In the life of a professional MySQL DBA there comes a moment when issues are no longer trivial enough to be diagnosed using simple repros and built-in diagnostic commands. While trying to understand complex problems, you may be forced (challenged?) to look for answers at the lowest level, by analyzing the server's source code.
If you're a seasoned database engineer who killed several keyboards reporting MySQL bugs, you can stop reading now. If you're just about to begin your journey into the source, you could probably use all the help you can get so keep reading. In this short article I'll describe the MySQL server tracing feature I've been using as an aid during MySQL investigations. When investigating issues at code level, one of the first questions you will ask yourself is "where do I start?". Let's say you're attempting to debug a SHOW CREATE …

Errant transactions are a major issue when using GTID replication. Although this isn’t something new, the drawbacks are more notorious with GTID than with regular replication.

The situation where errant transaction bites you is a common DBA task: Failover. Now that tools like MHA have support for GTID replication (starting from 0.56 version), this protocol is becoming more popular, and so are the issues with errant transactions. Luckily, the fix is as simple as …

Checksum is a standard practice among DBAs to verify the data consistency across replicated nodes. In this post we’re going to review the syncing options for an inconsistent MySQL slave of Galera cluster node.

Here we’re assuming a setup of regular replication to a MySQL instance from one of the Galera cluster nodes.

In the usual MySQL replication setup, standard practice involves the usage of the pt-table-checksum tool to identify the discrepancies and usage of pt-table-sync to bring them in sync. The checksum tool, pt-table-checksum, can run across Galera cluster node to verify the data consistency and confirm if the MySQL slave is consistent with a chosen primary node.

What happens if this Galera cluster’s regular MySQL slave sees data inconsistency on it? Will pt-table-sync work there? The answer to this depends…
pt-table-sync when used with –sync-to-master …

MariaDB CONNECT storage engine handles access to JSON files through standard SQL. It comes with a set of UDFs (user defined functions) to manipulate the JSON format. This JSON content can be stored in a normal text column. This approach can be used to implement dynamic columns. The dynamic column concept was first introduced with ...continue reading "Using JSON as Dynamic Columns with MariaDB"

Certificate for installers and nightly builds

Finally I bought a certificate at certum.eu to sign the HeidiSQL installers and nightly build files. The latest built installer and nightly builds now don't show a warning message in Windows 7, 8 and 10 any longer. Instead, Windows 7 displays the certificate owner in a dialog when executing:

For all Open Source developers - here's my tutorial for obtaining and managing a code signing certificate using signtool.exe.

Markdown syntax support in this forum

After updating most webserver components on heidisql.com I thought I could add Markdown support to the forum. Markdown provides an easy-to-read, …

In the past five posts of the blog series, we covered deployment of clustering/replication (MySQL / Galera, MySQL Replication, MongoDB & PostgreSQL), management & monitoring of your existing databases and clusters, performance monitoring and health, how to make your setup highly available through HAProxy and MaxScale and in the last post, how to prepare …

Here’s a step-by-step guide on how to invert roles for master and slave so you can perform a master server upgrade, and then switch roles back to the original setup.

* While following this guide consider server-A as your original master and server-B as your original slave. We will assume server-B already produces binlogs and that both nodes have log-slave-updates=1 in my.cnf

Check this following link for more details on log-slave-updates: https://dev.mysql.com/doc/refman/5.6/en/replication-options-slave.html#option_mysqld_log-slave-updates

1. Prepare the original Slave to invert roles.

Make sure the slave is …

Sweden’s self-funded database provider powers past 2014 revenues and grows team

Stockholm, Sweden and anywhere else in the world - 01 DECEMBER 2015 - Severalnines, a database automation pioneer which helps businesses deploy and manage open source databases in any environment, closes 2015 on a high with new customer wins and new hires.
 
Momentum highlights:

• Over 100% sales growth achieved early in first half of 2015
• 150+ enterprise customers, 8,000+ community users
• New enterprise accounts wins such as the European Broadcast Union, European Gravitational Observatory, BT Expedite and French national scientific research centre, CNRS
• Hired Gerry Treacy, former MongoDB executive, as Vice President of Sales
• Added support for PostgreSQL to ClusterControl alongside MySQL …

The client library — libmysqlclient — is part of the same source code repository as the server. It comes both as a dynamic link library (.so), also called a shared library, and as a static link library (.a). During the 5.7 development cycle, we’ve made several improvements to the library, which has resulted in a bump from ABI version 18 to version 20.…

The Call for Papers is over !

Thank you to all of you who have submitted a talk for the Fosdem 2016 MySQL & Friends devroom !

We received 40 talks that will be sent to the committee for review. Then as soon as the talks we be rated, we will contact all the submitters to let them know if their talk(s) was approved or not.

Be patient ! ;-)

Thank you again, this will be an awesome event !