I was planning to use the load balancer in the 2nd configuration as well. In both cases only a single master will receive the write requests. The 2nd configuration would still work in the event of a failure of the load balancer.
I don't know if delta-syncrepl can handle two syncrepl statements getting the same data. I would think that would cause a lot of problems. Although I guess it would know it already got that change? I'm curious to know the results of your experiments. ;)
--Quanah -- Quanah Gibson-Mount Principal Software Engineer Zimbra, Inc -------------------- Zimbra :: the leader in open source messaging and collaboration