Shinguz's blog

Recently a customer has shown up with some deadlocks occurring frequently. They were of the following type (I have shortened the output a bit):

There is a product out in the wild which is called SchoonerSQL
[ 1
] from an American company called Schooner Information Technology
[ 2
]. They claim to have top-performance
[ 3
] and high-availability features with up 99.999% availability
[ 1
].
The technology seems to be based on InnoDB, SSD and some kind of replication with failover mechanism.

Its a known problem that changing the Storage Engine from MyISAM to InnoDB can cause some problems
[ 1
] if you have queries of this type:

Also this year we will have a special track for MySQL, Galera, Percona und MariaDB at the FrOSCon in St. Augustin in Germany. The conference is scheduled for August 25 and 26 2012.

Table of Contents

• Building the Galera Load Balancer
• Starting the Galera Load Balancer
• Querying the Galera Load Balancer
• Draining nodes with Galera Load Balancer
• Removing nodes from and adding nodes to Galera Load Balancer

When you install a Galera Cluster for MySQL for High Availability (HA) it is not enough to install the Database Cluster to achieve this goal. You also have to make the application aware of this HA functionality. This is typically done with some kind of load balancing mechanism between the database and the application.

FreeBSD 9 seems to have some troubles with MySQL 5.5.20. A customer has moved from MySQL 5.0 on Linux to MySQL 5.5 on FreeBSD 9. He experienced a lot of periodic slow downs on the new, much stronger, system which he has not seen on the old Linux box.

Because we are a bit short off disk space on one of our servers I had the idea to try out the MySQL feature Data Compression for InnoDB. This feature is useful if you have tables with VARCHAR, BLOB or TEXT attributes.

Many of you may monitor their databases for different purposes. Beside alerting it is often good to also make some graphs from MySQL performance counters to see what is actually happening on your database.

In my set-ups I have different MySQL versions (MySQL 5.0, 5.1, 5.5 and 5.6, Percona Server 13.1 and 24.0, MariaDB 5.2.10, 5.3.3, Galera 1.0, 1.1 and 2.0) running in parallel at the same time.

Recently I found in a forum the following request for help:

A few days ago Codership announced their new version Galera v1.1 - synchronous Replication Cluster for MySQL. Before we look at the new feature of Rolling Online Schema Upgrade (OSU) we have a look at how to upgrade to the new Galera release.

Introduction

Galera is a synchronous Multi-Master Replication for MySQL. It is therefore in competition with several other MySQL architectures:

Introduction

Recently a customer claimed that his queries were slow some times and sometimes they were fast.

Introduction

MySQL/Galera synchronous Multi-Master Replication consists of 2 parts:

• The wsrep patches for MySQL (codership-mysql) and
• the Galera Replication Plugin (galera).

If you do not want to download the prepared binaries you can build it on you own.
First you have to download the native MySQL sources, then patch it with the Galera wsrep patches and compile it. In a second step you have to build the Galera Plugin.

Summary: In this article we have a short look at a simple MySQL example program written in Vala.

Our Advanced MySQL Developer Workshop is over now and IMHO it was quite a success.
During the workshop it is planned to have some exercises. If you are curious and if you want to test or train your MySQL skills, find the exercises here: Advanced MySQL Developer Workshop Exercises.

Abstract: In this article we provide a little JMeter WebShop Example Benchmark for MySQL.

Abstract: In this article we have a look at the compression options of common zipping tools and its impact on the size of the compressed files and the compression time. Further we look at the new parallel zip tools which make use of several cores.

Abstract: In this article we discuss how big is the performance impact of MySQL TRIGGERs compared to application side logging (with INSERT) into a MySQL table.