Recently I posted about checkpointing in MySQL, where MySQL showed interesting “wave” behavior.

Soon after Dimitri posted a solution with how to fix “waves,” and I would like to dig a little more into proposed suggestions, as there are some materials to process.

This post will be very heavy on InnoDB configuration, so let’s start with the basic configuration for MySQL, but before that some initial environment.

I use MySQL version 8.0.21 on the hardware as described here. 

As for the storage, I am not using some “old dusty SSD”, but production available Enterprise-Grade Intel SATA SSD …

     VIEWs have been a handy feature of MySQL for many years but do you know about the WITH CHECK OPTION clause?  The WITH CHECK OPTION clause is used for a updatable views to prohibit the changes to those views that would produce rows which are not included in the defining query.

    VIEW Definition     Since a lot of SQL novices read my blog, I'd like to start with the definition of a view "Views are stored queries that when invoked produce a result set. A view acts as a virtual table" according the MySQL Manual.
SQL > CREATE VIEW x_city AS              SELECT     Name,                         …

 I have two talks this week on MySQL 8.0 that you can attend virtually. And another session that is one line also plus an article.  Busy week!

First is a follow on to a earlier session I did for the good folks at cPanel want you to register here for MySQL 8.0 changes for DBAs and DevOps on August 12th, 2020  at 2PM CDT. The first talk was mainly for developers and this time I am, heavily covering InnoDB Cluster and features that are of more interest to the folks who keep MySQL instances running.

MergePHP - New MySQL Features That You May Have Missed is on Thursday August 13th at 7:00 Eastern . This is an exciting combination of three MySQL user groups who have joined together for a virtual meeting.

Then on Friday the 14th I am panelist for the …

A student question: Does JavaScript make context switching for web-based applications obsolete? Wow! I asked what that meant. He said, it means JavaScript replaces all other server-side programming languages, like PHP, C#, or Python. I asked the student why he believed that. His answer was that’s what two interviewing managers told him.

I thought it would be interesting to put the idea to a test. Below is a Node.js script that acts as a utility that queries the MySQL database with substitution variables in query. It also returns a standard out (stdout) stream of the MySQL query’s results. It also supports three flag and value pairs as arguments, and optionally writes the results of the MySQL query to a log file while still returning result as the stdout value. All errors are written to the standard error (stderr) stream.

The Node.js solution is completely portable between Windows …

Sometimes, you just half to chuckle. A couple folks felt that I didn’t give enough information in my post showing how to configure a small Node.js application that could access a MySQL database. Specifically, they wanted me to explain the following:

1. Configure your Express.js and MySQL development in a single Node.js application.
2. How to convert the list of RowDataPacket objects as elements of data, which is really just simple JavaScript knowledge.
3. How to bind variables into the query.

Like the other blog post, this one assumes you’ve performed a global install of Node.js on a Linux server. If you’re unfamiliar with how to perform a global Node.js installation, I cover how to do it in this …

These are my notes for creating a small Node.js application that queries a MySQL database. The post will show you how to:

1. Configure your Node.js development directory.
2. Build a small application to test a MySQL connection.
3. Build a small application that connects to the MySQL database and queries data.

This blog post assumes you’ve performed a global install of Node.js on a Linux server. If you’re unfamiliar with how to perform a global Node.js installation, I cover how to do it in this earlier blog post.

Before you write the Node.js applicaiton, you need to setup a db developer directory. Then, create a node_modules symbolic link to the /usr/local/lib/node_modules directory in the db directory. You can use the following command …

In April, when I updated from MySQL 8.0.17 to MySQL 8.0.19, I found that my Java connection example failed. That’s because of a change in the JDBC driver, which I blogged about then. Starting yesterday, I began updating a base Fedora 30 configuration again to MySQL 8.0.20. I wrote a testing program for the Java JDBC file last time, and when I ran it this time it told me that I didn’t have the JDBC driver installed, or in the $CLASSPATH. My Java diagnostic script, MySQLDriver.java, returned the following error message:

Error: Could not find or load main class MySQLDriver

The Java JDBC test program code is in the prior post. It simply loads the user, password, database, host, and port statically for my student …

After I updated a Fedora 30 instance, I could no longer connect to the MySQL database. An attempt to connect raised the following error:

Error: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

My guess was correct, the mysqld.service got removed during the update (a synonym for upgrade). So, I ran the following command as a sudoer user:

sudo systemctl enable mysqld.service

It creates the following symbolic link:

Created symlink /etc/systemd/system/multi-user.target.wants/mysqld.service → /usr/lib/systemd/system/mysqld.service.

That would start the MySQL Daemon (mysqld) on the next restart of the OS. However, I didn’t want to restart to have access to the service. I simply started it with the following command:

sudo systemctl start mysqld.service

Then, I could connect to the MySQL database. As always, …

MySQL Backup and Disaster Recovery Webinar (Thursday, June 18, 2020 – 06:00 PM to 07:00 PM PDT)

There can be several reasons for a MySQL database outage: hardware failure, power outage, human error, natural disaster etc. We may not be able prevent all the disaster from happening but investing on a robust disaster recovery plan is very important for building fault-tolerant database infrastructure operations on MySQL.  Every MySQL DBA is accountable for developing a disaster recovery plan addressing data sensitivity, data loss tolerance and data security. Join Shiv Iyer, Founder and Principal of MinervaDB to lean about the best practices for building highly reliable MySQL DR strategy and operations on Thursday, June 18, 2020 – 06:00 PM to 07:00 PM PDT. Building DR for a high traffic MySQL database infrastructure means deep understanding of multiple backup strategies and choosing optimal ones which are best suited for performance …

Just recently, I have been asked to look into what a Disaster Recovery site for InnoDB Cluster would look like.

If you’re reading this, then I assume you’re familiar with what MySQL InnoDB Cluster is, and how it is configured, components, etc.

Reminder: InnoDB Cluster (Group Replication, Shell & Router) in version 8.0 has had serious improvements from 5.7. Please try it out.

So, given that, and given that we want to consider how best to fulfill the need, i.e. create a DR site for our InnoDB Cluster, let’s get started.

Basically I’ll be looking at the following scenario:

InnoDB Cluster Source site with a Group Replication Disaster Recovery Site.

Now, just before we get into the nitty-gritty, here’s the scope.

Life is already hard enough, so we want as much automated as possible, so, yes, InnoDB Cluster gets some of that done, but there are other parts we will still have …