The latest from the MySQL community

Alkin Tezuysal Director of Services at Altinity Inc. MySQL 9.7 came out on April 21 and I’ve been going through the release notes so you don’t have to. The short version: Oracle has made several previously Enterprise-only features available in the Community Edition, the Hypergraph Optimizer is now free for everyone, and if you’re still on MySQL 8.0, it […]

Many applications start with a simple database setup: create one MySQL user, give it access to the application schema, put the credentials in the app config, and move on. That may work at first, but it is not a good long-term security model. A better approach is to use separate MySQL users for separate application […]

In this blog, I am going to share a real-world debugging case study where a routine Percona XtraDB Cluster node restart led to an unexpected failure. I will walk through what we observed, what we checked, and how we ultimately identified the root cause.

Let’s see how the maintenance goes. It was supposed to be a simple restart. The kind you’ve done a hundred times. You SSH in, run the maintenance, bring the node back up, and go grab a coffee. Except this time, the coffee went cold on the desk… because MySQL refused to start.

The Problem

The error log of Percona XtraDB Cluster (8.0) had the following information:

2025-11-05T05:26:10.982984Z 0 [ERROR] [MY-000059]   [Server] SSL error: Unable to get certificate from '/var/lib/mysql/server-cert.pem'.
2025-11-05T05:26:10.983030Z 0 [Warning] [MY-013595] [Server] Failed to initialize TLS for channel: mysql_main. See below for the description of exact issue. …

Percona Monitoring and Management is a great open source database monitoring, observability, and management tool. Query analytics is one of the prominent features DBA uses actively to trace the incidents and query performance identification.

We all know and love the Query Analytics (QAN) dashboard… It’s the first place we look when an incident alert fires or when a developer asks, “Why is the app slow?” or “What was going on during the midnight production outage?”

But sometimes, the standard dashboards just don’t tell the whole story or maybe are not clear enough. QAN is great, but shouldn’t we have more? If you have PMM running, you already have a Ferrari engine under the hood: ClickHouse. Most of us just drive it in first gear using the default UI.

In this post, we are going to take the training wheels off. We will bypass the standard QAN interface and talk directly to the ClickHouse backend to …

Introduction

Many MySQL configurations inherit redo log sizing from defaults, aging blog posts, or configuration folklore.

innodb_redo_log_capacity gets set once… and then quietly fades into the background.

But redo log capacity directly shapes how efficiently MySQL absorbs writes, manages checkpoint pressure, and handles burst-heavy workloads.

Set it too low, and aggressive flushing can throttle throughput.
Set it too high, and crash recovery can become painfully long.

Redo logs are more than crash insurance.

They are part of your write-performance architecture.

Redo logs are the shock absorbers of write-heavy MySQL. Too small, and performance jolts. Too large, and recovery drags.

Why Redo Logs Matter

InnoDB redo logs are often described as crash recovery journals, but that description undersells their real operational value.

Redo …

Recently, we received an alert for one of our Managed Services customers indicating that the auto_increment value for the table was 80% of its maximum capacity. The column was INT UNSIGNED, which has a limit of 4,294,967,295.

At 80%, we have enough time to change it to BIGINT.…. Right? Let’s see.

So we used pt-online-schema-change to perform the alter.

It started running at a good pace but slowed over time.

Why?

Well, let’s look at the definition of the table:

mysql> show create table myschema.mytableG
*************************** 1. row ***************************
       Table: mytable
Create Table: CREATE TABLE `mytable` (
  `id` int unsigned NOT NULL AUTO_INCREMENT,
  `long_column` …

Once you move from self-managed MySQL to a MySQL DB System with HeatWave on OCI, the tuning story changes in an important way. On a self-managed server, you worry about two layers: MySQL and the operating system. On OCI MySQL DB Systems with HeatWave, Oracle runs your MySQL instance as a fully-managed service and explicitly […]

MySQL 9.7 introduces a long-requested improvement: Child table triggers are executed during SQL-layer foreign key cascades. Historically, cascades executed inside InnoDB did not invoke child table triggers, which created gaps in auditing, derived data maintenance, and observability. When a parent row change triggered cascading changes in child tables, those child table triggers were not executed. This […]

Announcing Vitess 24 # The Vitess maintainers are happy to announce the release of version 24.0.0, along with version 2.17.0 of the Vitess Kubernetes Operator. Version 24.0.0 expands query serving capabilities for sharded keyspaces, modernizes Vitess's observability stack, and introduces faster replica provisioning through native MySQL CLONE support. The companion v2.17.0 operator release brings significant improvements to scheduled backups, with new cluster- and keyspace-level schedules that make production backup management much easier to configure at scale.

Best practices for MySQL customers and users in an AI-accelerated security landscape: A practical guide to hardening MySQL and the environment around it Oracle recently described how AI is transforming vulnerability detection and response. The latest generation of AI is increasing the speed and scale at which vulnerabilities can be identified and remediated. Oracle is […]