In MySQL 8.0 we introduced a totally new design for InnoDB REDO Log management. The main difference was about implementing a lock-free solution for user threads, and use dedicated REDO threads for all background IO write work.

for more details, see an excellent and very detailed article by Pawel : https://dev.mysql.com/blog-archive/mysql-8-0-new-lock-free-scalable-wal-design/

However, over a time we also added an option to let users to switch REDO threads=OFF to enforce REDO log processing efficiency in some particular cases. Unfortunately this feature created a lot of confusions for MySQL users, and many ones interpreted this in different ways, providing different and sometimes opposite advices, etc..

My main advice will be always : test each feature yourself and within your …

TL;DR: Make sure to run “SET persist_only disabled_storage_engines=’MyISAM’, persist sql_generate_invisible_primary_key=ON;” on all instances and restart each one in your MySQL InnoDB Cluster.

Ok, what does “safe from naughtiness” mean?:
– Anyone creating tables that aren’t InnoDB, as this doesn’t make sense, after all, it is an “InnoDB” cluster.
– Making sure all tables have a Primary Key (invisible or not).
– Making sure that my (invisible) primary keys are visible to the cluster as it will rightfully complain if they aren’t!

This basically means that once you’ve got it all up and running you won’t run into those horrible situations whereby someone, somewhere, creates a MyISAM table that didn’t have a Primary Key and thus leave you with a broken cluster.

Eg.

MySQL rtnode-01:3306 ssl JS > vlc.status()
{
 "clusterName": "VLC",
 "clusterRole": "PRIMARY", …

Now this is far from being any observability manual for your InnoDB Cluster and let alone go into everything MySQL Shell API Admin, or the collectDiagnostics utility. You can also use the default javascript commands that we all know and love via dba.getCluster() and so on, but here’s a different take.

I just want to share something I’ve been playing with to pull out some key info from mycluster. Hope it helps someone else out there.

General setup:

select cluster_id, cluster_name, description, cluster_type, primary_mode, clusterset_id
from mysql_innodb_cluster_metadata.clusters;

Members of our cluster:

select * from …

Yesterday, MySQL 8.4, the very first LTS version of MySQL was released.

A lot of deprecations have finally been removed, and several InnoDB variable default values have been modified to match current workloads and hardware specifications.

The default value of 20 InnoDB variables has been modified!

Let’s have a look at those variables and explain the reason for such modification:

innodb_buffer_pool_in_core_file

MADV_DONTDUMP is a macro supported in Linux 3.4 and later, (“sys/mman.h” header file is present and contains the symbol MADV_DONTDUMP, a …

In MySQL 8.0.12, we introduced a new algorithm for DDLs that won’t block the table when changing its definition. The first instant operation was adding a column at the end of a table, this was a contribution from Tencent Games.

Then in MySQL 8.0.29 we added the possibility to add (or remove) a column anywhere in the table.

For more information, please check these articles from Mayank Prasad : [1], [2]

In this article, I want to focus on some dangers …

Percona XtraBackup (PXB) version 8.0.28 supports taking backups for the encrypted tables in your MySQL database using the AWS Key Management Service. For setting up data-at-rest encryption using AWS key management service, please see Configuring Keyring for Encryption Using AWS Key Management Service in Percona Server for MySQL.In this blog post, we will discuss how […]

Back again, now with MySQL installs. And this means using the MySQL repository this time around.

I’ve been installing and configuring InnoDB Clusters and ClusterSets and thinking about the Ansible and Terraform users amongst us, maybe one-liners might help someone out there.

So, what about if I share how to install the MySQL repo, install the MySQL instance, create an InnoDB Cluster, add a MySQL Router, create a ClusterSet, make sure the Router is ClusterSet-aware, and then test it out. And all via one-liners.

First up, obrigado Miguel for https://github.com/miguelaraujo/ClusterSet-Demo.

To simplify the command execution sequence, these sections aim to help summarize the technical commands required to create the whole platform. And on a default path & port configuration, to ease operational deployments for all those 000’s of …

Recently during the Swedish MySQL User Group (SMUG), I presented a session dedicated to MySQL InnoDB Primary Keys.

I forgot to mention a detail that many people are not aware, but Jeremy Cole has pointed out.

Primary Key always included in secondary indexes at the right-most column

When we define a secondary index, the secondary index includes the Primary Key as the right-most column of the index. It’s silently added, meaning that it’s not visible but it’s used to point back to the record in the clustered index.

This is an example with a table having a Primary Key composed of multiple columns:

CREATE TABLE `t1` (
`a` int NOT NULL,
`b` int NOT NULL, 
`c` int NOT NULL,
`d` int NOT NULL,
`e` int …

In this blog post, we will discuss how to validate at the operating system level the effects of changing the innodb_flush_method to variations other than the default (particularly for O_DIRECT which is most commonly used) and the use of innodb_use_fdatasync.IntroductionFirst, let’s define what the innodb_flush_method parameter does. It dictates how InnoDB manages the flushing of data […]

In the world of data backup and security, physical backups play an extremely important role. Physical backup methods are faster than logical because they involve only file copying without conversion. This type of backup is suitable for large, important databases that need to be recovered quickly when problems occur.

Physical backups are the backups that consist of raw copies of the directories and files that store database contents. In addition to databases, the backup can include any related files, such as log or configuration files. Now, since backup speed and compactness are important for busy, important databases, Percona’s open source physical backup solution – Percona XtraBackup (PXB), takes into account all these aspects and benefits MySQL world with its exceptional capabilities!

This blog post will walk you through how PXB …