This article is the second part of our journey to WordPress and MySQL 8.0 High Availability on OCI. The first part can be read here.

We ended part I with one webserver hosting WordPress. This WordPress was connecting locally to MySQL Router using HyperDB add-on. This add-on allows to split the reads & writes on MySQL Servers using replication. And finally we had one MySQL InnoDB ReplicaSet of two …

Today’s article is again related to WordPress and MySQL 8.0. We will see how we can setup MySQL InnoDB ReplicaSet and configure WordPress to split the load using both MySQL Instances: we will split reads and writes between the Primary and the Secondary member of our ReplicaSet.

This will be the first part of our journey to achieve HA for our WordPress site on OCI and using all MySQL Servers we have deployed. We don’t want to have a server idle just waiting to take over in case of an incident.

MySQL InnoDB ReplicaSet

First some words about MySQL InnoDB ReplicaSet.

The ease of use of …

As you know, today, MySQL 8.0.20 has been released. I started this new thread category with 8.0.19 (see this post).

A late thanks to Guoji Ma, for a contribution to bug #95801 “show create table output can’t be executed” that was used as inspiration for the actual fix that was pushed in MySQL 8.0.18.

MySQL 8.0.20, includes contributions from Daniel Black, Cai Yibo, Jericho Rivera, Matti Sillanpää, Nick Pollett, Bruce Feng, Kamil Holubicky, Facebook.

Thank you all for your great contributions. MySQL is an Open Source project, GPL, and we accept contribution of course. Sometimes it’s also good to remind it

Here is the list of the contributions above:

• Impossible WHERE for a!=a, a<a, …

Let’s continue our series of using OCI to install popular Open Source programs with MySQL 8.0. After WordPress, Drupal, it’s not the Moodle’s turn!

This is a request from my Japanese colleague Machiko

We will use two different compute instances:

• the application server (apache, PHP and Moodle)
• the database server (MySQL 8.0)

The application server will be reachable from the Internet on port 22 (ssh) and 80 (http). The database server won’t be reachable from outside, we will have to use the application server as jumphost to install the server.

This is an overview of the proposed architecture:

Deploying 2 compute instances

The first step is to install 2 compute instances, one in the Public Subnet and one in the Private Subnet.

We first start with the application server (called myMoodle):

As the second instance will be located …

Last Tuesday, it was the very first session of DB AMA, Morgan Tocker made a nice presentation of MySQL Performance_Schema and illustrated it with some nice queries to get Meta et Data Locks.

As those queries were not that simple to write or at least to remember, I thought it might be a good idea to add them to MySQL Shell, the best MySQL DBA Tool !

I’ve then added a new method to the check plugin: getLocks().

Let’t see it in action:

As you can see, this is a small extension that can offers you a better view of what’s locked per transaction.

You can find several MySQL Shell Extension directly on github: …

In the previous post, we setup a Drupal website with MySQL as backend on a different compute instance in a different subnet.

Today we will increase the High Availability of our Database by transforming this single MySQL instance into a MySQL InnoDB Cluster!

The architecture will be the following:

We will use 2 different Availability Domains (AD), of course we could have used 3, it’s up to you.

We will install MySQL Router on the Application Server as advised, and we will modify our Drupal’s configuration to connect locally on the R/W port of the MySQL Router.

You will see that this is very easy to achieve, the most …

My previous post related on how to install WordPress on Oracle Cloud seemed to be very popular. To continue the exploration of OCI, today we will install Drupal.

This time, even if it’s possible to use the Free Trier like in the WordPress post, I will use a pay account to have the possibility to split the Web Server and the Database into two different subnets. Both instances will have their own subnet and only the Webserver will be reachable directly from the Internet. MySQL will be installed on a private subnet that could reach Internet only via a NAT gateway.

This is an overview of the proposed architecture:

At the end of the blog you will also be able to see this process in video.

…

Today we will see how to install WordPress in Oracle Cloud (OCI).

We will use Oracle Cloud’s Free Trier and deploy 2 compute instances:

• the webserver (apache, PHP and WordPress)
• the database server (MySQL 8.0)

We will use one public IP to reach our site and our two servers will communicate using their own private network:

Deploying 2 compute instances

Let’s start by creating 2 compute instances:

We will use the Oracle Linux 7.7 on Micro Instances:

As I am in Belgium, I use the Frankfurt datacenter.

When our instances are deployed, we can find the public IP of one of them. This is the one we will use as webserver (you can free the public IP on the other one, the MySQL one):

At the creation, we entered a ssh key to access …

Of course MySQL 8.0.19 that was released on 13th January 2020 also includes Community Contributions. But before talking about them, I would like to thanks Jesper for having started this MySQL Releases Contributions thread. I’ll try to keep his good work on that topic from now.

So, MySQL 8.0.19 includes contributions from Facebook, Satya Bodapati, Nikolai Kostrigin and Olekasandr Peresypkin.

Please note that this list might not be exhaustive as it’s currently a manual process for me to link the contributions with the current release. I will try to improve this in the future.

Here are those contributions:

• Innodb_system_rows_read, Innodb_system_rows_inserted, …

As you know, Oracle Cloud Infrastructure (aka OCI) becomes more and more popular. You can find OCI data centers almost everywhere and the price is very attractive.

Something very interesting is the possibility to have different availability domains but also different fault-domains in the same availability one !

Oracle provides a lot of modules to deploy your architecture on OCI using Terraform. Those are called oracle-quickstart repos. You can find them on Github.

There is an official Reference Architecture for MySQL InnoDB Cluster in OCI that I encourage you to read before deploying your MySQL HA solution …