Many of us, old MySQL DBAs used Seconds_Behind_Source from SHOW REPLICA STATUS to find out the status and correct execution of (asynchronous) replication.

Please pay attention of the new terminology. I’m sure we’ve all used the old terminology.

However, MySQL replication has evolved a lot and the replication team has worked to include a lot of useful information about all the replication flavors available with MySQL.

For example, we’ve added parallel replication, group replication, … all that information is missing from the the good old SHOW REPLICA STATUS result.

There much better ways to monitoring and observing the replication process(es) using Performance_Schema.

Currently in Performance_Schema, there are 15 tables relating to replication instrumentation:

+------------------------------------------------------+
| …

After having explained how to build MySQL 8 (MySQL 8.0 and MySQL 8.1) on OL9 and OL7, this episode of the series will cover how to build MySQL 8 on Oracle Linux 8 (OL8) and compatible (EL8, CentOS 8, …).

My build machine is a VM.Standard.E4.Flex instance on OCI having 8 OCPUs and 128GB of ram with Oracle Linux 8.8. The machine has also a block volume of 50GB attached and mounted in /home/opc/rpmbuild:

Getting the source RPM

To get the source RPM, you need first to install the MySQL Community’s repo:

$ sudo dnf install -y https://dev.mysql.com/get/mysql80-community-release-el8-7.noarch.rpm

But comparing to OL7 and OL9, this is maybe the most complicate process if you are not aware …

Following our discussion with Simon about compiling MySQL 8.0.34 and 8.1.0 for OL9 (RedHat and CentOS Stream as well), see this blog post, we realized that compiling the latest MySQL 8.x on OL7 (EL7) wasn’t very simple either.

After soliciting the MySQL release engineer team, I was able to compile MySQL correctly from its src rpm.

Let me share the various steps with you.

My build machine is a VM.Standard.E4.Flex instance on OCI having 4 OCPUs and 64GB of ram with Oracle Linux 7.9. The machine has also a block volume of 50GB attached and mounted in /home/opc/rpmbuild.

Getting the source RPM

To get the source RPM, you need first to install the MySQL Community’s repo:

$ sudo yum install -y …

There are plenty GUI and Web application used to monitor a MySQL server. But if you are long time MySQL DBA, you might have used (and abused) Innotop !

I loved it ! And I even became maintainer of it. This particular task became more and more complicated with the different forks and their differences. Also, let’s be honest, Perl saved my life so many times in the past… but this was in the past. These days, having Perl on a system is more complicated.

But Innotop is still very popular in the MySQL world and to help me maintaining it, I would like to welcome a new member in the maintainer group: yoku0825. Tsubasa Tanaka has been a long time user and contributor of Innotop and I’m sure will keep to good work.

I’ve tried to find an alternative to Innotop, and I even wrote my own clone in Go …

After discussing with Simon about some issues when trying to recompile MySQL 8.0.34 on CentOS 9 (see #111159), I also tried it and indeed some dependencies are not listed when compiling via the source RPM.

Let’s see how to recompile the two latest versions of MySQL (8.0.34 and 8.1.0) using the source RPMs.

I use Oracle Linux 9 as build machine.

Getting the source RPM

To get the source RPM, you need first to install the MySQL Community’s repo:

$ sudo dnf install …

On the Internet, you can get a lot of advice from almost anywhere when you’re looking for information on how to do your DBA job.

My blog is one of these sources of advice, and depending on the source, we generally trust the advice more or less.

But sometimes advice doesn’t take the whole picture into account, and even if it comes from a recognized authority, it can lead to more or less serious problems.

Let’s consider the following situation:

We have an InnoDB ReplicaSet with 1 replication source (primary) and 2 replicas:

 JS > rs.status()
{
    "replicaSet": {
        "name": "myReplicaSet", 
        "primary": "127.0.0.1:3310", 
        "status": "AVAILABLE", 
        "statusText": "All instances available.", 
        "topology": {
            "127.0.0.1:3310": {
                "address": "127.0.0.1:3310", 
                "instanceRole": "PRIMARY", 
                "mode": "R/W", …

To continue our journey to Moodle on Oracle Cloud Infrastructure using Ampere compute instances and MySQL HeatWave Database Service [1] [2], in this article we will see how to scale our architecture using multiple Moodle instances, High Availability for the Database and Read Scale-Out.

This is the architecture we will deploy:

The same principles can be applied to other projects, not just Moodle.

Multiple Compute Instances & MySQL HeatWave High Availability

The first step is to use again the Stack to deploy the initial resources. We must insure that we use a MySQL Shape that has at least 4 OCPUs …

In the previous post, we saw how to quickly deploy Moodle to Oracle Cloud Infrastructure on Ampere compute instances and using MySQL HeatWave.

In this post, we will explore some other features and the benefits of running on OCI and MySQL HeatWave to extend our architecture dedicated to Moodle in the Cloud.

Read Replicas

Moodle natively offers the possibility of distributing the load between reads and writes. When using MySQL HeatWave Database Service, adding read replicas is also a very easy task. Let’s see how we can benefit from it.

To be able to use MySQL HeatWave Read Replicas, the MySQL shape must have at least 4 OCPUs.

Let’s modify the moodle stack and deploy it again but this time we choose a bigger shape for MySQL:

When everything is ready, …

If you want to deploy Moodle on OCI, you can use Ampere compute instances as application server and MySQL HeatWave Database Service to store the data.

Depending on your requirements, MySQL HeatWave can provide High Availability and Query Acceleration.

In this post, we will see the easiest and fasted way to deploy the following basic architecture:

In OCI to quickly deploy an architecture and all the required resources, it’s recommended to use a Stack (Terraform recipes and modules).

So deploy all the resources we need (VCN, Subnets, Security Lists, Internet Gateways, Compute Instances…) we just need to click on the following button:

…

Yesterday, I published an article explaining how to easily deploy Apache Superset on OCI using MySQL HeatWave Database Service.

There are some people not using the automation or not using MySQL HeatWave Database Service on OCI but want to still use Superset with MySQL 8.0.

In this blog, we will see how to fix eventual errors when performing the installation manually.

SQL Alchemy Dialect Configuration

When using MySQL 8.0, in Superset’s config file, you need to specify the SQLAlchemy URI like this:

SQLALCHEMY_DATABASE_URI = 'mysql+mysqlconnector://<user>:<password>@<host>:<port>/<superset_schema>'

It is important to specify the database backend and dialect: mysql+mysqlconnector.

Of course you need to install the MySQL …