When setting up TokuDB, you may encounter error 1126.

I’ve seen 2 recent invocations of it, so I wanted to share them both here in case you run into this issue:

MariaDB [(none)]> install soname 'ha_tokudb';
ERROR 1126 (HY000): Can't open shared library
'/usr/lib/mysql/plugin/ha_tokudb.so' (errno: 2, undefined symbol: bitmap_free)

MariaDB [(none)]> install soname 'ha_tokudb';
ERROR 1126 (HY000): Can't open shared library 'ha_tokudb.so'
(errno: 8, API version for STORAGE ENGINE plugin TokuDB not
supported by this version of the server)

The latter is a bit more descriptive, but the former is fairly cryptic.

Given the latter, as you may have guessed it, if you run into either of these, you have the wrong version of ha_tokudb.so in your plugin directory – that is, it is not the correct version for your MariaDB/MySQL.

In both cases, 10.0.11 was used. In the first case, the ha_tokudb.so was from …

If you want to use TokuDB with MariaDB, MySQL, or Percona Server, you will need to disable support for transparent hugepages in Linux.

Fortunately, this is very easy to check, and to change.

An easy way to check is with:

cat /sys/kernel/mm/transparent_hugepage/enabled

This will return something like:

[always] madvise never

Note the word surrounded by “[]” is what this option is set to. So the above is set to “always”. To disable it, we want it set to “never”.

I’ve found the easiest way to change/set this is to add the below to your /etc/rc.local file (and then reboot your system):

if test -f /sys/kernel/mm/transparent_hugepage/enabled; then
   echo never > /sys/kernel/mm/transparent_hugepage/enabled
fi
if test -f /sys/kernel/mm/transparent_hugepage/defrag; then
   echo …

TokuDB is gaining more and more popularity and many people are finding it very helpful for certain cases.

Using/enabling it in some distributions can be quite a pain, but enabling it in MariaDB is easy as 1-2-…, well, only 1-2, since that’s all there is to it!

1. Ensure you have the correct MariaDB version:

• MariaDB 5.5.36+
• MariaDB 10.0.9+
• Note: Linux 64-bit systems only – specific packages include: Ubuntu, Debian, Fedora, CentOS, Red Hat
• Note: If using the Linux tarball – it must be the version built with glibc 2.14+

2. Run this command:

INSTALL SONAME 'ha_tokudb';

or update my.cnf file with:

[mysqld]
plugin-load=ha_tokudb

There is one requirement from TokuDB, which is to have transparent …

There are several ways to upgrade MySQL. In this post, we will use a combination of shell scripts and the mysqldump application to export our MySQL data, and then re-import it back into the upgraded version of MySQL.

In this example, we will be doing a minor version upgrade. We will be going from 5.6.17 to 5.6.19. This method may not work if you are upgrading from one major release to another – from 5.1 to 5.5, or 5.5 to 5.6. You will want to check each version and review the new features/functions and also what features/functions have been deprecated. We are also assuming that no one will be using the database during the time it takes for us to do the upgrade.

If you want to upgrade from a …

MySQL 5.5.39 was recently released (it is the latest MySQL 5.5, is GA), and is available for download here:

http://downloads.skysql.com/archive/index/p/mysql/v/5.5.39

This release, similar to the last 5.5 release, is mostly uneventful.

There were two “Functionality Added or Changed” and 24 bugs fixed.

The “Functionality Added or Changed” changes are:

• CMake support was updated to handle CMake version 3.
• The timed_mutexes system variable has no effect and is deprecated.

Out of the 24 bugs, most seemed rather minor or obscure, but here are the ones I think are worth noting (crashing, security, wrong results, deadlock):

• InnoDB: Opening a parent table that has thousands of child tables could result in a long semaphore wait condition.
• …

Last week we released Connector/Python v2.0 (alpha); today we publish the source on GitHub. Yes, we are using Git internally and are now able to push it out on each release. Previous versions are still available through LaunchPad.

Here is the full process to get Connector/Python installed in a virtual environment. You’ll need Git installed of course.

shell> git clone https://github.com/oracle/mysql-connector-python.git cpy
shell> virtualenv ENVCPY
shell> source ENVCPY/bin/activate
(ENVCPY)shell> cd cpy
(ENVCPY)shell> python setup.py install
(ENVCPY)shell> python
>>> import mysql.connector
>>> mysql.connector.__version__ …

MySQL plays a critical role in OpenStack. It serves as the host database supporting most components such as Nova, Glance, and Keystone and is the most mature guest database in Trove. Many OpenStack operators use Percona open source software including the MySQL drop-in compatible Percona Server and Galera-based Percona XtraDB Cluster as well as tools such as Percona XtraBackup and Percona Toolkit. We see a need in the community to understand how to improve MySQL performance …

In the first post in a series on MariaDB features we find interesting, we begin with selectively skipping replication of binlog events. This feature is available on MariaDB 5.5 and 10.

By default when using MySQL’s standard replication, all events are logged in the binary log and those binary log events are replicated to all slaves (it’s possible to filter out some schema). But with this feature, it’s also possible to bypass some events to be replicated on the slave(s) even if they are written in the binary log. Having those event in the binary logs is always useful for point-in-time recovery.

Indeed, usually when we need to not replicate an event, we set sql_log_bin = 0 and the event is bypassed: neither …

Percona Server version 5.1.73-14.12

Percona is glad to announce the release of Percona Server 5.1.73-14.12 on July 31st, 2014 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.1.73, including all the bug fixes in it, Percona Server 5.1.73-14.12 is now the current stable release in the 5.1 series. All of Percona‘s software is …

Today, I was reminded of a Jim Starkey quote on the Random Query Generator:

“The Colonoscopy of Database Software”
– Jim Starkey

If your project does not have something that you can adapt that quote to, odds are your testing is inadequate.