3.1.4.1.30 Event Subscription

Web Services Management Protocol Extensions for Windows Vista supports two event subscription types:

  • Collector-initiated event subscription

  • Publisher-initiated event subscription

Information about collector-initiated event subscriptions is specified in [DMTF-DSP0226] section 10.2.

Publisher-initiated subscription is an alternative approach to collector-initiated subscriptions. Publisher-initiated subscription is useful when security constrains do not allow open ports in firewalls and when the event publisher is not known, such as in a quarantine network.

Publisher-initiated subscriptions

Figure 6: Publisher-initiated subscriptions

ENUMERATE: In order to support publisher-initiated event subscriptions, the publisher of the event (Web Services Management Protocol Extensions for Windows Vista client) MUST send an Enumerate request to the collector as specified in section 3.1.4.8. The enumeration request MUST use the following resource URI:

http://schemas.microsoft.com/wbem/wsman/1/SubscriptionManager/Subscription

Subscriptions: The collector retrieves all active subscriptions and sends the list of Subscribe requests to the publisher in response to the Enumerate request. The client SHOULD initiate an optimized Enumeration so that the collector can send the results within the EnumerateResponse message, as specified in [DMTF-DSP0226] section 8.2.3. The enumeration results consist of a set of SubscriptionType elements as specified in section 2.2.4.41.

Upon receipt of the SubscriptionType elements, the publisher extracts the Envelope elements that contain SubscribeMsg messages. The publisher MUST process these Envelope elements as if they had been received as Subscribe requests over the wire, as specified in [DMTF-DSP0226] section 10.2. Any fault generated as a result of processing a SubscribeMsg message MUST use the MessageID of the corresponding SubscribeMsg message within the <s:Envelope/s:Header/wsman:RelatesTo> element of the fault.

Deliver: The publisher MUST deliver events as specified in [DMTF-DSP0226] section 10.2.

Ack: The collector SHOULD acknowledge the delivered events as specified in [DMTF-DSP0226] section 10.2.

Unsubscribe: The publisher MUST be able to cancel the subscription by sending a Unsubscribe request as specified in [DMTF-DSP0226] section 10.4.