Galera Cluster with 3 nodes: how I solved a MySQL availability problem

Tue, 17 Feb 2026 08:03:00 +0100

The ticket was laconic, as it often is when the problem is serious: “The database went down again. The application is stopped. Third time in two months.”

The client had a MariaDB on a single Linux server — a business management application used by about two hundred internal users, with load spikes during end-of-month accounting closures. Every time the server had a problem — a disk slowing down, a system update requiring a reboot, a process consuming all the RAM — the database crashed and with it the entire business operations.

From Single Instance to Data Guard: The Day the CEO Understood DR

Tue, 16 Dec 2025 08:03:00 +0100

The client was a mid-sized insurance company. Three hundred employees, an in-house management application running on Oracle 19c, a single physical server in the ground-floor server room. No replica. No standby. No disaster recovery plan.

For five years everything had worked. And when things work, nobody wants to spend money protecting against problems they’ve never seen.

The day everything stopped #

On a Wednesday morning in November, at 8:47 AM, the primary data group’s disk suffered a hardware failure. Not a logical error, not a recoverable corruption. A physical failure. The RAID controller lost two disks simultaneously — one had been degraded for weeks without anyone noticing, the other gave out suddenly.

High-Availability on Ivan Luminaria

Galera Cluster with 3 nodes: how I solved a MySQL availability problem

From Single Instance to Data Guard: The Day the CEO Understood DR

The day everything stopped #