Slave election is a popular HA architecture,  first MySQL MariaDB toolkit to manage switchover and failover in a correct way was introduce by Yoshinori Matsunobu into MHA.

Failover and switchover in asynchronous clusters require caution:

- The CAP theorem need to be satisfy. Getting strong consistency, require the slave election to reject transactions ending up in the old master when electing the candidate master.

- Slave election need to take care that all events on the old master are applied to the candidate master before switching roles.

- Should be instrumented to found a good candidate master and make sure it's setup to take the master role.

- Need topology detection, a master role can't be pre defined, as the role …

Setting up environments, starting processes, and monitoring these processes on multiple machines can be time consuming and error prone - stale settings from previous test runs, wrong configurations, wrong commands, package conflicts, etc.. quite a few things can go wrong. If you are using Galera Cluster, you would probably want application developers to have a proper development environment on their local computers. Proper here means testing your code on a local Galera Cluster, not on a single instance MySQL. Galera Cluster differs from a single instance MySQL, so this allows you to catch these differences early in the project. But how can you quickly roll out a mini test clusters to your application developers, without having them waste time setting these up? This is where Vagrant comes in.

Vagrant is a system that allows you to easily create and move development environments from one machine to another. Simply define what type of VM you …

• La «Database Excellence Academy» offre gratuitement une formation pratique aux jeunes diplômés
• Le partenariat contribue à atténuer le manque de main d’œuvre informatique qualifiée en Suisse

Delémont/Neuchâtel, 22.01.2015. La SSII suisse dbi services et la Haute école de gestion Arc à Neuchâtel (HEG Arc) viennent de lancer un projet d’intégration des jeunes informaticiens à la vie d’entreprise: Proposée gratuitement, la «Database Excellence Academy» va permettre à cinq jeunes diplômés en Informatique de gestion de participer à une série de formations pratiques de 3 à 4 jours portant sur les technologies de bases de données Oracle, Microsoft SQL Server et MySQL. Il s’agit d’ateliers assurés par des experts reconnus de dbi services dans lesquels les participants apprendront à gérer l’outil informatique des administrateurs de …

The press, be it the general daily newspaper or the computer magazines, is currently informing the public about an upcoming leap second, which will be taken in the night from June 30 to July 1 at 00:00:00 UTC. While we Europeans will enjoy our well-deserved sleep then, this will be at 5 PM (17:00) local time on June 30 for Califormia people, and during the morning of July 1 for people in China, Japan, Korea, or Australia. (Other countries not mentioned for the sake of brevity.) This is different from last time, when the leap second was taken in the night from Saturday to Sunday (2012-July-1 00:00:00 UTC), so it was a weekend everywhere on the globe.

We have got several requests from our customers about this upcoming leap second, whether they need to take any special precautions or whether they "are safe". Well, obviously nobody is "safe" from the leap second in the sense that it would circumvent them, everybody will encounter it on their …

Applications often become impacted by MySQL performance. Optimization is the obvious solution but where to start? Join me on July 2 at 11 a.m. Pacific and I’ll show you how to optimize MySQL in a practical way – spending time on what gives you the best return. Many of you have heard me talk on this topic before and this updated presentation will get you up to speed on the latest areas to consider when improving MySQL performance.

I’ll be pointing out the most important things you need to get right for each of the following:

• Hardware
• MySQL Configuration
• Schema and Queries
• Application Architecture

I’ll also share some tools and techniques to focus on the queries most important for your application. At the end of this webinar, aptly titled “ …

The MySQL 5.7.6 release notes describe a change to the binary log group commit algorithm that can improve the performance of write intensive applications when the binary log is enabled (noted with Bug #19424075).  This change is probably inspired by the experiment reported in MySQL bug #73202.

There is a long history of tweaking the binary log group commit algorithm and the InnoDB storage engine to scale performance.  Mark Callaghan describes the work done on this problem at Facebook. …

In the MySQL team, we have been refactoring the SQL parser to be more maintainable. Gleb Shchepa lists the goals of this project in more details on the MySQL Server Team blog.

As part of this, we have identified the feature PROCEDURE ANALYSE as something that we would like to deprecate. For added context, here is a demonstration:

mysql> SELECT * FROM City procedure analyse()\G
*************************** 1. row ***************************
             Field_name: world.city.ID
              Min_value: 1
              Max_value: 4079
             Min_length: 1
             Max_length: 4
       Empties_or_zeros: 0
                  Nulls: 0
Avg_value_or_avg_length: 2040.0000 …

MySQL Cluster: El ‘qué’ y el ‘cómo’.

Para aquellos que encuentran mucho sobre MySQL en Inglés pero poco en Español: mi pequeña aportación.
En el enlace tenéis información sobre qué es MySQL Cluster y cómo funciona. Incluso con ejemplos técnicos para romper las barreras y ayudar a simplificarlo (espero).

¡A disfrutar!

While testing installation steps with MySQL 5.7.7-rc, surely you will find much more improvements, changes, deprecated functionality and etc.

The interesting one is activating VALIDATE PASSWORD PLUGIN via mysql_secure_installation script. Which we use by mean “securing” MySQL installations.

I will write a separate topic about MySQL 5.7.7-rc installation steps from source, with related BUG reports.

So after first run:

[root@centos7_vm mysql]# bin/mysql_secure_installation --socket=/opt/mysql/datadir/mysqld-new.sock
Securing the MySQL server deployment.
Connecting to MySQL server using password in '/root/.mysql_secret'

If you notice, now script trying to connect to MySQL using a temporary password which is generated for root@localhost and logged into hidden .mysql_secret file.

VALIDATE PASSWORD PLUGIN can be used to test passwords
and improve security. It checks the strength of …

If you are using Galera Cluster in multi-master mode, you will most likely run into transaction conflicts if two clients attempt to modify the same row at the same time. Such conflicts are reported a deadlock errors to the application.

Legacy applications are frequently unable to handle transaction conflicts properly and may not provide sufficient information to debug the source of the problem.

If the wsrep_log_conflicts option is set, Galera can output all the information about transaction conflicts that is available to it to the error log. As it is a dynamic option, you can enable it while the server is running, collect some entries for examination, and disable it to avoid filling up the log.

Decoding the Output

The output from wsrep_log_conflicts may look a bit intimidating at first, but in fact contains a lot of information that can be used to pin-point the offending application, module or SQL operation. The …