Re: [ws-rx] i119 - discussion of ballot

[Doug Bunting <Doug.Bunting@Sun.COM>]

Doug,

Some of this discussion certainly happened in the "chat room".  I 
(separately from the interop question) asked there why we were 
optimizing for the clustered corner case?  In the far more common case 
where one system is an RMS for multiple ongoing conversations, latency 
would be greatly reduced if /every/ message intended for that 
transfer-level destination were able to carry /every/ available 
acknowledgement.

As well, a correctness issue arises if and only if the clustered RMS is 
completely uncoordinated.  Seems as if we're optimizing for the poor 
implementation of a corner case.

thanx,
    doug

On 21/05/06 19:02, Doug Davis wrote:
>
> On last Thursday's call (or perhaps it was in the webconf) someone 
> asked why this issue wasn't seen during the interop - I wanted to 
> address this.  During the interop we only tested the most basic of 
> scenarios and in particular single endpoint to endpoint testing.  i119 
> will most likely show itself in cases where an RMS is running in a 
> clustered environment - clearly not something we would normally test 
> during an interop.  In such an environment the wsa:Address of the 
> acksTo might be common across all endpoints behind the gateway/cluster 
> and the routing may be based on reference parameters.  So, as a result 
> if the only thing an RMD examined when determining whether or not to 
> piggy-back Acks was just the wsa:Address then the Acks might flow to 
> the wrong back-end machine (if each one had its own RM state).  And of 
> course, the reverse can be true for SeqAck if the RMD was behind in a 
> clustered environment as well.  This is why its dangerous to not have 
> some form of EPR comparing (aside from just the wsa:Address) when 
> making these determinations.
> -Doug