[Freeipa-devel] [PATCH] #1794 - Speed up replica setup

[Simo Sorce]

On Mon, 2011-10-03 at 16:20 -0400, Simo Sorce wrote:
> Newer 389ds servers have a new option to have a different set of
> filtered attributes from normal replication.
> 
> This has been added in order to allow DS to replicate memberof
> attributes only during a total update so that we do not need to run a
> fixup memberof task on a replica at install time.
> This task is quite inefficient for big database and can take a long
> time. By replicating memberof while the DB is locked we are guaranteed
> the memberof list is consistent so we do not need a fixup.
> 
> This patch allows to enable this feature dynamically. If the server does
> not yet support the new option it falls back to the previous behavior.
> 
> Fixes: https://fedorahosted.org/freeipa/ticket/1794
> 
> I am sending the patch but it has been jointly developed at various
> stages by Nathan, JR, and me.
> 
> Simo.

After some thinking I found out that we cannot commit this patch until
the memberof plugin is converted to use the new transaction interfaces
for plugins, as otherwise it is possible to run into race conditions
where the member/memberof relations are not settled if a new replica is
installed while member attributes are being changed.

Granted the race is quite small and unlikely but real.
So please test and ack it, but we need to defer pushing to stable
branches until ds copes.
I think it is ok to push to master for testing, DS should have the
necessary support by the time we make another stable release from master
and in our test environments I am sure we will never hit the race.

Simo.

-- 
Simo Sorce * Red Hat, Inc * New York