

    <addresses>
       <address name="pubsub.foo">
          <multicast/>
       </address>
    </addresses>

When clients connect to an address with the multicast element, a subscription queue for the client will be automatically created for the client. It is also possible to pre-configure subscription queues and connect to them directly using the queue's Fully Qualified Queue names.

Optionally add one or more queue elements to the address and wrap the multicast element around them. This step is typically not needed since the broker will automatically create a queue for each subscription requested by a client.

    <addresses>
       <address name="pubsub.foo">
          <multicast>
             <queue name="client123.pubsub.foo"/>
             <queue name="client456.pubsub.foo"/>
          </multicast>
       </address>
    </addresses>

Figure 3. Point-to-Point with Two Queues

### Point-to-Point Address multiple Queues

It is actually possible to define more than one queue on an address with an anycast routing type. When messages are received on such an address, they are firstly distributed evenly across all the defined queues. Using Fully Qualified Queue names, clients are able to select the queue that they would like to subscribe to. Should more than one consumer connect directly to a single queue, Apache ActiveMQ Artemis will take care of distributing messages between them, as in the example above.

Figure 3. Point-to-Point with Two Queues

Note: This is how Apache ActiveMQ Artemis handles load balancing of queues across multiple nodes in a cluster. Configuring a Point-to-Point Address with two queues, open the file `<broker-instance>/etc/broker.xml` for editing.

Add an address configuration with Anycast routing type element and its associated queues.

    <addresses>
       <address name="address.foo">
          <anycast>
             <queue name="q1"/>
             <queue name="q2"/>
          </anycast>
       </address>
    </addresses>

### Point-to-Point and Publish-Subscribe Addresses

It is possible to define an address with both point-to-point and publish-subscribe semantics enabled. While not typically recommend, this can be useful when you want, for example, a JMS Queue say orders and a JMS Topic named orders. The different routing types make the addresses appear to be distinct.

Using an example of JMS Clients, the messages sent by a JMS message producer will be routed using the anycast routing type. Messages sent by a JMS topic producer will use the multicast routing type. In addition when a JMS topic consumer attaches, it will be attached to it’s own subscription queue. JMS queue consumer will be attached to the anycast queue.

Figure 4. Point-to-Point and Publish-Subscribe

Note: The behavior in this scenario is dependent on the protocol being used. For JMS there is a clear distinction between topic and queue producers and consumers, which make the logic straight forward. Other protocols like AMQP do not make this distinction. A message being sent via AMQP will be routed by both anycast and multicast and consumers will default to anycast. For more information, please check the behavior of each protocol in the sections on protocols.

The XML snippet below is an example of what the configuration for an address using both anycast and multicast would look like in `<broker-instance>/etc/broker.xml`. Note that subscription queues are typically created on demand, so there is no need to list specific queue elements inside the multicast routing type.

    <addresses>
       <address name="foo.orders">
          <anycast>
             <queue name="orders"/>
          </anycast>
          <multicast/>
       </address>
    </addresses>

## How to filter messages

Apache ActiveMQ Artemis supports the ability to filter messages using Apache Artemis Filter Expressions.

Filters can be applied in two places, on a queue and on a consumer.

### Queue Filter

When a filter is applied to a queue, messages are filtered before they are sent to the queue. To add a queue filter use the filter element when configuring a queue. Open up `<broker-instance>/etc/broker.xml` and add an address with a queue, using the filter element to configure a filter on this queue.

    <addresses>
       <address name="filter">
          <queue name="filter">
             <filter string="color='red'"/>
          </queue>
       </address>
    </addresses>

The filter defined above ensures that only messages with an attribute `"color='red'"` is sent to this queue.

### Consumer Filters

Consumer filters are applied after messages have reached a queue and are defined using the appropriate client APIs. The following JMS example shows how consumer filters work.

