If you are going to flog ChronicDB, please at least disclose if you have some sort of relationship with said company. Most of your previous submissions pertain to ChronicDB.

Sorry for not disclosing I work on ChronicDB.

The author of the 6b article kindly provided more information about the time it took for the migration:

http://news.ycombinator.com/item?id=3621561

A couple of limitations of the Percona tool are related to changing data in tables with ON DELETE and ON UPDATE foreign key constraints and possible lock-ups of tables. It is a bi-directional replication tool, so it has to deal with the master-master replication case and as such does not guarantee data consistency.

Still the tool is helpful in many cases and congrats to Percona for developing it. Replication safety is a non-trivial problem in general.

They weren't doing a master-master sync.

ChronicDB is a hosted solution. That isn't even remotely what DeviantArt were looking for.

ChronicDB is not only a hosted solution. It also runs locally.

Not according to your own website.

ChronicDB is a combination of a software engineer and a hosted database: You run your database in our datacenters -- http://chronicdb.com/how_it_works

Your database will be hosted in our datacenters -- http://chronicdb.com/features