Last year, I made the first post in a small series, which aimed to highlight unique features of Percona Server for MySQL, by discussing binlog_space_limit option.

Today, I am going to discuss another important type of log available in MySQL that is enhanced in Percona Server for MySQL – the slow query log. The reason why I am doing this is that although this extension has existed since the very early times of versions 5.1 (over 10 years ago!), many people are still unaware of it, which I see from time to time when working with Support customers.

Default Slow Log Inadequacy

How many times have you been wondering why, whilst reviewing slow query logs, the very same query occasionally runs way slower than usual? There may be many reasons for that, but the standard slow …

A few days ago, a customer got in touch asking how they could use Percona Monitoring and Management (PMM) to monitor the roles played by each node in an InnoDB cluster. More specifically, they wanted to check when one of the nodes changed its role from Primary to Secondary, or vice-versa. PMM allows for a high level of flexibility and customization through its support for custom queries, and we just have to be creative on how we approach the problem. In this post, we present the steps we did to test our solution, including the deployment of a 3-node InnoDB Cluster hosted in the same server (for testing) and a PMM 2 server, and connecting them together. Even though this has already been covered in other blog …

The RED Method (Rate, Errors, Duration) is one of the more popular performance monitoring approaches.  It is often applied to Monitoring Microservices though there is nothing that prevents it from being applied to databases like MySQL.

In Percona Monitoring and Management (PMM) v2 we have all the required information stored in the ClickHouse database, and with the built-in ClickHouse datasource it is a matter of creating a dashboard to visualize the data.

While I was editing the dashboard, I added a few other panels, beyond what RED Method requires, in order to show some of the cool things you can do with Grafana + ClickHouse data source and …

In this webinar, Sveta Smirnova, MySQL Engineer at Percona, will uncover nuances of Percona XtraDB Cluster (PXC) schema upgrades and point out details you need to give extra attention to.

Percona XtraDB Cluster (PXC) is a 100% synchronized cluster in regards to DML operations. It is ensured by the optimistic locking model and ability to rollback transaction which cannot be applied on all nodes. However, DDL operations are not transactional in MySQL. This adds complexity when you need to change the schema of the database. Changes made by DDL may affect the results of the queries. Therefore all modifications must replicate on all nodes prior to next data access. For operations that run momentarily, it can be easily achieved, but schema changes may take hours to apply. Therefore in addition to the safest synchronous blocking schema upgrade method: TOI, – PXC supports more relaxed, though not safe, method RSU. RSU: Rolling Schema Upgrade is …

Even though Percona Monitoring and Management 2 (PMM) comes with a lot of dashboards and metrics out of the box, sometimes we need to extend the default metrics by running custom MySQL queries.

For example, suppose you want to have information about cached indexes from Innodb tables from innodb_cached_indexes table. That metric is not being captured by any default dashboard, but it is possible to extend PMM and make it capture the result of custom queries.

Getting Started With Custom Queries

Custom queries can be added to mysqld_exporter by adding them to the appropriate config file in /usr/local/percona/pmm2/collectors/custom-queries/mysql. There are three subdirectories inside it: high-resolution, low-resolution, and medium-resolution. PMM allows …

Our latest Solution Brief uses our relationship with Patreon to detail the ways that Percona services work together to provide customers with a complete database infrastructure solution.

Last year Patreon enlisted Percona’s help with their MySQL databases. Utilizing the full range of Percona Services (Managed Services, Support, Consulting, and Training) has allowed Patreon to make the most of their database infrastructure.

Percona worked with …

First I want to thank everyone who attended my May 21, 2020 webinar “How Safe is Asynchronous Master-Master Setup in MySQL?“. Recording and slides are available on the webinar page.

Here are answers to the questions from participants which I was not able to provide during the webinar.

Q: What do you generally think of hosting Relational Databases on VM’s as opposed to Bare metals?

A: With modern hardware and modern virtual machines this is absolutely possible. I know about many successful high loaded applications that run MySQL on VMs.

Just note that running a few VMs on a single physical machine may lead to resource loss rather than saving. For …

Percona engineers often need to analyze and review complex SQL database queries. Good formatting can make these SQL queries much easier to understand and work with. Without clear formatting, queries can become confusing and hard to debug.

Online query formatting services provide one set of solutions. Examples are Code Beautify, FreeFormatter, and sqlformat.org. However, many users are not comfortable sharing their queries with third-party services, especially if your SQL code contains confidential information.

This article examines alternatives to online tools for SQL query formatting tools that have been successfully used by Percona engineers. These solutions come in different types:

1. Plug-ins to your code editor or …

Here in Percona’s Training department, we like to think that we instruct our learners on the best practices for all things MySQL-related. In addition to performance tuning, query optimization, and replication configurations, another important topic is backups. Let’s dive in and discuss some of the basics and best practices around backups for MySQL.

Logical MySQL Backups

In MySQL, it is possible to take backups in two different forms. The first form, logical, is the most universal. Essentially, you create all of the necessary INSERT statements to repopulate your table data. The two most popular tools in the area are mysqldump and mydumper.

mysqldump

This tool has been around since the beginning and supports a slew of different options, too numerous to discuss in this post.

Here is a simple example for taking a logical backup of the …

Database backups are a fundamental requirement in almost every implementation, no matter the size of the company or the nature of the application. Taking a backup should be a simple task that can be automated to ensure it’s done consistently and on schedule. Percona has an enterprise-grade backup tool, Percona XtraBackup, that can be used to accomplish these tasks. Percona also has a Percona Kubernetes Operator for Percona XtraDB Cluster (PXC Operator), which has Percona XtraBackup built into it. Percona XtraBackup has the ability for both automated and on-demand backups. Today we will explore taking backups and restoring these backups using the PXC Operator deployed …