Re: syncrepl and change in ordering

[Howard Chu <hyc@symas.com>]

Amol Kulkarni wrote:
> Hello,
>
> I've a openldap 2.4.30 syncrepl setup which is used by our applications.
> There are over 50 servers in the setup.
> I want to upgrade our application to the next version. In a single
> downtime, all servers cannot be upgraded. So the application will be
> upgraded in phase wise manner. Application upgrade requires some changes
> in ldap schemas. I want to update the schemas in same phases as the
> application so as to avoid separate downtime for schema update. I'm
> planning to update schema on the consumers first and provider last so
> that during the phases, some servers with old schemas and others with
> new schemas both replicate properly.

That's fine.

> schemachecking is set to off on all servers.

That's dangerous. You have no idea how long garbage data will persist in 
the system.

> I understand that new attributes added in schema will not be present on
> provider at the beginning, so there is no question of their replication.
> I've compared the schemas and found that none of the attributes is deleted.
> Only change is that for some attributes we have added 'ordering' and for
> some we have changed the 'equality'.

When you change matching rules, any existing index on those values will 
be invalid and will need to be regenerated using slapindex.

> I'm not using cn=config - if that is a consideration.

Makes no difference.

> So will it all work ?

Sounds fine overall.

> Is there a better way?
>
> Thanks in advance,
> Amol Kulkarni.


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