Overview The Skinny

When it comes to zero downtime, proxies are the first line components of a cluster.

In order to achieve High Availability (HA) for MySQL, MariaDB and Percona Server, a commonly deployed setup consists of configuring load balancers (hardware or software) on top of those proxies.

A Strong Architecture How is Maintenance Made Possible?

With this proxy + load balancer architecture, server maintenance is made possible on any of the proxy hosts, as follows:

• the proxy is stopped
• the load balancer detects the dead proxy and removes it from the pool
• new connection requests go to live proxies

The Problem What Happens to Existing Sessions?

But wait… even though new connections are re-routed correctly, what happens …

Just a reminder for the shows we are attending this week: 

• Hong Kong OpenSource Conference (HKOS), Hong Kong, Jun 14-15, 2019

  • MySQL as Silver sponsor will have a MySQL booth & MySQL track on the second day morning.
• SouthEast Linux Fest (SELF), Charlotte, US, Jun 14-16, 2019
  • MySQL as Diamond sponsor will have a MySQL booth as well as three MySQL talks given by David Stokes, the MySQL Community Manager as follows:
    • Securing your SQL and NoSQL Databases, 4:00-5:00pm on Jun 14.
    • How Do You Get Your Book Published?, 11:30-12:30pm on Jun 15.
    …

In the previous blog post, we showed you some basic steps to deploy and manage a standalone MySQL server as well as MySQL Replication setup using the MySQL Puppet module. In this second installation, we are going to cover similar steps, but now with a Galera Cluster setup.

Galera Cluster with Puppet

As you might know, Galera Cluster has three main providers:

• MySQL Galera Cluster (Codership)
• Percona XtraDB Cluster (Percona)
• MariaDB Cluster …

Since 8.0.16, MySQL Server supports a --validate-config option that enables the startup configuration to be checked for problems without running the server in normal operational mode.
--validate-config can be used any time, but is particularly useful after an upgrade, to check whether any options previously used with the older server are considered by the upgraded server to be deprecated or obsolete.

The post Check the MySQL server startup configuration first appeared on dasini.net - Diary of a MySQL expert.

Background The Skinny

Performing schema changes often requires extended downtime for applications. This is due to MySQL needing to rebuild tables for common schema change operations. Tools like pt-online-schema-change have been written to try to overcome the downtime associated with schema changes, however they are complex and put a high load on the database. Amazon’s Aurora improves some schema changes operations, but still requires a table rebuild for common operations like adding a column using before or after, or simply to add a column with a default value. Rebuilding a table with millions of rows can take hours and prevent writes to that table the entire time.

How Can Tungsten Clustering Keep Applications Running? How Does It All Work?

…

This blog is aimed at explaining an overview of cross replication between PostgreSQL and MySQL, and further discussing the methods of configuring cross replication between the two database servers. Traditionally, the databases involved in a cross replication setup are called heterogeneous databases, which is a good approach to move away from one RDBMS server to another.

Both PostgreSQL and MySQL databases are conventionally RDBMS databases but they also offer NoSQL capability with added extensions to have the best of both worlds. This article focuses on the discussion of replication between PostgreSQL and MySQL from an RDBMS perspective.

An exhaustive explanation about internals of replication is not within the purview of this blog, however, some foundational elements shall be discussed to give the audience an understanding of how is replication configured between database servers, advantages, limitations and perhaps some known use …

Por si no se hubiera visto o promocionado lo suficiente, quería compartir la lista de webcasts en Español que ya hay disponible en On Demand webinars en el apartado de News & Events en mysql.com:

https://www.mysql.com/news-and-events/on-demand-webinars/#es-20-0

Sobre 1 hora de duración cada una, aquí tenéis algunos ejemplos:

MySQL InnoDB Cluster: Una introducción y Demo

MySQL, NoSQL, JSON, JS, Python: Document Store. (+demo)

MySQL …

How to properly shutdown MySQL before any maintenance activity
We might have different scenarios once we need to stop MySQL service before performing either server or database activity like patching/upgrade.  
Before performing such activity, we need to make sure that we stop MySQL service properly to avoid any unforeseen crashes once our maintenance activity complete and MySQL service is started. 
Here I would like to share the below steps which should be performed and take care to properly stop MySQL service. 

Step 1: Ensure we don't have any long-running queries. Manually verify by checking the processlist. show …

Throughout this php tutorial for beginners by example, we'll learn to build web applications with PHP 7 for server and MySQL for database access and storage (and also Angular 8 for front-end). In this tutorial, we'll create a CRUD (Create, Read, Update and Delete) example application with a MySQL database. We'll also see how we can build modern PHP applications with a frontend UI built with the latest Angular 8 framework.

Introducing PHP for Angular 8 developers Angular 7|8 with PHP and MySQL RESTful CRUD Example & Tutorial Angular 7|8 with PHP: Consuming a RESTful CRUD API with HttpClient and Forms

PHP Tutorial

How Would you Use Angular 8 with PHP?

How to Connect Angular 8 with PHP

Introducing PHP 7

PHP Tutorial Prerequisites

PHP Scripts

Why Using PHP?

PHP Basics

Conclusion PHP vs. Python & Django

How Would you Use Angular 8 with PHP?

…

Do you know that it’s possible to get information from the CPUs of your MySQL Server from SQL ?

If you enable the status for the  INNODB_METRICS table in INFORMATION_SCHEMA, you will be able to query CPU information.

First, check if those status are enabled:

MySQL> SELECT name, subsystem, status 
FROM INFORMATION_SCHEMA.INNODB_METRICS where NAME like 'cpu%';
+---------------+-----------+----------+
| name          | subsystem | status   |
+---------------+-----------+----------+
| cpu_utime_abs | cpu       | disabled |
| cpu_stime_abs | cpu       | disabled |
| cpu_utime_pct | cpu       | disabled |
| cpu_stime_pct | cpu       | disabled |
| cpu_n         | cpu       | disabled |
+---------------+-----------+----------+
5 rows in set (0.00 sec)