Recently, we performed a database engine major version upgrade in one of our customers’ environments from MySQL 5.7.26 to 8.0.27. After this version upgrade, we experienced issues with backups and replication for one of the nodes.

In this article, I will explain these issues in detail and recommend a way to take backups from a replication environment.

To begin with, we upgraded all the database nodes from 5.7.26 to 8.0.27 and as a recommended way we have a backup set-up from one of the replica nodes. Physical backups are being taken using Percona XtraBackup (PXB) so it does not lock the database during the backup.

With MySQL 5.7, a backup was taken using PXB 2.4. Due to the new data dictionaries, redo log and undo log in MySQL 8.0, we also upgraded PXB to 8.0.27 to avoid …

Operators hide the complexity of the application and Kubernetes. Instead of dealing with Pods, StatefulSets, tons of YAML manifests, and various configuration files, the user talks to Kubernetes API to provision a ready-to-use application. An Operator automatically provisions all the required resources and exposes the application. Though, there is always a risk that the user would want to do something manual that can negatively affect the application and the Operator logic.

In this blog post, we will explain how to limit access scope for the user to avoid manual changes for database clusters deployed with Percona Operators. To do so, we will rely on Kubernetes Role-based Access Control (RBAC).

The goal

We are going to have two roles: …

Table modifications are a common task for database administrators. In this blog, I’ll explain how to alter tables online in a controlled manner that does not disrupt application users or cause application downtime.

One of the tools in Percona Toolkit is pt-online-schema-change, a utility that alters the structure of a table without interfering with the reads or writes. The tool creates an empty copy of the table to alter and modify as desired before copying the rows from the original table into the new one.

When the copying is finished, it removes the original table and replaces it with the new one. Any changes made to data in the original tables during the copy process will be reflected in the new table as the tool creates triggers on …

Percona Server for MySQL 8.0.30-22 introduces a new authentication plugin, named authentication_fido. With this new plugin, it is possible to perform multi-factor authentication using hardware keys, or single-factor passwordless authentication with the same keys. This new plugin is in technical preview.

The plugin works exactly the same as the MySQL Enterprise FIDO authentication plugin, which is documented in detail in the official MySQL documentation and in the Percona Server for MySQL documentation

To try …

Percona Server for MySQL 8.0.30-22 introduces several improvements for the LDAP plugin: SASL support, support for fallback servers, and support for LDAP-based authorization. All improvements are in technical preview.

A description of the existing plugin features and usage instructions are available in the earlier blog post introducing the LDAP simple plugin, and in the Percona Server for MySQL documentation.

SASL connections

We introduced a new plugin similar to the MySQL …

What is a Delay Replica and how does it help?

MySQL Replication is useful, easy to set up, and used for very different purposes. For example:

• split reads and writes
• run data mining or reporting processes on them
• disaster recovery

To learn more, check out How Does MySQL Replication Work?

It’s important to mention that a replication server is not a backup by itself. A mistake on the source, for example, a DROP DATABASE or an UPDATE without a WHERE clause will be replicated nearly instantly to all replica servers. Simply having a replica is not going to be helpful here. How can we avoid that kind of mistake? By having a replica server that intentionally lags behind.

We can never avoid human error in database infrastructure operations. But …

The need to audit who is using a database and their activities is crucial in many environments. This functionality is available in the free, open source Audit Plugin that is included in Percona Server for MySQL.

The prerequisite for installing Percona’s Audit Log Plugin is to first install Percona Server for MySQL. Percona Server for MySQL is a drop-in replacement for MySQL.

The Audit Log Plugin itself is easy to install requiring only a shared object library to be loaded from a MySQL client program with INSTALL PLUGIN audit_log SONAME ‘audit_log.so’;.

stoker@testbox:~/Downloads$ mysql -u root -p mysql
Enter password:
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL …

We all know that data is important, and some businesses need historical data to be available all the time. The problem is that queries on large tables perform poorly if they are not properly optimized. We get many customer requests in Managed Services to purge/archive large tables, and to achieve it, we use pt-archiver.

Recently, we received a request to archive a large table, and the customer was worried about the downtime and performance issues during the archival.

We proposed a solution to the customer to archive the table using pt-archive. The idea is to archive old data to other tables and keep the latest data on the current table with minimal performance issues. All of the data will remain available and can be queried anytime.

In the blog, I will …

Earlier in the year, I was working on an issue where one of my clients had reported a massive influx in connection on their hosts after enabling Percona Monitoring and Management (PMM). This was something I had not seen before and after researching for a couple of days I discovered that if you monitor a MySQL instance with PMM configured to collect table statistics, and if the tables that it’s gathering statistics from are Federated, it will generate a connection on the remote host for the Federated tables, one for each Federated table in the instance. Let’s go over the details and provide some examples so we can understand this a bit better.

First, I’ll offer a reminder that a Federated table is simply a table that you can put in your MySQL instance that is empty locally and uses a network connection to get the data from …

One thing I commonly hear when working with my clients is “I want to change my DDL strategy in order to avoid locking in my database! The last time I used the same old method I ended up in a metadata lock situation!”

I agree that metadata locks can be painful, but unfortunately, it’s completely unavoidable, and changing from one tool to another won’t help with this. That said, it’s still worth it to examine how metadata locks work and what the impact is for each of the common tools and processes. In doing so we will see that all these tools will require metadata locks, but knowing more about how they work and how the use locking can help us determine the right tool for your specific use case.

Any time you make a change to a table a metadata lock is needed to ensure consistency between the table itself and MySQL’s data dictionary. In order for MySQL to establish this lock it has to wait for any query against the table in …