Recently I was asked a question: Why am I getting utf8mb4_0900_ai_ci as the default collation in MySQL 8, despite setting the server to use utf8mb4_general_ci? With the upgrade to MySQL…

The post MySQL 8 utf8mb4_0900_ai_ci collation confusion first appeared on Change Is Inevitable.

Interpreting the results and exit codes of your upgrade tests is essential for assessing the process’s outcome. In this blog, we’ll explore the significance of pt-upgrade return codes and how…

The post Understanding Return Codes of pt-upgrade: A quick guide first appeared on Change Is Inevitable.

A friend’s application started failing with MySQL causing error about timestamp columns and it needs urgent fixing from the database side. A timestamp column was not accepting the null values…

The post MySQL 8 – timestamp cannot be null and explicit_defaults_for_timestamp first appeared on Change Is Inevitable.

My last blog, Percona Utilities That Make Major MySQL Version Upgrades Easier, detailed the tools available from the Percona toolkit that assists us with major MySQL version upgrades. The pt-upgrade tool aids in testing application queries and generates reports on how each question performs on servers running various versions of MySQL.

MySQL Shell Upgrade Checker is a utility that helps in compatibility tests between MySQL 5.7 instances and MySQL 8.0 upgrades, which is part of the mysql-shell-utilities. The util.checkForServerUpgrade() function checks whether the MySQL 5.7 instance is ready for the MySQL 8.0 upgrade and generates a report with warnings, errors, and notices for preparing the current MySQL 5.7 setup for upgrading to MySQL 8.0.

We can run this Upgrade Checker Utility in the current MySQL 5.7 …

It is essential to upgrade MySQL to the most recent version. Do you believe it’s tough to test and upgrade to a newer version?

For a variety of reasons, including new features, performance advantages, bug corrections, and so on, databases with obsolete versions are vulnerable. Major version upgrades, on the other hand, can be problematic if they haven’t been extensively tested with your application, as the procedure may break it, prevent it from functioning properly, or result in performance concerns.

Let’s go through a few useful tools that can assist you with MySQL upgrades.

• pt-upgrade

The tool helps you run application SELECT queries and generates reports on how each query pattern performs on the servers across the different versions of MySQL we tested.

• …

MySQL Shell is a pretty nice piece of software. Is not just another mysql client but it is also a tool that offers scripting capabilities for JavaScript and Python. And one of the coolest things you can do with it is to check if your MySQL 5.7 server is ready for an upgrade or not. Enter: Upgrade Checker Utility.

MySQL Shell Upgrade Checker Utility

So what is it? It is a script that will check your MySQL 5.7 instance for compatibility errors and issues with upgrading. It’s important to notice the word “check”. It doesn’t fix. Just check. Fix is on you, friendly DBA (or we can happily assist with it).

But isn’t there something that already does that? Close, but no. The mysqlchk program and the –check-upgrade parameter does something similar: Invokes the CHECK TABLE …. FOR UPGRADE command. The Upgrade …

In this blog post, we’ll discuss how to set a replication from MySQL 8.0 to MySQL 5.7. There are some situations that having this configuration might help. For example, in the case of a MySQL upgrade, it can be useful to have a master that is using a newer version of MySQL to an older version slave as a rollback plan. Another example is in the case of upgrading a master x master replication topology.

Officially, replication is only supported between consecutive major MySQL versions, and only from a lower version master to a higher version slave. Here is an example of a supported scenario:

5.7 master –> 8.0 slave

while the opposite is not supported:

8.0 master –> 5.7 slave

In this blog post, I’ll walk through how to overcome the …

There were two nasty MySQL replication bugs in two different 5.6 releases that would make it difficult to upgrade slaves to MySQL 5.6 while still connected to MySQL 5.5 master. The first of those bugs is MySQL bug 72610 which affects 5.6.19. Essentially this bug is triggered when the table structure on the slave is different from the table structure on the master which leads to unnecessarily large amount of RAM usage while replicating events that affect that table. The amount of RAM used would generally be more noticeable when the replicated transaction consists of thousands of RBR events. The most common way this affects how we upgrade a replication hierarchy, is when we have the master running MySQL 5.5 and the slave running MySQL 5.6 and we have transactions involving DATETIME column(s). Tables with DATETIME columns will have different underlying structure when created on MySQL 5.5 versus when created on MySQL 5.6. Ideally you would avoid creating …

MySQL upgrades are necessary tasks and we field a variety of questions here at Percona Support regarding MySQL upgrade best practices. This post highlights recommended ways to upgrade MySQL in different scenarios.

Why are MySQL upgrades needed? The reasons are many and include: Access to new features, performance benefits, bug fixes…. However, MySQL upgrades can be risky if not tested extensively beforehand with your application because the process might break it, prevent the application from functioning properly – or performance issues could arise following the upgrade. Moreover, I suggest keeping an eye on new releases of MySQL and Percona Server – check what has changed in the …

  Do you know how to do rolling maintenance on your database hosts so you can make changes without stopping applications? How about upgrading schema and applications themselves? Tungsten clusters have a host of features that can help you with everything from basic administration to complex application upgrades. This webinar shows you the different types of administration you need to perform, and