1. Define an address with a single queue, with no filter applied.

    <addresses>
       <address name="filter">
          <queue name="filter"/>
       </address>
    </addresses>

    ...
    // Send some messages
    for (int i = 0; i < 3; i ++) {
      TextMessage redMessage = senderSession.createTextMessage("Red");
      redMessage.setStringProperty("color", "red");
      producer.send(redMessage)

      TextMessage greenMessage = senderSession.createTextMessage("Green");
      greenMessage.setStringProperty("color", "green");
      producer.send(greenMessage)
    }

At this point the queue would have 6 messages: red,green,red,green,red,green

    MessageConsumer redConsumer = redSession.createConsumer(queue, "color='red'");

The redConsumer has a filter that only matches "red" messages. The redConsumer will receive 3 messages.

    red, red, red

The resulting queue would now be

    green, green, green

## Automatic Address/Queue Management

You can configure Apache ActiveMQ Artemis to automatically create addresses and queues, and then delete them when they are no longer in use. This saves you from having to preconfigure each address and queue before a client can connect to it. Automatic creation and deletion is configured on a per address basis and is controlled by following:

Parameter | Description
--- | ---
`auto-create-addresses` | When set to true, the broker will create the address requested by the client if it does not exist already. The default is `true`.
`auto-delete-addresses` | When set to true, the broker will be delete any auto-created address once all of it’s queues have been deleted. The default is `true`
`default-address-routing-type` | The routing type to use if the client does not specify one. Possible values are `MULTICAST` and `ANYCAST`. See earlier in this chapter for more information about routing types. The default value is `MULTICAST`.

### Auto Address Creation

- Edit the file `<broker-instance>/etc/broker.xml` and add the `auto-create-addresses` element to the `address-setting` you want the broker to automatically create.

- (Optional) Add the `address-setting` if it does not exist. Use the match parameter and the wildcard syntax to match more than one specific address.

- Set `auto-create-addresses` to `true`

- (Optional) Assign `MULTICAST` or `ANYCAST` as the default routing type for the address.

The example below configures an `address-setting` to be automatically created by the broker. The default routing type to be used if not specified by the client is MULTICAST. Note that wildcard syntax is used. Any address starting with `/news/politics/` will be automatically created by the broker.

    <address-setting match="/news/politics/#">
      <auto-create-addresses>true</auto-create-addresses>
      <default-address-routing-type>MULTICAST</default-address-routing-type>
    </address-setting>

### Auto Address Deletion

- Edit the file `<broker-instance>/etc/broker.xml` and add the `auto-delete-addresses` element to the `address-setting` you want the broker to automatically create.

- (Optional) Add the `address-setting` if it does not exist. Use the match parameter and the wildcard syntax to match more than one specific address.

- Set `auto-delete-addresses` to `true`

The example below configures an `address-setting` to be automatically deleted by the broker. Note that wildcard syntax is used. Any address request by the client that starts with `/news/politics/` is configured to be automatically deleted by the broker.

    <address-setting match="/news/politics/#">
      <auto-delete-addresses>true</auto-delete-addresses>
      <default-address-routing-type>MULTICAST</default-address-routing-type>
    </address-setting>

## "Fully Qualified" Queue Names

Internally the broker maps a client’s request for an address to specific queues. The broker decides on behalf of the client which queues to send messages to or from which queue to receive messages. However, more advanced use cases might require that the client specify a queue directly. In these situations the client uses a fully qualified queue name, by specifying both the address name and the queue name, separated by `::`.

> Note

> The string `::` should only be used for FQQN and not in any other context in address or queue names.

Currently Artemis supports fully qualified queue names on Core, AMQP, JMS, OpenWire, MQTT and STOMP protocols for both sending and receiving messages.

### Specifying a Fully Qualified Queue Name

In this example, the address foo is configured with two queues q1, q2 as shown in the configuration below.

    <addresses>
       <address name="foo">
          <anycast>
             <queue name="q1" />
             <queue name="q2" />
          </anycast>
       </address>
    </addresses>

In the client code, use both the address name and the queue name when requesting a connection from the broker. Remember to use two colons, `::`, to separate the names, as in the example Java code below.

    String FQQN = "foo::q1";
    Queue q1 session.createQueue(FQQN);
    MessageConsumer consumer = session.createConsumer(q1);

## Using Prefixes to Determine Routing Type

Normally, if the broker receives a message sent to a particular address, that has both `ANYCAST` and `MULTICAST` routing types enable, it will route a copy of the message to one of the `ANYCAST` queues and to all of the `MULTICAST` queues.

