"Split Brain" is the term commonly used for a cluster whose nodes have different contents, rather than identical as they should have. Typically, a "split brain" situation is the DBA's nightmare, and the Galera software is designed to avoid it. Galera is very successful in that avoidance, and it needs some special steps by the DBA to achieve "split brain". Here is how to do it - or, for most DBAs, what to avoid doing to not get a split-brain cluster.

Galera's Design

First, let's remember how Galera is operating:

• The Galera software ensures that all nodes participating in a cluster will start from identical contents, by doing a "snapshot state transfer" (SST) of all current data to a newly joining node.
• When the cluster is running, Galera transfers all changes (transactions) to all cluster nodes and applies them (or rolls back and ignores, in the case of a conflict).
• If some connections get …

Requires ClusterControl 1.2.11 or later. Applies to MySQL based clusters.

During the life cycle of Database installation it is common that new user accounts are created. It is a good practice to once in a while verify that the security is up to standards. That is, there should at least not be any accounts with global access rights, or accounts without password.

Using ClusterControl, you can at any time perform a security audit.

In the User Interface go to Manage > Developer Studio. Expand the folders so that you see s9s/mysql/programs. Click on security_audit.js and then press Compile and Run.

If there are problems you will clearly see it in the messages section:

…

One of the common questions we get during sales demos is “does VividCortex give advice on my database’s configuration?” The assumption is that since our product sees lots of information about the database, operating system, and current configuration, it can “optimize” the database configuration. Or, at least, point out really obviously bad things? Surely that is not too hard to do?

VividCortex doesn’t do that, and there are good reasons why. By way of explanation I’d like to tell a few war stories. Warning: you’re probably going to vow never to look at auto-generated tuning advice again.

Get Down Off The Ledge

At one point, a significant chunk of my career and earnings consisted of undoing the damage caused by configuration advisors. It was often very hard to convince people to reverse the changes the configuration advisors had urged them to make. It’s a psychological problem, not a technical one.

With the new GA release 6.3.5 we finally also managed to bring MySQL Workbench to Github. This is something we planned for quite some time and now the repository is part of the MySQL group at Github. Go Workbench…

FOSDEM 2016 edition will be held January 30 and 31 in Brussels like every year since 2000.

The MySQL & Friends Devroom is back on Saturday from 9.00AM.

What is FOSDEM? It stands for the “Free and Open Source Software Developers’ European Meeting.” It’s a free event that offers open-source communities a place to meet, share ideas and collaborate.

CfP is open until December 1st!

Don’t forget to submit your sessions (submit here, don’t forget to select MySQL track) before December and see you soon in Brussels to discover amazing stuff related to MySQL and have some beers with …

I’m pleased to announce: MySQL Connector/J 5.1.37 Maintenance Release is now available.

MySQL Connector/J can be downloaded from the official distribution channels MySQL Downloads and The Central repository. Commercial license version is available for download at My Oracle Support.

As always, we recommend that you check the “CHANGES” file in the
download archive and/or the release notes to be aware of changes in behavior that might affect your application.

MySQL Connector/J 5.1.37 includes several bug fixes and other improvements. I’d like to …

GreenSQL Securing MySQL Database Application

After identifying the need for a more thorough and stringent database security solution, GreenSQL took as its mission the creation of the most comprehensive, holistic, and robust application for database security and protection. With its roots in the open-source community, GreenSQL developed the first MySQL Database application Database Firewall as open-source software. It took the vast knowledge that it gained from the open-source community and poured it into the capabilities of the GreenSQL.

The post GreenSQL Securing MySQL Database …

Percona is glad to announce the release of Percona XtraBackup 2.3.2 GA on October 22nd, 2015. Downloads are available from our download site or Percona Software Repositories.

Percona XtraBackup enables MySQL backups without blocking user queries, making it ideal for companies with large data sets and mission-critical applications that cannot tolerate long periods of downtime. Offered free as an open source solution, Percona XtraBackup drives down backup costs while providing unique features for MySQL backups.

…

Percona is glad to announce the release of Percona XtraBackup 2.2.13 on October 22nd, 2015. Downloads are available from our download site or Percona Software Repositories.

Percona XtraBackup enables MySQL backups without blocking user queries, making it ideal for companies with large data sets and mission-critical applications that cannot tolerate long periods of downtime. Offered free as an open source solution, Percona XtraBackup drives down backup costs while providing unique features for MySQL …

Dear MySQL users,

MySQL Connector/Net 6.7.9, 6.8.7, and 6.9.8 are maintenance releases for the series of the .NET driver for MySQL. They can be used for production environments.

They are appropriate for use with MySQL server versions 5.5-5.7.

• The GB18030 Chinese character set is now supported, a character set that was added in MySQL 5.7.4.
• The JSON type is now supported, a type that was added in MySQL 5.7.8.
• Generated columns (GENERATION_EXPRESSION) are now supported, a feature added in MySQL 5.7.6.

An additional entry added for 6.8.7:

• A connection string that included Chinese characters for a database or uid property would emit the following exception;
  “MySqlException: Unknown database ‘???'”. To solve this, the handshake process was hanged to use bytes instead of encoded strings.

The …