Space Shuttle and ISS Sightings

Nothing to do with the original intent of this blog, but the NASA site has some great information about sightings of the Space station and shuttle. Shuttle docked last night and we watched them fly overhead at 22:53. Amazingly clear.

http://spaceflight.nasa.gov/realdata/sightings/cities/view.cgi?country=United_Kingdom®ion=England&city=Winchester

A quick guide to WS-BaseNotification

Base Notification...
A Web service, or other entity, disseminates information to a set of other Web services, without having to have prior knowledge of these other Web services.


Situation
Something that happens to produce a Notification

Notification
An XML element describing a Situation. Has a namespace qualified Qname and a schema

Subscription
A Web service requester creates a subscription by sending a Subscription request to a NotificationProducer. The requester does not have to be NotificationConsumer.


NotificationProducer:
produces Notification messages.

• Accepts incoming Subscribe requests
• containing a reference to a NotificationConsumer
• identifying Notifications the NotificationProducer should produce (can be described by boolean filters, including filtering by Topic - see [WS-Topics])
• The NotificationProducer agrees to produce Notification Messages or returns a fault
• NotificationProducer, can originate Notifications , or act as a Broker for some other entity (see WS-BrokeredNotification)

Implements the NotificationProducer interface which consists of the following message exchanges:

• Subscribe (ConsumerReference, Filter, InititalTerminationTime, SubscriptionPolicy) - Returns: SubcriptionEndpoint
• GetCurrentMessage (Topic) Returns: any
  

NotificationConsumer
An endpoint (represented by a WS-Addressing endpoint reference) which can receive Notifications.
May implement the generic Notify message exchange, or may implement its own catcher for notifications.

• Notify ( NotificationMessage) - No response
  

SubscriptionManager
An endpoint (represented by a WS-Addressing endpoint reference) that allows a service requester to manipulate Subscriptions. Typically implemented by NotificationProducer
Implements the SubscriptionManager interface which consists of the following message exchanges:

• Renew
• Unsubscribe
• PauseSubscription
• ResumeSubscription
  

PullPoints
It might not be possible for a NotificationProducer to call out to consumers, so BaseNotification defines a PullPoint interface to allow consumers to fetch messages. The Subscriber (or some other entity) can create a PullPoint and then use it as the ConsumerReference in Subscribe a request. The actual consumer then pulls Notifications from the PullPoint

PullPoint interface

• GetMessages
• DestroyPullPoint

Create PullPoint interface

• CreatePullPoint