However, clients can specify a special prefix when connecting to an address to indicate which kind of routing type to use. The prefixes are custom values that are designated using the anycastPrefix and multicastPrefix parameters within the URL of an acceptor. When multiple values are needed, these can be separated by a comma.

### Configuring an Anycast Prefix

In `<broker-instance>/etc/broker.xml`, add the `anycastPrefix` to the URL of the desired acceptor. In the example below, the acceptor is configured to use `anycast://` for the `anycastPrefix`. Client code can specify `anycast://foo/` if the client needs to send a message to only one of the `ANYCAST` queues.

    <acceptor name="artemis">tcp://0.0.0.0:61616?protocols=AMQP;anycastPrefix=anycast://</acceptor>

### Configuring a Multicast Prefix

In `<broker-instance>/etc/broker.xml`, add the `multicastPrefix` to the URL of the desired acceptor. In the example below, the acceptor is configured to use `multicast://` for the `multicastPrefix`. Client code can specify `multicast://foo/` if the client needs to send a message to only one of the `MULTICAST` queues.

    <acceptor name="artemis">tcp://0.0.0.0:61616?protocols=AMQP;multicastPrefix=multicast://</acceptor>

## Advanced Address Configuration

### Static Subscription Queues

In most cases it’s not necessary to statically configure subscription queues. The relevant protocol managers take care of dynamically creating subscription queues when clients request to subscribe to an address. The type of subscription queue created depends on what properties the client request. For example, durable, non-shared, shared etc. Protocol managers use special queue naming conventions to identify which queues belong to which consumers and users need not worry about the details.

However, there are scenarios where a user may want to use broker side configuration to statically configure a subscription and later connect to that queue directly using a Fully Qualified Queue name. The examples below show how to use broker side configuration to statically configure a queue with publish subscribe behavior for shared, non-shared, durable and non-durable subscription behavior.

#### Shared, Durable Subscription Queue using max-consumers

The default behavior for queues is to not limit the number connected queue consumers. The max-consumers parameter of the queue element can be used to limit the number of connected consumers allowed at any one time.

Open the file `<broker-instance>/etc/broker.xml` for editing.

    <addresses>
       <address name="durable.foo">
          <multicast>
             <!-- pre-configured shared durable subscription queue -->
             <queue name="q1" max-consumers="10">
                <durable>true</durable>
             </queue>
          </multicast>
       </address>
    </addresses>

#### Non-shared, Durable Subscription Queue

The broker can be configured to prevent more than one consumer from connecting to a queue at any one time. The subscriptions to queues configured this way are therefore "non-shared". To do this simply set the max-consumers parameter to `1`:

    <addresses>
       <address name="durable.foo">
          <multicast>
             <!-- pre-configured non shared durable subscription queue -->
             <queue name="q1" max-consumers="1">
                <durable>true</durable>
             </queue>
          </multicast>
       </address>
    </addresses>

#### Non-durable Subscription Queue

Non-durable subscriptions are again usually managed by the relevant protocol manager, by creating and deleting temporary queues.

If a user requires to pre-create a queue that behaves like a non-durable subscription queue the purge-on-no-consumers flag can be enabled on the queue. When purge-on-no-consumers is set to true. The queue will not start receiving messages until a consumer is attached. When the last consumer is detached from the queue. The queue is purged (its messages are removed) and will not receive any more messages until a new consumer is attached.

Open the file `<broker-instance>/etc/broker.xml` for editing.

    <addresses>
       <address name="non.shared.durable.foo">
          <multicast>
             <queue name="orders1" purge-on-no-consumers="true"/>
          </multicast>
       </address>
    </addresses>

#### Exclusive Consumer Queue

If a user requires to statically configure a queue that routes exclusively to one active consumer the exclusive flag can be enabled on the queue.

When exclusive is set to true the queue will route messages to a single active consumer. When the active consumer that is being routed to is detached from the queue, if another active consumer exist, one will be chosen and routing will now be exclusive to it.

See Exclusive Queue for further information.

