The latest from the MySQL community

We’ve recently been dealing with an interesting customer case where a PXC version upgrade from 5.7 to 8.0 seemed to trigger a completely unexpected problem. Even though the workload and MySQL settings did not change, all PXC members began exhibiting sparse but regular bursts of massive disk writes. Yet the MySQL side workload statistics that we gathered during those bursts did not explain the volume of them at all!

Analyzing these bursts further with pidstat and iostat confirmed that the mysqld process was indeed the sole source of excessive disk writes, and digging further showed the responsible threads to be the Galera receiver thread responsible for subscribing to the replication stream, as well as the main connection threads on the writer node, or Galera applier …

At Percona Live Europe 2026, Dmitry Lenev and I presented JavaScript in My Database? Over My Dead Query, the story of component_js_lang, the V8-based JavaScript engine for Percona Server for MySQL 8.4. That experience told us few things:

• The presentation was seen as “for developers”
• What most DBA or DevOps heard was “JavaScript in the database” = “application logic in the database”

This let most of the people pictured developers shipping their business logic into stored procedures. Order workflows, pricing rules, REST calls, all running inside mysqld. 

That picture is wrong, and in this post I want to replace it with the right one, using the same four demos we showed on stage.

The fear is reasonable, the target is wrong

DBAs have earned their skepticism. Many of us have inherited a schema where thousands of lines of stored …

Over the period, we have witnessed how MySQL versioning evolved from 8.0 to 9.7 LTS, and now it has entered a new era: a calendar-based model.

Let’s first take a brief look at how MySQL versioning has evolved over time.

• Phase 1 – MySQL 8.0 (2018–2026) used a traditional single-track release model, with all new features and bug fixes rolled into the same 8.0 release line.
• Phase 2 – Oracle launches an Innovative/LTS dual-track model (Mid 2023). Innovation releases focus on new features and changes to short-lived performance on a quarterly basis. The LTS (Long Term Stable) release is steadier and has a long lifespan, with a cycle of 5 years of Premier Support + 3 years of Extended Support, and it typically launches every 2 years.
• Phase 3 – There are chains of Innovation releases following (8.1, …

A while ago, we discussed the cross-site replication feature of the Percona PXC operator. Recently, a similar cross-site replication feature was introduced in the Percona (PS MySQL) operator v1.2.0, a topology based on Group Replication/InnoDB Cluster.

In this blog post, we will explore how to add a DR Cluster to an existing DC Cluster to form a ClusterSet environment, which provides a seamless switchover between DC/DR members. The good part is that all the complexity and configuration will be managed by the Percona operator, with very few setup steps required.

Group Replication …

“Would making this capability available help a meaningful part of the MySQL community build better applications or run better systems?”

Q1. MySQL has recently made available several features from the enterprise tier to the MySQL Community Edition. What is driving this direction?

The simple answer is that Community Edition needs to stay strong for the people who build, run, and depend on MySQL every day. That includes developers, DBAs, startups, large enterprises, and software vendors.

When we bring broadly useful capabilities into Community Edition, particularly in areas like observability, high availability, performance, and developer experience, the whole MySQL ecosystem benefits. Users get a better platform, and we get better feedback from real workloads at scale.

Recent examples include replication observability and Group Replication capabilities, …

Starting with Percona XtraDB Cluster (PXC) 8.0, replication traffic encryption is enabled by default. That said, it’s common to find clusters running without TLS that suddenly need it: a new compliance requirement, an audit finding, a network segment that is no longer considered trusted.

PXC has a variable for exactly that case, pxc-encrypt-cluster-traffic, which handles SSL encryption for inter-node traffic, including State Snapshot Transfer (SST), Incremental State Transfer (IST), and the group communication the nodes use for replication.

The variable is not dynamic, and turning it on normally costs a full cluster restart since the node that encrypts traffic listens on ssl:// while its peers are still on tcp://. If a node joins the cluster with TLS enabled while remaining nodes don’t, the restarting node fails to reach out to the other peers with the following error:

2026-09-02T02:16:02.359992Z 0 [Note] [MY-000000] …

“Through transparent roadmaps, community-driven collaboration, contributor programs, and the MySQL Governance model, we aim to create an environment where innovation can accelerate while preserving the reliability, compatibility, security, and operational excellence that organizations around the world depend on.”

Q1. Oracle has announced a “new era” of MySQL community engagement at MySQL’s 30th anniversary. Can you walk us through what specifically prompted this strategic shift, and what concrete changes can the community expect to see in how Oracle approaches MySQL development and governance?

HVC: Throughout 2025 we celebrated 30 years of MySQL and reflected on the past and present, but more importantly, the future. The MySQL Community team sought feedback from around the globe on how to lead the next generation of MySQL innovation and open source collaboration. We came to Jason …

MySQL 9.7, a Long-Term Support (LTS) release, incorporates a variety of potential features spanning across multiple technical domains. This article covers some of the primary features introduced and evaluates their practical utility within the MySQL database environment.

Following the End-of-Life (EOL) status of MySQL 8.0, this subsequent LTS release is designed to provide enhanced stability alongside significant architectural innovations.

Let’s discuss each of these features below with some examples and usage.

Flow-control monitoring in Group Replication

Flow control monitoring has been improved and provides more granularity by introducing the additional status variables listed below.

• Gr_flow_control_throttle_count : It denotes the number of transactions that have been throttled.
• Gr_flow_control_throttle_time_sum :It denotes the time in microseconds that transactions have been …

It is time to talk again about Flow control and group replication. This time with a special eye on the use of Group Replication in the Kubernetes context. In this article we will dig a bit on how it works and what are the various side effects. 

The problem

Recently I was refining the calculation I use in the MySQL calculator for Operator given I was constantly encountering a very serious problem with the Percona Server Operator.

The problem is that when the deployment was/is serving a high level of traffic, it will, no matter what, end up in getting OMMKill by the K8 system. 

This because the pod was gradually consuming more and more memory, reaching the memory limit set in the CR specification. 

Now let me clarify a few things, to get straight to the facts.

…

Having a separate DR cluster for production databases is a modern day requirement or necessity for tech and other related businesses that rely heavily on their database systems. Setting up such a [DC -> DR] topology for Percona XtraDB Cluster (PXC), which is a virtually- synchronous cluster, can be a bit challenging in a complex Kubernetes environment.

Here, Percona Operator for MySQL comes in handy, with a minimal number of steps to configure such a topology, which ensures a remote side backup or a disaster recovery solution.

So without taking much time, let’s see how the overall setup and configurations look from a practical standpoint.

PXC Cross-Site/Disaster Recovery

DC Configuration

1) Here we have a three-node PXC cluster running on the DC side.

shell> kubectl get pods -n pxc
NAME                                               READY   STATUS …