Co-Author: Rafael Alvarez

When you look up the word idempotence in wikipedia you get the following definition: Idempotence is the property of certain operations in mathematics and computer science whereby they can be applied multiple times without changing the result beyond the initial application.

When I think of idempotence in the sense of how IT operations work, the very first thing that comes to mind is Ansible. In Ansible you have a yml file that represents a state you want the target host to be in. For example, I can use the yum module to ensure that MySQL is installed on my RHEL virtual machine. When the playbook is run, it checks if MySQL is installed. If not, it will install it. It is installed, then it will ignore that …

Parallel replication has been around for a few years now but is still not that commonly used. I had a customer where the master had a very large write workload. The slave could not keep up so I recommended to use parallel slave threads. But how can I measure if it really helps and is working?

At my customer the

slave_parallel_workers

  was 0. But how big should I increase it, maybe to 1? Maybe to 10? There is a blog post about how can we see how many threads are actually used, which is a great help.

We changed the following variables on the slave:

slave_parallel_type = LOGICAL_CLOCK;
slave_parallel_workers = 40;
slave_preserve_commit_order = ON;

40 threads sounds a lot, right? Of course, this is workload specific: if the transactions are independent it might be …

MySQL InnoDB Cluster Setup and Configuration

Reference :
https://dev.mysql.com/doc/refman/8.0/en/mysql-innodb-cluster-production-deployment.html

Pr-requisite  Assumption :
    MySQL Server 8.0.12+ installation : /usr/local/mysql
    MySQL Shell installation : /usr/local/shell
    MySQL Router Installation : /usr/local/router
    Hostname and IP must be resolvable. 
        Make sure the /etc/hosts valid to have the IP and Hostname entries correctly with ALL MySQL Server machines.

The Video [ https://youtu.be/_jR_bJGTf-o ] provides the full steps showing the Demonstration of
1. Setting up of 3 x MySQL Servers on 1 VM
    a.  Configuration my1.cnf, my2.cnf and …

We would like to announce the shows & conferences where you can find MySQL Community Team or MySQL representatives at. Please be aware that the list below could be subject of change.

October 2018

• GITEX, Dubai, United Arab Emirates, October 14-18, 2018

  • Same as last year Oracle & MySQL are part of GITEX converence. There is an Oracle booth (Stand A5-01, Hall 5) as well as MySQL one (POD2, Hall 5) where you can find us. 
• ZendCon, Las Vegas, US, October 15-17, 2018
  • We are Exhibitor sponsor same as last year, however newly this year we are going to have a new very cool booth design! Come to check and talk to us there!
  • Also if you are around, do not miss the sessions by …

Your database cluster contains your most business-critical data and therefore proper performance under load is critical to business health. If response time is slow, customers (and staff) get frustrated and the business suffers a slow-down.

If the database layer is unable to keep up with demand, all applications can and will suffer slow performance as a result.

To prevent this situation, use load tests to determine the throughput as objectively as possible.

In the sample load.pl script below, increase load by increasing the thread quantity.

You could also run this on a database with data in it without polluting the existing data since new test databases are created to match each node’s hostname for uniqueness.

Note: The examples in this blog post assume that a Connector is …

Error Message: ERROR 1396 (HY000): Operation CREATE USER failed for 'admin'@'%'
Generic Error Message:Operation %s failed for %s
Error Scenario:Operation CREATE USER failed
Operation DROP USER failed

Reason:The reason for this error is, you are trying to do some user operation but the user does not exist on the MySQL system. Also, for drop user, the user details are stored somewhere in the system, even though, you have already dropped the user from MySQL server.
Resolution:Revoke all access granted to the user, drop the user, and run FLUSH PRIVILEGE command to remove the caches. Now create/drop/alter the user, it will work.
REVOKE ALL ON *.* FROM 'user'@'host';DROP USER 'user'@'host';FLUSH PRIVILEGES;
Grant Tables:The following tables will help you in identifying the user related informations (as of MySQL 5.7):

mysql.user: User accounts, global privileges, and other non-privilege …

For Percona Live Europe this year, I got accepted a workshop on query optimization and a 50-minute talk covering TLS for MySQL at Large Scale, talking about our experiences at the Wikimedia Foundation.

Workshop

The 3-hour workshop on Monday, titled Query Optimization with MySQL 8.0 and MariaDB 10.3: The Basics is a beginners’ tutorial–though dense in content. It’s for people who are more familiar with database storage systems other than InnoDB for MySQL, MariaDB or Percona Server. Or who, already familiar with …

We will have a kiosk at Moscone Center, south exhibition hall, Oracle’s Data Management area number 123, close to high availability area and exits 16 and 18. Our kiosk number is DBA-P1.

Our CEO and Co-Founder Seppo Jaakola will host a presentation highlighting the main features of our upcoming Galera Cluster 4.0. The presentation will take place Monday, Oct 22, 1:00 p.m. – 1:20 p.m at the Exchange @ Moscone South – Theater 2. Seats are limited!

Come and meet us! Let’s discuss your MySQL high availability plan or your Galera Cluster deployment. If you want to set up a meeting with us please email to ínfo@galeracluster.com for a meeting request.

You all heard about that today AWS announced that RDS is started to support GTID Transactions. I’m a great fan of RDS but not for GTID. Since RDS has better settings and configurations to perform well. Many of you people read about the AWS What’s new page regarding GTID. But here we are going to talk about the actual benefits and drawbacks.

RDS supports GTID on MySQL 5.7.23 or later. But AWS released this version on Oct10 (two days before). So, for now, this is the only version which supports GTID.

NOTE: GTID supports only for RDS, its not available for Aurora. It may support in future)
Update : 27 March 2019: Aurora MySQL 5.7 supports GTID. Find the relavent link below.

Before configuring the GTID, lets have a look at what is GTID?

• GTID stands for Global Transaction Identifier.
• It’ll generate a …

The 2018 MySQL Community Reception is October 23rd in a new venue at Samovar Tea, 730 Howard Street in San Francisco at 7:00 PM.   Right in the heart of the Moscone Center activities for Oracle OpenWorld and Oracle Code one activities.

The MySQL Community Reception is not part of Oracle OpenWorld or Oracle Code One (you do not need a badge for either event) but you do need to RSVP.  Food, drinks, and a really amazing group of attendees!   And there will be more than tea to drink.

Plus we have a few new surprises this year!