I was fortunate to attend an Ops discussion about databases at the OpenStack Summit Atlanta this past May as one of the panelists. The discussion was about deadlock issues OpenStack operators see with Percona XtraDB Cluster (of course this is applicable to any Galera-based solution). I asked to describe what they are seeing, and as it turned out, nova and neutron uses the SELECT … FOR UPDATE SQL construct quite heavily. This is a topic I thought was worth writing about.

Write set replication in a nutshell (with oversimplification)

Any node is writable, and replication happens in write sets. A write …

September 11, 2014 By Severalnines

Thanks to everyone who attended and participated in this week’s webinar on ‘Performance Tuning of HAProxy for Database Load Balancing’. And special thanks to our guest speaker, Baptiste Assmann of HAProxy Technologies. 

If you missed the sessions or would like to watch the webinar again & browse through the slides, they are now available online.

Watch the replay of this webinar to learn about what HAProxy can tell you about your application and database instances. And understand the difference between short-lived connections and persistent connections, and how they affect the performance and availability of your applications. 

Watch the replay Performance Tuning of …

MySQL Central @ OpenWorld is coming up soon. I look forward to present What’s New in MySQL 5.7? on Tuesday, Sep 30, 12:00 PM – 12:45 PM – Moscone South – 252.  Join product manager Mike Frank and myself to discuss the big picture! We will cover:

• InnoDB Performance & Scalability: Over 600 thousand QPS for SQL queries, over 1.1 million QPS for  Memcached API, over 60 thousand connects/ disconnects per second, parallel flushing, bulk data load and more.
• Optimizer: New optimizations,  new architecture for the parser, new architecture for the optimizer, new additions leading to a new cost model designed to handle latest OS and hardware innovations.
• …

September 10, 2014 By Severalnines

If you are automating your infrastructure using Puppet, then this blog is for you. We are glad to announce the availability of a Puppet module for ClusterControl. For those using Chef, we already published Chef cookbooks for Galera Cluster and ClusterControl some time back.  

ClusterControl on Puppet Forge

The ClusterControl module initial release is available on Puppet Forge, installing the module is as easy as:

$ puppet module install severalnines-clustercontrol

If you haven’t change the default module path, this module will be installed under /etc/puppet/modules/clustercontrol on …

There are a lot of tools that generate test data.  Many of them have complex XML scripts or GUI interfaces that let you identify characteristics about the data. For testing query performance and many other applications, however, a simple quick and dirty data generator which can be constructed at the MySQL command line is useful.

First, let’s talk about what kind of data you can easily create with MySQL function calls:

You can generate a decimal number between zero and another number using the MySQL RAND() function like the following query (here between 0 and 10000):

SELECT RAND() * 10000;

Similarly, you can generate a random integer by adding the FLOOR() function:

SELECT FLOOR(RAND() * 10000)

You can generate a random string of 32 characters using MD5():

SELECT MD5(RAND() * 10000)

You can return a random integer between 500 and 1000 with the following:

A common migration path from standalone MySQL/Percona Server to a Percona XtraDB Cluster (PXC) environment involves some measure of time where one node in the new cluster has been configured as a slave of the production master that the cluster is slated to replace. In this way, the new cluster acts as a slave of the production environment – traditional replication takes care of getting the data into the cluster, and then Galera replication handles the intra-cluster traffic. This often works without issue, although there is one case that I’ve encountered recently where special care must be taken to properly configure the stream to ensure that replication does not break. If you use multi-valued inserts with auto-increment columns, then this post is for you.

For purposes of our discussion, assume that we have a basic 3-node PXC cluster that we’ve set up …

MySQL Central @ OpenWorld is only 20 days away! It is therefore time to start planning your conference, and Schedule Builder is a useful tool we recommend to use.

On Monday, September 29, you have the opportunity to attend MySQL tutorials. Each tutorial will last 2 hours and help you acquire in-depth knowledge on a number of MySQL topics. You will be able to choose from:

10:15 am - 12:15 pm

How to Analyze and Tune MySQL Queries for Better Performance
Øystein Grøvlen, Senior Principal Software Engineer, Oracle

Moscone South - 250

…

Are you using or interested in learning more about MySQL? Are you attending Oracle OpenWorld and looking for an opportunity to meet and exchange ideas or experiences with MySQL users?

Join us on Tuesday, September 30, 2014 to celebrate the dynamics and growth of the MySQL community. Whether you are attending MySQL Central @ OpenWorld, a member of local MySQL user groups, a MySQL user in the Bay Area, or simply interested in MySQL technology, you're all invited to Oracle's MySQL Community Reception.

• Mingle with your peers and learn from real-world experiences.
• Talk to MySQL engineers face-to-face and get the first-hand information on the latest product development.

Time: Tuesday, September 30, 2014 @ 7:00 p.m. - 9:00 p.m.

Location: Jillian's at Metreon …

September 9, 2014 By Severalnines

We are excited to announce the availability of YUM/APT repositories for ClusterControl, making new releases of ClusterControl  easily accessible using YUM or APT package managers. The repo is found at http://repo.severalnines.com, with instructions provided on the landing page. Our Cluster Configurators will be using these repositories. As a result, users upgrading from s9s_upgrade_cmon starting from version v.1.2.8 will be configured with the package repository.

ClusterControl requires extra post-installation setup steps, such as generating an API token, configuring cmon/dcps database schema, grant privileges on cmon schema, setting up SSL and so on. We provide a post-installation script for this purpose at [Apache document …

Dear MySQL users,
MySQL Connector/Net 6.9.3 is the first GA release for the 6.9.x series of the .NET driver for MySQL. It can be used for production environments.
It is appropriate for use with MySQL server versions 5.5-5.7.
It is now available in source and binary form from http://dev.mysql.com/downloads/connector/net/#downloadsandmirrorsites (note that not all mirror sites may be up to date at this point-if you can't find this version on some mirror, please try again later or choose another download site.)
Enjoy and thanks for the support!
On behalf of the MySQL Connector/NET and the MySQL/ORACLE RE Team.