Nate:
I don't think MySQL replication has an issue with number of writes,
That has been our experience as well.
There are a couple of things to ensure: 1. The databases have to be sized such that they can handle all transactions occurring on the entire system, not just one side. 2. The network between them has to be high quality. We use premium bandwidth and keep our replicated servers in data centers. No back of the office connected via DSL/cable stuff.
As long as that is the case, replication has no problem keeping up and the transactions are sent across the network very quickly. It is not real time but close enough for our needs.
Neil
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