Open the file `<broker-instance>/etc/broker.xml` for editing.

    <addresses>
       <address name="foo.bar">
          <multicast>
             <queue name="orders1" exclusive="true"/>
          </multicast>
       </address>
    </addresses>

#### Disabled Queue

If a user requires to statically configure a queue and disable routing to it, for example where a queue needs to be defined so a consumer can bind, but you want to disable message routing to it for the time being.

Or you need to stop message flow to the queue to allow investigation keeping the consumer bound, but don't wish to have further messages routed to the queue to avoid message build up.

When enabled is set to true the queue will have messages routed to it. (default)

When enabled is set to false the queue will NOT have messages routed to it.

Open the file `<broker-instance>/etc/broker.xml` for editing.

    <addresses>
       <address name="foo.bar">
          <multicast>
             <queue name="orders1" enabled="false"/>
          </multicast>
       </address>
    </addresses>

Warning: Disabling all the queues on an address means that any message sent to that address will be silently dropped.

### Temporary Queues

For some protocols and APIs which only support monolithic "destinations" without the address/queue separation (e.g. AMQP, JMS, etc.) temporary queues are created by the broker using a UUID (i.e universally unique identifier) as the name for both the address and the queue. Because the name is a UUID it is impossible to create an `address-setting` for it whose `match` is anything but `#`.

To solve this problem one can specify the `temporary-queue-namespace` in `broker.xml` and then create an `address-setting` whose `match` value corresponds to the configured `temporary-queue-namespace`. When the `temporary-queue-namespace` is set and a temporary queue is created then the broker will prepend the `temporary-queue-namespace` value along with the `delimiter` value configured in `wildcard-addresses` (defaults to `.`) to the address name and use that to lookup the associated `address-setting` values.

Here's a simple example configuration:

    <temporary-queue-namespace>temp</temporary-queue-namespace>

    <address-settings>
       <address-setting match="temp.#">
          <enable-metrics>false</enable-metrics>
       </address-setting>
    </address-settings>

Using this configuration any temporary queue will have metrics disabled.

> Note:

> This setting does not change the actual name of the temporary queue. It only changes the name used to lookup the address-settings.

## Protocol Managers

A "protocol manager" maps protocol-specific concepts down to the core addressing model (using addresses, queues and routing types). For example, when a client sends a MQTT subscription packet with the addresses:

    /house/room1/lights
    /house/room2/lights

The MQTT protocol manager understands that the two addresses require `MULTICAST` semantics. The protocol manager will therefore first look to ensure that `MULTICAST` is enabled for both addresses. If not, it will attempt to dynamically create them. If successful, the protocol manager will then create special subscription queues with special names, for each subscription requested by the client.

The special name allows the protocol manager to quickly identify the required client subscription queues should the client disconnect and reconnect at a later date. If the subscription is temporary the protocol manager will delete the queue once the client disconnects.

When a client requests to subscribe to a point to point address. The protocol manager will look up the queue associated with the point to point address. This queue should have the same name as the address.

Note: If the queue is auto created, it will be auto deleted once there are no consumers and no messages in it. For more information on auto create see the next section Configuring Addresses and Queues via Address Settings

## Configuring Addresses and Queues via Address Settings

There are some attributes that are defined against an address wildcard rather than a specific address/queue. Here an example of an `address-setting` entry that would be found in the `broker.xml` file.

