[Date Prev][Date Next]
Re: overlay order important and not documented?
Francis Swasey wrote:
On 3/16/07 2:58 PM, Pierangelo Masarati wrote:
There are valid reasons to do it either way - for one thing,
instantiating the refint overlay on the replicas reduces network
traffic. Also if you have a hot standby setup you want the replicas to
be configured as nearly identically to the master as possible. (In
mirrormode the replica and the master should be identical, or mirror
Howard Chu wrote:
Yes, and that's probably the cleanest behavior. The overlay stack is
only supposed to be executed completely for operations that came from
the frontend. Any overlay on the stack should go through any other
overlays below it, but not through any that are above it.
However, the accesslog would be unusable for replication; I see the
point: refint should be present on the shadow as well, and do locally
refint modifications, right?
I disagree! Since the only modifications that arrive at the replicas
(or shadows) came from the master. I should be able to set up the
overlays for unique and refint on the master and be done with it. I
should not have to waste the cpu cycles on each of the replicas to
perform the same operations that were already figured out and done on
the master ldap server.
-- Howard Chu
Chief Architect, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc
Chief Architect, OpenLDAP http://www.openldap.org/project/