Re: (ITS#3939) min/max function extension to LDAP protocol

[quanah@stanford.edu]

--On Saturday, August 20, 2005 8:33 AM -0700 "Kurt D. Zeilenga" 
<Kurt@OpenLDAP.org> wrote:

I realized much of what I wrote last night was muddled by tiredness. 
Hopefully this is clearer. :)

OpenLDAP 2.3.5 Scenario:

Consumer connects to Provider, sends its cookie.

Provider checks to see if the consumer cookie is current.

  a) If yes, no updates needed.
  b) If no, determine if the cookie is still valid by seeing if there are 
any entries with an entryCSN <= consumer cookie.  Then determine what type 
of updates to do.


OpenLDAP 2.3.6 Scenario:

Consumer connects to Provider, sends its cookie.

Provider checks to see if the consumer cookie is current.

   a) If yes, no updates needed.
   b) If no, see if there is an entry where its entryCSN is equal to the 
provided consumer cookie.
        i) If yes, determine what updates are needed.
       ii) If no, determine if the cookie is still valid by seeing if there 
are any entries with an entryCSN <= consumer cookie.  Then determine what 
type of updates to do.


The whole issue here is around (b).  If the provider has received a delete 
of the entry that has the entryCSN value stored in the consumer's cookie, 
the provider is going to move to option (ii).  If the provider has received 
a modification of the entry that had the entryCSN value stored in the 
consumer's cookie, it is going to move to option (ii).

A better check for (ii) to validate the consumer's cookie is simply is the 
minimum value of entryCSN in the provider's database less than or equal to 
the consumer's cookie.  This skips trolling through the providers database 
looking at every entryCSN.

--Quanah

--
Quanah Gibson-Mount
Principal Software Developer
ITSS/Shared Services
Stanford University
GnuPG Public Key: http://www.stanford.edu/~quanah/pgp.html

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