Re: understanding replication

Aaron Richton wrote:
> On Mon, 1 Mar 2010, Alan Batie wrote:
>
>> I'm a little puzzled by the openldap replication docs; in particular
>> rid, entryuuid, entrycsn, contextcsn fields that I see referenced a lot.
> [...]
>> Basically, I'd like to understand the replication process at a slightly
>> higher level than http://www.openldap.org/doc/admin24/syncrepl.html
>> describes not quite completely enough...
>
> In addition to the Admin Guide, I suggest reading RFC4533 and the other
> material in the doc/ directory of the distribution. Also, even if you're
> not particularly adept at C, you may wish to read the comments in
> syncprov.c source file. The terms you're asking about are the names that
> OpenLDAP uses in its implementation; hopefully with the RFC in hand it
> will become clear how the concepts map to the names, and you can always
> ask if anything is still unclear.
>
>> I'm guessing the rid is a random chosen id number for the secondary
>> server (consumer?) that is used to compare the master db (entryuuid?)
>> for context? information that indicates sync state?
>
> rid is chosen by administrator (i.e. manually configured). I honestly
> forget what it's used for nowadays...I vaguely remember "nothing" and/or
> "it's only important for multimaster." I'm certain this is in the archives
> of openldap-software and/or openldap-devel, but I'll leave the search to
> you.

Like the manpage says:

 >>>
rid identifies the current syncrepl directive within the replication consumer 
site.
<<<

It's only use is to give the slapd -c option something to reference. Nothing else.

-- 
   -- Howard Chu
   CTO, Symas Corp.           http://www.symas.com
   Director, Highland Sun     http://highlandsun.com/hyc/
   Chief Architect, OpenLDAP  http://www.openldap.org/project/