    <address-settings>
       <address-setting match="order.foo">
          <dead-letter-address>DLA</dead-letter-address>
          <auto-create-dead-letter-resources>false</auto-create-dead-letter-resources>
          <dead-letter-queue-prefix>DLQ.</dead-letter-queue-prefix>
          <dead-letter-queue-suffix></dead-letter-queue-suffix>
          <expiry-address>ExpiryQueue</expiry-address>
          <auto-create-expiry-resources>false</auto-create-expiry-resources>
          <expiry-queue-prefix>EXP.</expiry-queue-prefix>
          <expiry-queue-suffix></expiry-queue-suffix>
          <expiry-delay>123</expiry-delay>
          <redelivery-delay>5000</redelivery-delay>
          <redelivery-delay-multiplier>1.0</redelivery-delay-multiplier>
          <redelivery-collision-avoidance-factor>0.0</redelivery-collision-avoidance-factor>
          <max-redelivery-delay>10000</max-redelivery-delay>
          <max-delivery-attempts>3</max-delivery-attempts>
          <max-size-bytes>100000</max-size-bytes>
          <max-size-bytes-reject-threshold>-1</max-size-bytes-reject-threshold>
          <page-size-bytes>20000</page-size-bytes>
          <page-max-cache-size></page-max-cache-size>
          <address-full-policy>PAGE</address-full-policy>
          <message-counter-history-day-limit></message-counter-history-day-limit>
          <last-value-queue>true</last-value-queue> <!-- deprecated! see default-last-value-queue -->
          <default-last-value-queue>false</default-last-value-queue>
          <default-non-destructive>false</default-non-destructive>
          <default-exclusive-queue>false</default-exclusive-queue>
          <default-consumers-before-dispatch>0</default-consumers-before-dispatch>
          <default-delay-before-dispatch>-1</default-delay-before-dispatch>
          <redistribution-delay>0</redistribution-delay>
          <send-to-dla-on-no-route>true</send-to-dla-on-no-route>
          <slow-consumer-threshold>-1</slow-consumer-threshold>
          <slow-consumer-threshold-measurement-unit>MESSAGES_PER_SECOND</slow-consumer-threshold-measurement-unit>
          <slow-consumer-policy>NOTIFY</slow-consumer-policy>
          <slow-consumer-check-period>5</slow-consumer-check-period>
          <auto-create-jms-queues>true</auto-create-jms-queues> <!-- deprecated! see auto-create-queues -->
          <auto-delete-jms-queues>true</auto-delete-jms-queues> <!-- deprecated! see auto-delete-queues -->
          <auto-create-jms-topics>true</auto-create-jms-topics> <!-- deprecated! see auto-create-addresses -->
          <auto-delete-jms-topics>true</auto-delete-jms-topics> <!-- deprecated! see auto-delete-addresses -->
          <auto-create-queues>true</auto-create-queues>
          <auto-delete-queues>true</auto-delete-queues>
          <auto-delete-created-queues>false</auto-delete-created-queues>
          <auto-delete-queues-delay>0</auto-delete-queues-delay>
          <auto-delete-queues-message-count>0</auto-delete-queues-message-count>
          <config-delete-queues>OFF</config-delete-queues>
          <config-delete-diverts>OFF</config-delete-diverts>
          <auto-create-addresses>true</auto-create-addresses>
          <auto-delete-addresses>true</auto-delete-addresses>
          <auto-delete-addresses-delay>0</auto-delete-addresses-delay>
          <config-delete-addresses>OFF</config-delete-addresses>
          <management-browse-page-size>200</management-browse-page-size>
          <management-message-attribute-size-limit>256</management-message-attribute-size-limit>
          <default-purge-on-no-consumers>false</default-purge-on-no-consumers>
          <default-max-consumers>-1</default-max-consumers>
          <default-queue-routing-type></default-queue-routing-type>
          <default-address-routing-type></default-address-routing-type>
          <default-ring-size>-1</default-ring-size>
          <retroactive-message-count>0</retroactive-message-count>
          <enable-metrics>true</enable-metrics>
          <enable-ingress-timestamp>false</enable-ingress-timestamp>
       </address-setting>
    </address-settings>

The idea with address settings, is you can provide a block of settings which will be applied against any addresses that match the string in the `match` attribute. In the above example the settings would only be applied to the address "order.foo" address but you can also use wildcards to apply settings.

For example, if you used the `match` string `queue.#` the settings would be applied to all addresses which start with `queue.`

The meaning of the specific settings are explained fully throughout the user manual, however here is a brief description with a link to the appropriate chapter if available.

`dead-letter-address` is the address to which messages are sent when they exceed `max-delivery-attempts`. If no address is defined here then such messages will simply be discarded. Read more about undelivered messages.

`auto-create-dead-letter-resources` determines whether or not the broker will automatically create the defined `dead-letter-address` and a corresponding dead-letter queue when a message is undeliverable. Read more in the chapter about undelivered messages.

