When your Magento 2 store outgrows a single database server, the first wall you hit isn't CPU or memory — it's connection contention. MySQL can only handle so many concurrent connections before query latency spikes, transactions queue up, and your store grinds to a crawl.
The standard production fix is read/write replication splitting: offload SELECT queries to replica databases while writes go to the primary. Magento 2 has built-in support for this, but most developers don't configure it correctly — or at all.
In this guide, you'll learn exactly how to set up MySQL replication for Magento 2, configure the read/write connection split, handle replication lag, and monitor everything in production.
Why Replication Splitting Matters for Magento 2
Magento 2 is a database-heavy application. Every page load does dozens — sometimes hundreds — of SELECT queries:
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