More policy use cases

[peter_niblett@uk.ibm.com]

I'm posting two more elaborations suggested by Matthew Roberts..

The BaseNotification doc suggests 'Message rate' - ie at most 3 per second as one example. A variation on this is the standard batch size / timeout that could be used to indicate the preferred number of NotificationMessages to be delivered in a single Notify call. This would reduce the number of service invocations, which could be useful for high throughput systems. As usual the timeout provides a maximum length of time to wait to complete the batch before delivering whatever has been received. (timeout is not applicable if batchSize is 1, with suggested defaults of batchSize=1, timeout=1000 milliseconds).


Notification format  - similar to Dialect only for body content. The subscriber could request that the message sent be in a particular format (eg XML, CSV, application specific, Text, Bytes - including encoding/ccsid values). This requires the NotificationProducer to understand and be able to translate between the various possibilities - an extension of the capabilities of the bus as a whole. A combination of useNotify=false and this idea would allow the NotificationProducer to drive the data bytes directly at the client in native format.