The latest from the MySQL community

If you are thinking of using ProxySQL in our Percona XtraDB Cluster environment, I’ll explain how to use ProxySQL 2 for failover tasks.

How to Test

ProxySQL uses the “weight” column to define who is the WRITER node. For this example, I’ll use the following list of hostnames and IPs for references:

+-----------+----------------+
| node_name | ip             |
+-----------+----------------+
| pxc1      | 192.168.88.134 |
| pxc2      | 192.168.88.125 |
| pxc3      | 192.168.88.132 |
+-----------+----------------+

My current WRITER node is the “pxc1” node, but how can I see who is the current WRITER? It’s easy, just run the following query:

proxysql> select hostgroup_id, comment, hostname, status, weight from runtime_mysql_servers;

This is the output: …

Throughout this tutorial for beginners you'll learn to use Laravel 6 - the latest version of one of the most popular PHP frameworks - to create a CRUD web application with a MySQL database and Bootstrap 4 styles from scratch and step by step starting with the installation of Composer (PHP package manager) to implementing and serving your application.

Note: Laravel 6 is recently released and this tutorial is upgraded to the latest version.

What is Bootstrap 4?

Bootstrap 4 is the latest version of Twitter Bootstrap which is a CSS framework that allows web developers to professionally style their web interfaces without being experts in CSS.

Bootstrap 4 is based on Flexbox and allows you to build responsive layouts with easy classes and utilities.

What is CRUD?

CRUD stands for Create, Read, Update and Delete which are operations needed in most data-driven apps that access and work with data from a …

Understanding MySQL 8.0 Group Replication Limitations to build an highly reliable MySQL Infrastructure Operations  Introduction – Redundant and fault-tolerant database systems

Most of our customers are 24*7 internet properties and their applications ( i.e. entire business operations) rely heavily on availability of respective database systems nodes, These systems going unavailable cause serious impact on reputation, customer experience and revenue. To ensure business continuity under foreseeable and unforeseeable man-made or natural disasters, the database system has to be designed and built with fault tolerance and disaster recovery capabilities, in other words the component can be removed and the system should continue to operate as expected. High availability refers to the characteristics of a system that allow the system to sustain continuous operation in the event of hardware and software failures due to natural or man …

Monitoring your MySQL database performance in real-time helps you immediately identify problems and other factors that could be causing issues now or in the future. It’s also a good way to determine which components of the database can be enhanced or optimized to increase your efficiency and performance. This is usually done through monitoring software and tools either built-in to the database management software or installed from third-party providers.

Prometheus is an open-source software application used for event monitoring and alerting. It can be used along with a visualization tool like Grafana to easily create and edit dashboards, query, visualize, alert on, and understand your metrics. ScaleGrid provides full admin access to your MySQL deployments – this makes it …

Django 3 is released with full async support!

In this tutorial series, you'll learn about Django 3 by creating a CRUD example application with database, admin access, and REST API views. We'll be using MySQL as the database system.

Throughout this beginner's tutorial for Django 3, we are going to learn to build web applications with Python and Django. This tutorial assumes no prior experience with Django, so we'll be covering the basic concepts and elements of the Django framework by emphasizing essential theory with practice.

Basically, we are going to learn Django fundamental concepts while building a simple CRM web application.

This tutorial doesn't only cover fundamental basics of Django but also advanced concepts such as how to use and integrate Django with modern front end frameworks like Angular 2+, Vue and React.

You'll learn about CRUD, database ORM, how to create API views and URLs.

…

ProxySQL and Orchestrator are usually installed to achieve high availability when using MySQL replication. On a failover (or graceful takeover) scenario, Orchestrator will promote a slave, and ProxySQL will redirect the traffic. Depending on how your environment is configured, and how long the promotion takes, you could end up in a scenario where you need manual intervention.

In this post, we are going to talk about some considerations when working with ProxySQL in combination with pt-heartbeat (part of Percona Toolkit), with the goal of making your environment more reliable.

Why Would We Want pt-heartbeat With ProxySQL?

If you have intermediate masters, the seconds_behind_master metric is not good enough. Slave servers that are attached to intermediate masters will report the seconds_behind_master relative to their own …

For Linux, the most common way to distribute software is binary packages in the rpm or deb format. Most packages are included in the official distribution repositories or 3rd party software repositories. Nevertheless, there are some cases where you need to install just a few standalone packages.   You might be able to use the local package install tools, namely dpkg or rpm, however, there are cases where packages can’t be installed due to the dependencies and you need to install all dependencies manually. It might take some time and isn’t always an easy process. But there is a solution that can help – you can create your own local repository and deploy your packages to it.

Let’s discuss how to create your local repositories to make your life easier.

RPM-Based Distributions

RPM-based operating systems work with rpm packages and the most common package manager for them is yum.   While newer …

First I want to thank everyone who attended my December 19, 2019 webinar “Top 3 Features of MySQL“. Recording and slides are available on the webinar page.

Here are answers to the questions from participants which I was not able to provide during the webinar.

Q: When do undo logs and redo logs come into play? Can you please explain the background operations of these logs?

A: These two are completely different structures.

Undo Logs

Belong to a single active transaction. It contains information on how to undo the latest change to the clustered index, performed by this transaction.

Let’s demonstrate how they work with an example.

Consider this table:

I have published enough Debezium MySQL connector tutorials for taking snapshots from Read Replica. To continue my research I wanted to do something for AWS RDS Aurora as well. But aurora is not using binlog bases replication. So we can’t use the list of tutorials that I published already. In Aurora, we can get the binlog file name and its position from its snapshot of the source Cluster. So I used a snapshot for loading the historical data, and once it’s loaded we can resume the CDC from the main cluster.

Requirements:

1. Running aurora cluster.
2. Aurora cluster must have binlogs enabled.
3. Make binlog retention period to a minimum 3 days(its a best practice).
4. Debezium connector should be able to access both the clusters.
5. Make sure you have different security …

In my previous post, I have shown you how to take the snapshot from Read Replica with GTID for Debezium MySQL connector. GTID concept is awesome, but still many of us using the replication without GTID. For these cases, we can take a snapshot from Read replica and then manually push the Master binlog information to the offsets topic. Injecting manual entry for offsets topic is already documented in Debezium. I’m just guiding you the way to take snapshot from Read replica without GTID.

Requirements:

• Setup master slave replication.
• The slave must have log-slave-updates=ON else connector will fail to read from beginning onwards.
• Debezium connector should be able to …