ProxySQL at Nerdearla 2026: SQL Routing Meets a Wider Community

On September 25, I presented SQL Traffic Routing Without Breaking Consistency at Nerdearla in Buenos Aires. It was the first of two very different talks in two countries that week, before heading to Brazil for MySQL BR Conf.

Nerdearla, organized by Sysarmy, brings together people from across technology and open source. The 2026 edition ran from September 22 to 26, with the in-person program at Ciudad Cultural Konex from September 24. Attendance was free, with an online program as well.

That broad audience matters for a topic like SQL routing. The consequences of a routing decision reach well beyond the database team: they show up in application behavior, deployment choices, and what a user sees after clicking a button.

Starting with a booking, not a configuration file

I built the talk around a ticket-booking example. A customer books a ticket, the application commits the transaction, and the next page displays the confirmation. The database work appears straightforward. Add read replicas, however, and the confirmation query can reach a server that has not applied the booking yet.

The write succeeded. The user still sees the wrong result.

That example connects an infrastructure decision to something everyone building an application can recognize. It also gives us a useful way to discuss connection pooling, transactions, replication, and failover without treating each as an isolated feature.

The talk follows that thread from growing application connection pools to the conditions under which a read can safely move to a replica. ProxySQL provides mechanisms for managing traffic; the application’s expectations determine how those mechanisms should be used.

A database topic in a broader event

An event like Nerdearla creates room for this kind of discussion across specialties. You do not need to spend your days administering databases to care whether a booking confirmation is correct, or whether a service keeps working when a backend fails.

Thank you to the Nerdearla organizers, volunteers, and everyone who joined the session, in Buenos Aires or online. Making technical knowledge accessible to a broad community takes work, and it deserves recognition.

You can find SQL Traffic Routing Without Breaking Consistency in the Nerdearla program. I’ll return to the technical details in a follow-up, including the distinction between a healthy replica and one that is actually ready to serve a particular read.