I'm not the only one to have noticed this, but I spent a sufficient amount of time banging my head against a wall finding this out that I thought it important to make more people aware of this.

While trying to validate new database hardware we were seeing some serious performance issues in production.  Most MySQL benchmarks using sysbench or pt-playback couldn't reproduce it, but a simple sysbench 16 threaded filio test on the mysql partition showed about 1/3 the throughput we would expect.   The fact that much of the hardware was new as well as the OS we were using made tracking down the cause difficult (changing from CentOS 5.5 to Scientific Linux 6.)

Finally some of our ops people working on different systems started noticing similar issues, and they uncovered the XFS issue.  Sure enough -- when took existing hardware, upgraded to SL6 and ran the same sysbench filio test we immediately saw a …

As you may expect from open source world thingy, almost every Linux distribution has developed it’s own way to manage our favourite RDBMS service. Yet none is perfect, or even some of them seems to not work in real server scenario1.

In this post I’m trying to compare and point out most annoying aspects of initialization scripts that I had to face in production.

In ‘old days’ probably all Linux distributions used to start and stop services using so called init scripts usually written in Unix shell (sh or Bash). But situation is not so simple these days anymore.

Folks started to think about improving things, like making system initialization faster by parallelization of starting services. So Upstart was developed in …

My colleagues and I are looking for extra talent – is that you?

What we do:help clients prevent problems (rather than being the fire department), we work on a subscription basis although we also do some ad-hoc consulting, and training. Apart from MySQL/MariaDB query and DBA work, we do quite a bit of system administration. Mainly Red Hat and Debian based distros, and expect to see replication and the MySQL-MMM multi-master system. You’d work from home, whereever it might be, so you will need to be self-motivating (but we do keep in touch online).

What we’re not: a full-time employer. With us, you make a life rather than a living. Everybody is contracted part-time. You can make enough to live comfortably, but that has nothing to do with hours. If you’re stressed about not filling all hours in your week with work-work-work, we’re not the company for you… there’s more to life than …

A blog post on how to deploy a sample JBoss application on OpenShift Flex - using a highly available, scalable backend that leverages MySQL Cluster

The Severalnines team has been busy during the summer months and as result, we have included OpenShift Flex support to our Severalnines Configurator (amongst other things). OpenShift, a Platform-as-a-Service operated by Red Hat, allows developers to develop and manage applications in the cloud. It is now possible to configure a clustered MySQL database for cloud services running on OpenShift. This brings high-availability and scalability at both the application and database layers.

As a guest contributor on …

Until now, MariaDB 5.2 was lacking a yum repository for easy installs and upgrades. It is now available, thanks to OurDelta.

Just follow our very simple installation instructions.

This is one of a few MySQL High Availability strategies.  I have used this for years and found it work great.  If you don’t know about DRBD and MySQL you should read Peter’s comments.

These are step by step instructions for Redhat 5 or CentOS.

If you need more details please refer to:
http://www.drbd.org/users-guide/

Configuring MySQL for DRBD
http://dev.mysql.com/doc/refman/5.1/en/ha-drbd-install-mysql.html

Getting started:

The OS in this example is CentOS 5.5.  I added a new disk (/dev/sde) to the four disk RAID-5 and RAID-1 I was already using.   I’m only creating an 8 …

If you’ve been reading up on the various NoSQL offerings and have wanted to try out one but don’t know how to get started, this is one of the easiest ways. I chose MongoDB for this example because I’m going to start using it for a project that needs features that MySQL isn’t as fast at: namely denormalized data with billions of rows. MongoDB has plenty of drivers for other scripting and high-level languages but I’ll focus on the PHP driver today. If there is interest I can do a write up on Python usage later. This example is limited to CentOS, Fedora, and Redhat 5 servers that use the yum package management system. For more information you can reference their download page: http://www.mongodb.org/display/DOCS/Downloads

First install the prerequisites:

• sudo yum install gcc php php-pear

Then install the mogo php extension via …

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Is MariaDB really a drop in replacement for MySQL?   I’m running CentOS 5.4.  What happens if…

1. Use “mysqldump –all-databases > FullBackup.sql” to make a full backup. (Better safe then sorry)
2. Go to http://askmonty.org/wiki/MariaDB:Download and download the CentOS 5 packages.
3. Stop msql “service mysqld stop”
4. Pull MySQL out by the roots with “rpm -e mysql-server mysql –nodeps”
5. Install Maria with “rpm -i Maria-*”

And the install start mysql up again.  Wow.  That’s “Drop in”.

If your reading this, you’re seeing it works.

Building and installing the Ruby mysql gem on freshly-installed Red Hat based systems sometimes produces the frustratingly ambiguous error below:

# gem install mysql
/usr/bin/ruby extconf.rb
checking for mysql_ssl_set()... no
checking for rb_str_set_len()... no
checking for rb_thread_start_timer()... no
checking for mysql.h... no
checking for mysql/mysql.h... no
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

Searching the web for info on this error yields two basic solutions:

1. Install the mysql-devel package (this provides the mysql.h file in /usr/include/mysql/).
2. Run gem install mysql -- …

I have a problem with an easy way to install MySQL via rpm without resorting to specifying the exact point release of MySQL. Presently my local yum repository has versions of 5.0, 5.1,5.4 and 5.5.

If I want to install MySQL Sever, I can just run:

$ sudo yum install -y MySQL-server
Setting up Install Process
Package MySQL-server-community-5.5.0-1.rhel5.x86_64 already installed and latest version
Nothing to do

The issue here is the most current version is installed. If I want to install the most current version of 5.1 for example, I have found no way to specify MySQL-server-5.1, or MySQL-server-community-5.1, I have to specify the point release MySQL-server-community-5.1.40

I suspect there is some internal aliasing that may be possible within rpm’s to support this. I’m seeking help from any rpm experts and would appreciate any feedback.

My current products include:

$ sudo yum list …