If you are bound in disk IO, adding master-master write nodes will not help you. The same number of bytes have to be written to the same volume whether they com

If you are bound in disk IO, adding master-master write nodes will not help you. The same number of bytes have to be written to the same volume whether they come from a replica or an application server. The only solution is partitioning/sharding, and there is no "easy button" to press and make that happen because it comes with its own limitations and trade-offs, and is something the application code will be intimately aware of.