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 …

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 […]

TL;DR

Percona XtraBackup is a 100% open-source backup solution for Percona Server for MySQL and MySQL®. It is designed for high-availability environments, performing online, non-blocking, and highly secure backups of transactional systems without interrupting your production traffic.

While full backups work for small databases, large-scale systems rely on incremental backups to save space and time. However, the “prepare” stage, required to make the incremental backups consistent, was slow because XtraBackup processed the .delta files serially. The .delta files are generated per table and store only the modifications since the last backup.

Great news! In XtraBackup versions …

Last week, ProxySQL announced that they are taking over the maintenance and development of Orchestrator, the MySQL high-availability and topology management tool originally authored by Shlomi Noach. You can read their announcement here: Announcing the future of Orchestrator.

We want to briefly share Percona’s position on the news.

We welcome this

Orchestrator became the de facto standard for MySQL topology management and automated failover, and it has been a foundational tool in the ecosystem for over a decade. When the upstream project was archived, many operators were left running internal forks. A revived project under active development, with a stated roadmap and continued Apache 2.0 licensing, is good news for the MySQL community, and we’re glad to see ProxySQL step up to take it on. Thanks are due to Shlomi Noach …

Introduction Replication performance depends on every stage in the pipeline, from the source database to transport and ultimately to commit on the replica. On the replica side, much of that performance comes down to how efficiently changes are read, scheduled, and applied under real operational pressure. In practice, that directly affects steady-state lag, backlog recovery […]