Re: draft-ietf-ldapbis-protocol - controls

[Howard Chu <hyc@highlandsun.com>]

Jim Sermersheim wrote:
> I believe the broad interpretation of "appropriate" leads to far more 
> interoperability problems than the narrow view.
>  
> I'm glad to see that you don't believe a control can be partially applied.
>  
> The fact is, every implementation is going to behave quite differently 
> when it is allowed to either fail-over to ignoring a control or return 
> an error which was caused by the application of that control.
>  
> It will be extremely difficult to evaluate all error paths in code to 
> determine whether the error could be allieviated by ignoring any 
> non-critical controls that might be present. If one cooses not to do 
> that, one could instead, upon encountering any error condition, ignore 
> one non-critical control. If the operation still fails, one could ignore 
> another non-critical error (and probably should un-ignore that first 
> one). One could keep doing this until one has ignored enough 
> non-critical controls (rolling back the transaction each time), 
> until one determines that the operation is just going to fail no matter 
> what, or until the the operation succeeds (one hopes one hasn't 
> accidentally ignored a few non-critical controls that really wouldn't 
> have caused the error)

I am not suggesting that servers do any back-tracking to mitigate the 
failures encountered while processing a request accompanied by 
non-critical controls. Only stating that the presence of a non-critical 
control should not cause a server to choose not to *begin* executing the 
accompanying request. Once the server has decided to begin executing the 
request, any incidental errors should of course be reported back to the 
client as usual.

--
  -- Howard Chu
  Chief Architect, Symas Corp.       Director, Highland Sun
  http://www.symas.com               http://highlandsun.com/hyc
  Symas: Premier OpenSource Development and Support