Solace Operation Binding v0.4.0

The Solace operation binding is the most detailed and important binding for defining behavior in a Solace-based API. It specifies the array of destinations that a message will be sent to or received from.

Overview

This binding allows you to define a list of destinations for a single operation. Each destination can be a queue or a direct topic subscription. This is critical for describing common Solace patterns, such as publishing a message that is consumed by multiple durable queues and also by direct, real-time subscribers.

Operation Properties

Property	Type	Required	Description
bindingVersion	string	No	Binding version (defaults to 0.4.0).
destinations	array	No	An array of destination objects.
timeToLive	integer	No	Lifetime of the message in milliseconds.
priority	integer	No	Message priority from 0 to 255.
dmqEligible	boolean	No	If true, the message can be moved to a Dead Message Queue. Defaults to false.

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Destination Object

Each object in the destinations array defines a single destination.

Property	Type	Required	Description
destinationType	string	Yes	queue or topic.
deliveryMode	string	No	direct or persistent. Defaults to direct.
queue	object	No	A queue object, required if destinationType is queue.
topicSubscriptions	array	No	A list of topic subscriptions for a topic destination.

Destination Property Details

• destinationType:
  • queue: The destination is a durable queue that spools messages.
  • topic: The destination is a direct topic subscription for non-durable, real-time delivery.
• deliveryMode:
  • direct: At-most-once delivery. Low latency, high throughput.
  • persistent: At-least-once delivery (guaranteed). Messages are spooled to the destination.

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Queue Object

The queue object is used when destinationType is queue.

Property	Type	Required	Description
name	string	No	The name of the queue.
topicSubscriptions	array	No	A list of topic subscriptions that the queue listens to.
accessType	string	No	exclusive or nonexclusive. Defines how consumers access the queue.
maxMsgSpoolUsage	string	No	Maximum spool usage for the queue (e.g., "100MB").
maxTtl	string	No	Maximum time-to-live for messages spooled to the queue (e.g., "3600s").

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Examples

Guaranteed Publishing to a Queue

This operation sends a persistent message to a queue named q_user_updates, which subscribes to a specific topic.

operations:
  sendUserUpdate:
    action: send
    bindings:
      solace:
        bindingVersion: '0.4.0'
        destinations:
          - destinationType: 'queue'
            deliveryMode: 'persistent'
            queue:
              name: 'q_user_updates'
              topicSubscriptions:
                - 'user/signedup'

Consuming from Multiple Destinations

This operation describes a consumer that binds to a durable queue for guaranteed delivery but also subscribes directly to a topic for real-time, non-persistent alerts.

operations:
  receiveCriticalEvents:
    action: receive
    bindings:
      solace:
        bindingVersion: '0.4.0'
        destinations:
          - destinationType: 'queue'
            deliveryMode: 'persistent'
            queue:
              name: 'q_critical_events'
              topicSubscriptions:
                - 'events/critical/>'
          - destinationType: 'topic'
            deliveryMode: 'direct'
            topicSubscriptions:
                - 'events/alerts/realtime'

Changelog

Version 0.4.0

• Refined the structure for destinations array.
• Clarified the relationship between destinationType, deliveryMode, queue, and topicSubscriptions.