Historically MySQL is great in horizontal READ scale. The scaling, in that case, is offered by the different number of Replica nodes, no matter if using standard asynchronous replication or synchronous replication.

However, those solutions do not offer the same level of scaling for writes operation.

Why? Because the solutions still rely on writing in one single node that works as Primary. Also, in the case of multi-Primary, the writes will be distributed by transaction. In both cases, when using virtually-synchronous replication, the process will require certification from each node and local (by node) write; as such, the number of writes is NOT distributed across multiple nodes but duplicated.

The main reason behind this is that MySQL is a relational database system (RDBMS), and any data that is going to be written in it must respect the RDBMS …

Sometimes crucial data sharing is avoided because of compliance rules, organizational policies, or numerous security concerns. The common use cases involve sharing pt-mysql-summary, pt-stalk, and other OS-related details to assist Support Engineers or any other third-party team troubleshoot database-related issues.

In this context, pt-secure-collect is a very important utility from Percona, which helps capture the required information securely and also provides aid in masking the existing information.

Pt-secure-collect helps in collecting, sanitizing, and encrypting data from various sources. By default, this utility collects the output with the help of pt-stalk, pt-summary, and pt-mysql-summary.

Let’s see how this tool …

As we approach end of life for MySQL 5.7 later this year, many businesses are currently working towards upgrading to MySQL 8. Such major version upgrades are rarely simple, but thankfully there are tools that can help smooth the process and ensure a successful upgrade.

It should be noted that while the technical aspects of the upgrade process are beyond the scope of this blog post, it is crucial to create a testing environment to verify the upgrade before proceeding to upgrade your production servers, particularly with MySQL 8. 

As there is no procedure for downgrading from MySQL 8 other than restoring a backup, testing and validation are more critical than previous major version …

During the early stages of my career, I was captivated by the theories and concepts surrounding foreign keys and how they empowered us to maintain data integrity. However, in practical application, I have found them to be quite challenging to manage. I am sure you’re a champion DBA, but I keep my distance from foreign keys.

With that short story as a background, this post aims to address the dilemma that arises when utilizing the pt-online-schema-change tool on tables that contain foreign keys.

We already know what one of the most used Percona tools pt-online-schema-change is and how pt-online-schema-change handles foreign keys.

When utilizing the pt-online-schema-change tool to alter a table, such as …

Indexes are crucial for optimizing query execution times in databases, but having an excessive number of indexes, or redundant ones, can negatively impact performance. While pt-duplicate-key-checker is the go-to tool for identifying duplicate or redundant indexes in MySQL, it may not catch all duplicates.

In this blog post, we’ll put ourselves to the test and see if we can identify duplicate and redundant indexes in MySQL. Toward the end, we will identify what the pt-duplicate-key-checker doesn’t.

The unique quiz

Consider the following MySQL table definition. Let’s put our brains to work and note any of the duplicate or redundant indexes (play fair, don’t cheat):

CREATE TABLE `table_with_lot_of_trouble` (
`id` int NOT NULL,
`col1` varchar(1) DEFAULT NULL,
`col2` varchar(2) DEFAULT NULL,
`col3` varchar(3) …

On MySQL and Percona Server for MySQL, there is a schema called information_schema (I_S) which provides information about database tables, views, indexes, and more.

A lot of useful information can be retrieved from this schema, for example, table metadata and foreign key relations, but trying to query I_S can induce performance degradation if your server is under heavy load, as shown in the following example test.

Disclaimer: This blog post is meant to show a less-known problem but is not meant to be a serious benchmark. The percentage in degradation will vary depending on many factors {hardware, workload, number of tables, configuration, etc.}.

Test

The test compares a baseline of how the server behaves while “under heavy load but no queries against I_S” vs. ” under heavy load + I_S queries” to …

2022 was an exciting year for Percona Monitoring and Management (PMM). We’ve added and improved many features, including Alerting and Backup Management. These updates are designed to keep databases running at peak performance and simplify database operations. But as companies grow and see more demand for their databases, we need to ensure that PMM also remains scalable so you don’t need to worry about its performance while tending to the rest of your environment.

PMM2 uses VictoriaMetrics (VM) as its metrics storage engine. Percona’s co-Founder Peter Zaitsev wrote a detailed post about migration from Prometheus to VictoriaMetrics, One of the most significant differences in …

Let’s look at how you can run Percona databases on Kubernetes, the easy way.

Chances are that if you are using the latest Percona Monitoring and Management (PMM) version, you have seen the availability of the new Percona Database as a Service (DBaaS). If not, go and get a glimpse of the fantastic feature with our docs on DBaaS – Percona Monitoring and Management.

Now, if you like it and wanna give it a try! (Yay!), but you don’t wanna deal with Kubernetes, (nay)o worries; we have a tool for you. Introducing the Percona DBaaS Infrastructure Creator, or Percona My Database as a Service (MyDBaaS).

My Database as a Service

…

When we need to upgrade from MySQL 5.7 to MySQL 8, we could choose to do an in-place upgrade or set up another MySQL 8 server(s) from the existing running MySQL 5.7 replica.

This article will explain how to set up MySQL 8 as a replica from an existing MySQL 5.7 server with Percona XtraBackup.

In my lab, we have two test nodes:

PRIMARY:  mysql57 (192.168.56.111)    with   Percona Server 5.7 and  xtrabackup 2.4 installed
REPLICA:  mysql8    (192.168.56.113)   with  Percona Server 8  and   xtrabackup 8.0 installed

0. Pre-flight check with MySQL upgrade checker utility

Let’s run the MySQL upgrade checker utility to verify whether MySQL 5.7 server instances are ready for an upgrade.

MySQL  localhost  JS > util.checkForServerUpgrade('root@localhost:3306', {"password":"####", …

This post was originally published in October 2018 and was updated in March 2023.

pt-query-digest is one of the most commonly used tools for query auditing in MySQL. By default, pt-query-digest reports the top ten queries consuming the most amount of time inside MySQL. A query that takes more time than the set threshold for completion is considered slow, but it’s not always true that tuning such queries makes them faster. Sometimes, when resources on the server are busy, it will impact every other operation on the server, and so will impact queries too. In such cases, you will see the proportion of slow queries going up. That can also include queries that work fine in general.

This article explains a small trick to identify such spots using pt-query-digest and the slow query log. pt-query-digest …