When we explore strategies to scale our MySQL-based database layer, we realize that there are many different options. As opposed to proprietary solutions, open-source products nourish themselves from their communities and novel architectures or enhanced versions are generated, often incorporating other open source technologies. MySQL is not an exception.

Other players build completely different engines aiming to mitigate some of MySQL well-known weaknesses, but still support its wire protocol, with the challenge of sacrificing as little compatibility as possible.

In this white paper, we briefly discuss the scale-up vs scale-out dilemma, to then review the different scale-out strategies. We are also going to go over some of the most common MySQL architectures and products with horizontal scaling in mind.

Finally, we will share some guidelines to …

Sometimes, the MySQL Optimizer chooses a wrong plan, and a query that should execute in less than 0.1 second ends-up running for 12 minutes !  This is not a new problem: bugs about this can be traced back to 2014, and a blog post on this subject was published in 2015.  But even if this is old news, because this problem recently came yet again to my attention, and because this is still not fixed in MySQL 5.7 and 8.0, this is a subject worth writing about.

The MySQL Optimizer

Before looking at the problematic query, we have to say a few words about the optimizer.  The Query Optimizer is the part of query execution that chooses the query plan.  A Query Execution Plan is the way MySQL chooses to execute a specific query.  It …

MariaDB 10.4 has being declared GA, and few presentations on Galera4 in the last conferences were hold.

So, I thought, it is time to give it a try and see what is going on.

It is not a secret that I consider the Codership guys my heroes, and that I have push for Galera as solid and very flexible HA solution, for many years.

Given that my first comment is that it was a shame to have Galera4 available only in MariaDB, I would have preferred to test the MySQL vanilla version for many reasons, but mainly because the MySQL/Oracle is and remain the official and main line of the MySQL software, you like it or not, and as such I want to see how the Galera4 behave with that. Anyhow Codership state that the other versions will be out AFTER the summer, and I hope this will be true.

To test the new version given I do not have the vanilla MySQL, I decide to use the other distribution coming from Percona. At the end the test …

Optimal Indexing for Performance – How to plan Index Ops. ? 

An index or database index is a data structure which is used to quickly locate and access the data in a database table. Indexes are created on columns which will be the Search key that contains a copy of the primary key or candidate key of the table. These values are stored in sorted order so that the corresponding data can be accessed quickly (Note that the data may or may not be stored in sorted order). They are also Data Reference Pointers holding the address of the disk block where that particular key value can be found. Indexing in database systems is similar to what we see in books. There are complex design trade-offs involving lookup performance, index size, and index-update performance. Many index designs exhibit logarithmic (O(log(N))) lookup performance and in some applications it is possible to achieve flat (O(1)) performance. Indices can …

You may have noticed that in many of my demos, I disable firewall and SELinux (I even use --initialize-insecure sometimes ). This is just to make things easier… But in fact enabling iptables and SELinux are not complicated.

Firewall

These examples are compatible with Oracle Linux, RedHat and CentOS. If you use another distro, the principle is the same.

For the firewall, we need first to allow incoming traffic to MySQL and MySQL X ports: 3306 and 33060:

# firewall-cmd --zone=public --add-port=3306/tcp --permanent
# firewall-cmd --zone=public --add-port=33060/tcp --permanent

If you don’t plan to restart the firewall, you just need to run the same commands without --permanent to make then immediately active.

Then we need to allow the Group Replication’s communication port. This is usually 33061 but it can be configured in …

You have seen in this previous post, that since 8.0.17, it’s now possible to query the MySQL Router using its REST API.

Additionally, we also saw in this post, that since 8.0.17, we are now able to write extensions to MySQL Shell using the Extension Framework.

Let’s combine both and see how we can integrate the MySQL Router’s REST API in the Shell.

I’ve created an extension in ext.router that creates a MySQL Router Object.

The new extension, as a method to create the object:

This is an example that illustrates how to create a MySQL Router Object, as you can see you can pass the password directly as parameter but it’s not recommended in interactive mode. It’s …

The Question Recently, a customer asked us:

How would we manually move the relay role from a failing node to a slave in a Composite Tungsten Cluster passive site?

The Answer The Long and the Short of It

There are two ways to handle this procedure manually when the usual switch command fails to work as expected. One is short and reasonably automated, and the other is much more detailed and manual.

Of course, the usual procedure is to just issue the switch command in the passive cluster:

use west
set policy maintenance
switch
set policy automatic

The below article describes what to do when the switch command does not move the relay role to another node.

SHORT

Below is the list of cctrl commands that would be run for the basic, short version, which (aside from handling policy changes) is really only three …

From Drupal’s website, we can see that now the support of MySQL 8 is ready.

I just tested it and it works great !

The only restriction is related to PHP and the support for the new authentication method in php-mysqlnd.

In this previous post, I was happy because it was included in PHP 7.2.8, but this has been reverted back since then. Currently none of the latest version of PHP 7.x is supporting this authentication method.

We can easily verify this, first with the PHP version provided by default in Oracle Linux 8:

# php -i | grep "Loaded plugins\|PHP Version " | tail -n2
PHP Version => 7.2.11
Loaded plugins => mysqlnd,debug_trace,auth_plugin_mysql_native_password, …

I have already posted some time ago a post related to the same topic (see here).

Today, I want to explain the easiest way to create an asynchronous replica from an existing MySQL instance, that this time has already data !

The Existing Situation and the Plan

Currently we have a MySQL server using 8.0.17 and GTID enabled on mysql1. mysql2is a single fresh installed instance without any data.

The plan is to create a replica very quickly and using only a SQL connection.

Preliminary Checks

First we verify that mysql1 has GTID enabled. If not we will enable them:

mysql> select @@server_id,@@gtid_mode,@@enforce_gtid_consistency;
+-------------+-------------+----------------------------+
| @@server_id | @@gtid_mode | @@enforce_gtid_consistency | …

Join Percona Support Engineer Vinicius Grippa as he presents his talk “Enhancing MySQL Security” on Thursday, July 25th, 2019 at 6:00 AM PDT (UTC-7) / 9:00 AM EDT (UTC-4).

Register Now

Security is always a challenge when its comes to data. Moreso, regulations like GDPR add a whole new layer on top of it, with rules more and more restrictive to access and manipulate data. Join us in this presentation to check security best practices as well as traditional and new features available for MySQL, including features coming with the new MySQL 8.

In this talk, DBAs and sysadmins will walk through the security features available on the OS and MySQL. These features include:

• SO security
• SSL
• ACL
• TDE
• Audit Plugin
• MySQL 8 features (undo, redo, and binlog …