Subscription Description

 

The subscription description is an XML AtomPub document that defines the desired semantics for a subscription.

Subscription Description Properties

The subscription description contains the following properties. For more information, see the SubscriptionDescription Properties topic.

• LockDuration: XML datetime
  The default lock duration is applied to subscriptions that do not define a lock duration:

  • Range: 0 – 5 minutes. 0 means that the message is not locked.

  • Default: 30 seconds

• RequiresSession: True, False
  You can only set this property at subscription creation time. If set to true, the subscription will be session-aware and only SessionReceiver will be supported. Session-aware subscriptions are not supported through REST.

  • Default: false

• DefaultMessageTimeToLive: PTnHnMnS
  Determines how long a message lives in the subscription. Based on whether dead-lettering is enabled, a message whose Time To Live (TTL) has expired is either moved to the subscription’s associated DeadLetterQueue, or permanently deleted. If the topic specifies a smaller TTL than the subscription, the topic TTL is applied.

  • Range: 1 second – TimeSpan.MaxValue

  • Default: TimeSpan.MaxValue

• DeadLetteringOnMessageExpiration: True, False
  This field controls how Service Bus handles a message with an expired TTL. If it is enabled and a message expires, Service Bus moves the message from the queue into the subscription’s dead-letter sub-queue. If disabled, message is permanently deleted from the subscription’s main queue. Settable only at subscription creation time.

  • Default: false

• DeadLetteringOnFilterEvaluationExceptions: True, False
  Determines how Service Bus handles a message that causes an exception during a subscription’s filter evaluation. If the value is set to true, the message that caused the exception is moved to the subscription’s dead-letter queue. Otherwise, it is discarded. By default, this parameter is set to true, enabling you to investigate the cause of the exception. It can occur from a malformed message or some incorrect assumptions being made in the filter about the form of the message. Settable only at subscription creation time.

  • Default: true

• EnableBatchedOperations
  Enables or disables service-side batching behavior when performing operations for the specific queue. When enabled, Service Bus will collect/batch multiple operations to the backend to be more connection efficient. If you want lower operation latency, then you can disable this feature.

• ForwardTo
  The path to the recipient to which the message is forwarded.

• MaxDeliveryCount
  The maximum number of times Service Bus tries to deliver a message before that message is dead lettered or discarded.

• MessageCount
  Reports the number of messages in the queue as reported by the monitoring system.

• IsAnonymousAccessible
  Gets whether anonymous access is allowed.

• AuthorizationRules
  Gets the authorization rules for the description.

• Status
  Gets or sets the current status of the subscription (enabled or disabled). When a subscription is disabled, that subscription cannot send or receive messages.

• SupportOrdering
  Gets or sets whether the subscription supports ordering.

Important

The schema validation of the description during subscription creation is sensitive to the order of its child elements. For more information, see Queue Description.

Here are some things you can do with this API

• List all subscriptions under a given path:

  http://<serviceBusAddress>/$Resources/Subscriptions?$filter=startswith(path, ‘/my/test’)
  

• List all subscriptions updated in the last 5 minutes:

  http://<serviceBusAddress>/$Resources/Subscriptions?$filter=lastModifiedTime Gt  2011-08-09T21:44:36.2481552Z
  

• List all subscriptions having at least one message:

  http://<serviceBusAddress>/$Resources/Subscriptions?$filter=MessageCount Gt 0
  

See Also

Subscriptions
Create Subscription
Delete Subscription
Get Subscription
List Subscriptions
Example: Creating a Subscription