`dead-letter-queue-prefix` defines the prefix used for automatically created dead-letter queues. Read more in the chapter about undelivered messages.

`dead-letter-queue-suffix` defines the suffix used for automatically created dead-letter queues. Read more in the chapter about undelivered messages.

`expiry-address` defines where to send a message that has expired. If no address is defined here then such messages will simply be discarded. Read more about message expiry.

`auto-create-expiry-resources` determines whether or not the broker will automatically create the defined `expiry-address` and a corresponding expiry queue when a message expired. Read more in the chapter about undelivered messages.

`expiry-queue-prefix` defines the prefix used for automatically created expiry queues. Read more in the chapter about message expiry.

`expiry-queue-suffix` defines the suffix used for automatically created expiry queues. Read more in the chapter about message expiry.

`expiry-delay` defines the expiration time that will be used for messages which are using the default expiration time (i.e. 0). For example, if `expiry-delay` is set to "10" and a message which is using the default expiration time (i.e. 0) arrives then its expiration time of "0" will be changed to "10." However, if a message which is using an expiration time of "20" arrives then its expiration time will remain unchanged. Setting `expiry-delay` to "-1" will disable this feature. The default is "-1". Read more about message expiry.

`max-delivery-attempts` defines how many time a cancelled message can be redelivered before sending to the `dead-letter-address`. Read more about undelivered messages.

`redelivery-delay` defines how long to wait before attempting redelivery of a cancelled message. Default is `0`. Read more about undelivered messages.

`redelivery-delay-multiplier` defines the number by which the `redelivery-delay` will be multiplied on each subsequent redelivery attempt. Default is `1.0`. Read more about undelivered messages.

`redelivery-collision-avoidance-factor` defines an additional factor used to calculate an adjustment to the `redelivery-delay` (up or down). Default is `0.0`. Valid values are between 0.0 and 1.0. Read more about undelivered messages.

`max-size-bytes`, `page-size-bytes`, & `page-max-cache-size` are used to configure paging on an address. This is explained here.

`max-size-bytes-reject-threshold` is used with the address full `BLOCK` policy, the maximum size (in bytes) an address can reach before messages start getting rejected. Works in combination with `max-size-bytes` for AMQP clients only. Default is `-1` (i.e. no limit).

`address-full-policy`. This attribute can have one of the following values: `PAGE`, `DROP`, `FAIL` or `BLOCK` and determines what happens when an address where `max-size-bytes` is specified becomes full. The default value is `PAGE`. If the value is `PAGE` then further messages will be paged to disk. If the value is `DROP` then further messages will be silently dropped. If the value is `FAIL` then further messages will be dropped and an exception will be thrown on the client-side. If the value is `BLOCK` then client message producers will block when they try and send further messages. See the Flow Control and Paging chapters for more info.

`message-counter-history-day-limit` is the number of days to keep message counter history for this address assuming that `message-counter-enabled` is `true`. Default is `0`.

`last-value-queue` is deprecated. See `default-last-value-queue`. It defines whether a queue only uses last values or not. Default is `false`. Read more about last value queues.

`default-last-value-queue` defines whether a queue only uses last values or not. Default is `false`. This value can be overridden at the queue level using the `last-value` boolean. Read more about last value queues.

`default-exclusive-queue` defines whether a queue will serve only a single consumer. Default is `false`. This value can be overridden at the queue level using the `exclusive` boolean. Read more about exclusive queues.

`default-consumers-before-dispatch` defines the number of consumers needed on a queue bound to the matching address before messages will be dispatched to those consumers. Default is `0`. This value can be overridden at the queue level using the `consumers-before-dispatch` boolean. This behavior can be tuned using `delay-before-dispatch` on the queue itself or by using the `default-delay-before-dispatch` address-setting.

`default-delay-before-dispatch` defines the number of milliseconds the broker will wait for the configured number of consumers to connect to the matching queue before it will begin to dispatch messages. Default is `-1` (wait forever).

`redistribution-delay` defines how long to wait when the last consumer is closed on a queue before redistributing any messages. Read more about clusters.

