Re: search progress control

[Kurt Zeilenga <Kurt@OpenLDAP.org>]

A few comments...

Using only a response control is no good here as 99.99% of the work  
might go by without the server producing any response to the client.   
Allowing, in addition to a response control, an intermediate response  
message, would allow for progress updates when no responses are being  
produced.   Also, the control should be allowed with result, to  
indicate for instance how far the server got before it gave up.

Nothing here should be specific to search operation.  Progress is  
generally useful.

I think it would be good for the client, in requesting the  
information, give some indication of the frequency it wishes to be  
updated in (once per second?  once per minute?  once per hour).  This  
would only a suggestion.  The server must be allowed to return  
progress as convenient (and not overly burdensome) for it.

I'd recommend progress be measured using 0 to (2**31)-1 steps.  This  
allows the server to hide the number of candidates from the client,  
and provides sufficient precision for most any application.

Lastly, I think this discussion should be moved to the IETF LDAPext  
list for comment from the LDAP standardization community.

-- Kurt