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  1. Qpid
  2. QPID-3015

object creation and deletion via management


    • Type: New Feature
    • Status: Closed
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 0.8
    • Fix Version/s: 0.9
    • Component/s: C++ Broker
    • Labels:


        1. Problem

      At present queues and exchanges cannot be created via QMFv2. Having a
      means to do so would allow for more unified broker management. It
      would also allow applications that have a need to do this sort of
      broker manipulation to utilise a protocol independent, message-driven
      approach (as used in QMFv2 method invocation for example).

        1. Solution

      Define create() and delete() methods in the broker class in the management schema

      <method name="create" desc="Create an object of the specified type">
      <arg name="type" dir="I" type="sstr"
      desc="The type of object to create"/>
      <arg name="name" dir="I" type="sstr"
      desc="The name of the object to create"/>
      <arg name="properties" dir="I" type="map"
      desc="Type specific object properties"/>
      <arg name="lenient" dir="I" type="bool"
      desc="If specified, ignore unrecognised object properties as long as type is recognised"/>

      <method name="delete" desc="Delete an object of the specified type">
      <arg name="type" dir="I" type="sstr"
      desc="The type of object to delete"/>
      <arg name="name" dir="I" type="sstr"
      desc="The name of the object to delete"/>
      <arg name="options" dir="I" type="map"
      desc="Type specific object options for deletion"/>

      These would then be invoked like any other QMFv2 method. The types of
      object supported and the various properties these recognise will be

      I propose initially to support creation and deletion of three basic
      object types through this mechanism: queue, exchange and
      binding. Exchanges will have 'topic' as a type alias and will also
      recognise a sub-type property, corresponding to the AMQP 0-10 exchange
      type. The default will be topic exchanges. This matches the current
      usage in the addressing syntax for the messaging API.

        1. Rationale

      There are alternative approaches to message based creation and
      deletion that could be taken. For example:

      (1) Augment the QMFv2 protocol definition with opcodes for creation
      and deletion requests rather than using schema specific methods.

      (2) Define a mechanism for message based creation or deletion of
      objects that is entirely independent of QMFv2.

      The different approaches really only involve slightly different
      formats to the map messages sent and received, and perhaps the exact
      address to which they are sent. The basic mechanism would remain the

      However, I do not want to commit to altering the design of QMFv2 whose
      scope is broader than the basic broker management which qpidd
      requires. Neither do I want, at this stage at least, to replace QMFv2
      entirely. I chose the solution above as, for now, it seems like the
      most consistent option within the scope of Qpid 0.10.

      Likewise there are alternative ontologies for the objects thus created
      (or deleted). While 'queue' is probably obvious and uncontroversial,
      exposing exchanges and bindings are possibly less so. The rationale
      here is to find a simple solution that adequately (and intuitively)
      supports the AMQP 0-8 to 0-10 model for those familiar with it (which
      is after all the only model currently supported), while alluding to a
      transition to one where the pub-sub topic concept is more completely
      and explicitly supported.

      The set of types will be easily extensible (e.g. could even be extended to cover the links and bridges used in the current inter-broker routing

      Likewise in the future we can deprecate certain type- and/or property-

        1. Implementation Notes

      1. add above method definitions to management schema (add in some
      documentation on types and properties here and/or elsewhere)

      2. modify brokers to handle the new methods by creating the
      appropriate queues, exchanges or bindings

      3. create some tests and examples


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              • Assignee:
                gsim Gordon Sim
                gsim Gordon Sim
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                • Created: