'net replicate' issues - update

[tridge at samba.org]

Hi Kamen,

 > 'kccsrv' creates topology and related attributes correctly, but.... after
 > 'dreplsrv' refreshes partitions.
 > So we have something like this:
 > 1. DREPL: dreplsrv_refresh_partitions() - at this point repsFrom values are
 > empty
 > 2. KCC:     kccsrv_simple_update() - kcc set values for repsFrom
 > 3. DREPL: drepl_replica_sync() gets called - nothing happens dreplsrv
 >                  knows nothing about current topology

ahh, ok.

 > Simple workaround is to:
 > 1. move dreplsrv_refresh_partitions() call before scheduling partitions pull
 > in dreplsrv_periodic module
 > 2. call dreplsrv_refresh_partitions() while processing drepl_replica_sync()

I think we need a notification from the KCC to drepl telling it to
reload partitions when it has made any changes.

Just changing the order will help the startup problem, but it won't
fix things when the topology changes at runtime due to a new DC being
added.

So the simple solution is a new async message sent from the KCC to
drepl telling it to refresh. 

Cheers, Tridge