RE: [wsn] Pull-type notification

["Rick Cobb" <rcobb@KnowNow.com>]

I mostly agree with Matt's suggestions, however...

> A second issue is whether GetMessages(40) should return the 40 oldest
> messages (traditional FIFO queue) or the 40 newest messages 
> (FILO, which is
> your proposal). I would prefer a traditional FIFO queue so 
> that we get the
> 40 oldest messages (with no clean afterwards) as this 
> provides the lossless
> durable delivery of existing messaging systems like JMS. If a 
> vendor wished
> to implement the get-with-clean or FILO behaviours you 
> suggest I think it
> should be on the basis of a policy statement. Note that 
> get-with-clean and
> FILO (get newest) should probably always be combined, since 
> not doing so
> results in shuffling the messages into a different order.

I don't necessarily agree with this advice; for example, KnowNow supports cursor-like access (with both back and next) into our similar functionality, so FILO does not necessarily imply get-with-clean.  This is particularly useful for consumers that are monitoring the actions of other consumers.

-- ReC