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.
- 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 theauto-create-addresses
element to theaddress-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
totrue
(Optional) Assign
MULTICAST
orANYCAST
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 theauto-delete-addresses
element to theaddress-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
totrue
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 a ::.
Currently Artemis supports fully qualified queue names on Core, AMQP, JMS, OpenWire, MQTT and STOMP protocols for receiving messages only.
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-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>
<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>
<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>
</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 messages-per-second.
Default is -1
(i.e. disabled); any other valid value must be greater than 0.
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
. 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.
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" management method exposed on the
queue control. Default is 200
.
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.