`send-to-dla-on-no-route`. If a message is sent to an address, but the server does not route it to any queues (e.g. there might be no queues bound to that address, or none of the queues have filters that match) then normally that message would be discarded. However, if this parameter is `true` then such a message will instead be sent to the `dead-letter-address` (DLA) for that address, if it exists.

`slow-consumer-threshold`. The minimum rate of message consumption allowed before a consumer is considered "slow." Measured in units specified by the slow-consumer-threshold-measurement-unit configuration option. Default is `-1` (i.e. disabled); any other value must be greater than 0 to ensure a queue has messages, and it is the actual consumer that is slow. A value of 0 will allow a consumer with no messages pending to be considered slow. Read more about slow consumers.

`slow-consumer-threshold-measurement-unit`. The units used to measure the slow-consumer-threshold. Valid options are:

- MESSAGES_PER_SECOND
- MESSAGES_PER_MINUTE
- MESSAGES_PER_HOUR
- MESSAGES_PER_DAY

If no unit is specified the default MESSAGES_PER_SECOND will be used. Read more about slow consumers.

`slow-consumer-policy`. What should happen when a slow consumer is detected. `KILL` will kill the consumer's connection (which will obviously impact any other client threads using that same connection). `NOTIFY` will send a CONSUMER_SLOW management notification which an application could receive and take action with. Read more about slow consumers.

`slow-consumer-check-period`. How often to check for slow consumers on a particular queue. Measured in seconds. Default is `5`.

- Note: This should be at least 2x the maximum time it takes a consumer to process 1 message. For example, if the slow-consumer-threshold is set to 1 and the slow-consumer-threshold-measurement-unit is set to MESSAGES_PER_MINUTE then this should be set to at least 2 x 60s i.e. 120s. Read more about slow consumers.

`auto-create-jms-queues` is deprecated. See `auto-create-queues`. Whether or not the broker should automatically create a JMS queue when a JMS message is sent to a queue whose name fits the address `match` (remember, a JMS queue is just a core queue which has the same address and queue name) or a JMS consumer tries to connect to a queue whose name fits the address `match`. Queues which are auto-created are durable, non-temporary, and non-transient. Default is `true`.

`auto-delete-jms-queues` is deprecated. See `auto-delete-queues`. Whether or not the broker should automatically delete auto-created JMS queues when they have both 0 consumers and 0 messages. Default is `true`.

`auto-create-jms-topics` is deprecated. See `auto-create-addresses`. Whether or not the broker should automatically create a JMS topic when a JMS message is sent to a topic whose name fits the address `match` (remember, a JMS topic is just a core address which has one or more core queues mapped to it) or a JMS consumer tries to subscribe to a topic whose name fits the address `match`. Default is `true`.

`auto-delete-jms-topics` is deprecated. See `auto-delete-addresses`. Whether or not the broker should automatically delete auto-created JMS topics once the last subscription on the topic has been closed. Default is `true`.

`auto-create-queues`. Whether or not the broker should automatically create a queue when a message is sent or a consumer tries to connect to a queue whose name fits the address `match`. Queues which are auto-created are durable, non-temporary, and non-transient. Default is `true`. Note: automatic queue creation does not work for the core client. The core API is a low-level API and is not meant to have such automation.

`auto-delete-queues`. Whether or not the broker should automatically delete auto-created queues when they have both 0 consumers and the message count is less than or equal to `auto-delete-queues-message-count`. Default is `true`.

`auto-delete-created-queues`. Whether or not the broker should automatically delete created queues when they have both 0 consumers and the message count is less than or equal to `auto-delete-queues-message-count`. Default is `false`.

`auto-delete-queues-delay`. How long to wait (in milliseconds) before deleting auto-created queues after the queue has 0 consumers and the message count is less than or equal to `auto-delete-queues-message-count`. Default is `0` (delete immediately). The broker's `address-queue-scan-period` controls how often (in milliseconds) queues are scanned for potential deletion. Use `-1` to disable scanning. The default scan value is `30000`.

`auto-delete-queues-message-count`. The message count that the queue must be less than or equal to before deleting auto-created queues. To disable message count check `-1` can be set. Default is `0` (empty queue).

