DataDistributionInaDiverseCommunity

From SPA Wiki

Data Distribution in a Diverse Community

(that’s the travel information community)

Slides on conference CD - about 5 MB.

Groups designed models to satisfy the use case shown in the slides…a travel information receiver gets the initial state of an aspect of the travel network and keeps it up to date.

Both groups proposed event channel models with filters. Initial state would be achieved either by a parallel interface or by layering a request protocol on the event channel.

Other features / factors were considered important:

• Choice of push/pull
• QoS
• User defined events
• Strong/weak typing
• Built-in support for session management
• Built-in support for deletion / termination
• Complexity / Simplicity - the most important single factor in this domain.
• Federation - but conflict with ownership, so not in this domain.

We didn’t get time to draw a consensus on the preferred blend - see the slides for interfaces used in real systems.

The move (for largely non-technical reasons) from standardisation of remote interfaces to standardisation of local APIs in a bridge was less surprising to some than others.

Instead of the local API group exercise, the session chose to hear about some metadata applications in this domain.

UK attendees were just as interested in the travel information content as the software stuff …so for more info check out some of the following:

• Highways Agency 1 and choose “Real-time traffic information”
• Trial metadata registry for our domain 2
• Travel Information Highway 3 - the main community site, although you have to join to get any really interesting stuff.

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