Note: the above auto-delete address settings can also be configured individually at the queue level when a client auto creates the queue.

For Core API it is exposed in createQueue methods.

For Core JMS you can set it using the destination queue attributes `my.destination?auto-delete=true&auto-delete-delay=120000&auto-delete-message-count=-1`

`config-delete-queues`. How the broker should handle queues deleted on config reload, by delete policy: `OFF` or `FORCE`. Default is `OFF`. Read more about configuration reload.

`config-delete-diverts`. How the broker should handle diverts deleted on config reload, by delete policy: `OFF` or `FORCE`. Default is `OFF`. Read more about configuration reload. `auto-create-addresses`. Whether or not the broker should automatically create an address when a message is sent to or a consumer tries to consume from a queue which is mapped to an address whose name fits the address `match`. Default is `true`. Note: automatic address creation does not work for the core client. The core API is a low-level API and is not meant to have such automation.

`auto-delete-addresses`. Whether or not the broker should automatically delete auto-created addresses once the address no longer has any queues. Default is `true`.

`auto-delete-addresses-delay`. How long to wait (in milliseconds) before deleting auto-created addresses after they no longer have any queues. Default is `0` (delete immediately). The broker's `address-queue-scan-period` controls how often (in milliseconds) addresses are scanned for potential deletion. Use `-1` to disable scanning. The default scan value is `30000`.

`config-delete-addresses`. How the broker should handle addresses deleted on config reload, by delete policy: `OFF` or `FORCE`. Default is `OFF`. Read more about configuration reload.

`management-browse-page-size` is the number of messages a management resource can browse. This is relevant for the `browse, list and count-with-filter` management methods exposed on the queue control. Default is `200`.

`management-message-attribute-size-limit` is the number of bytes collected from the message for browse. This is relevant for the `browse and list` management methods exposed on the queue control. Message attributes longer than this value appear truncated. Default is `256`. Use `-1` to switch this limit off. Note that memory needs to be allocated for all messages that are visible at a given moment. Setting this value too high may impact the browser stability due to the large amount of memory that may be required to browse through many messages.

`default-purge-on-no-consumers` defines a queue's default `purge-on-no-consumers` setting if none is provided on the queue itself. Default is `false`. This value can be overridden at the queue level using the `purge-on-no-consumers` boolean. Read more about this functionality.

`default-max-consumers` defines a queue's default `max-consumers` setting if none is provided on the queue itself. Default is `-1` (i.e. no limit). This value can be overridden at the queue level using the `max-consumers` boolean. Read more about this functionality.

`default-queue-routing-type` defines the routing-type for an auto-created queue if the broker is unable to determine the routing-type based on the client and/or protocol semantics. Default is `MULTICAST`. Read more about routing types.

`default-address-routing-type` defines the routing-type for an auto-created address if the broker is unable to determine the routing-type based on the client and/or protocol semantics. Default is `MULTICAST`. Read more about routing types.

`default-consumer-window-size` defines the default `consumerWindowSize` value for a `CORE` protocol consumer, if not defined the default will be set to 1 MiB (1024 * 1024 bytes). The consumer will use this value as the window size if the value is not set on the client. Read more about flow control.

`default-ring-size` defines the default `ring-size` value for any matching queue which doesn't have `ring-size` explicitly defined. If not defined the default will be set to -1. Read more about ring queues.

`retroactive-message-count` defines the number of messages to preserve for future queues created on the matching address. Defaults to 0. Read more about retroactive addresses.

`enable-metrics` determines whether or not metrics will be published to any configured metrics plugin for the matching address. Default is `true`. Read more about metrics.

`enable-ingress-timestamp` determines whether or not the broker will add its time to messages sent to the matching address. When `true` the exact behavior will depend on the specific protocol in use. For AMQP messages the broker will add a `long` message annotation named `x-opt-ingress-time`. For core messages (used by the core and OpenWire protocols) the broker will add a long property named `_AMQ_INGRESS_TIMESTAMP`. For STOMP messages the broker will add a frame header named `ingress-timestamp`. The value will be the number of milliseconds since the epoch. Default is `false`.

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