April 25, 2014

Ultimate MySQL variable and status reference list

I am constantly referring to the amazing MySQL manual, especially the option and variable reference table. But just as frequently, I want to look up blog posts on variables, or look for content in the Percona documentation or forums. So I present to you what is now my newest Firefox toolbar bookmark: an option and […]

The story of one MySQL Upgrade

I recently worked on upgrading MySQL from one of very early MySQL 5.0 versions to Percona Server 5.1. This was a classical upgrade scenario which can cause surprises. Master and few slaves need to be upgraded. It is a shared database used by tons of applications written by many people over more than 5 years […]

mysql_upgrade and Innodb Tables

Upgrading from MySQL 5.0 to MySQL 5.1 or Percona Server 5.1 you may run into issues with mysql_upgrade – it will identify some tables to be upgraded and will attempt to run REPAIR TABLE for them. This will fail with “The storage engine for the table doesn’t support repair” error message. This seems to confuse […]

Upgrading MySQL

Upgrading MySQL Server is a very interesting task as you can approach it with so much different “depth”. For some this is 15 minutes job for others it is many month projects. Why is that ? Performing MySQL upgrade two things should normally worry you. It is Regressions – functionality regressions when what you’ve been […]

7 Reasons why MySQL Quality will never be the same

I had a call with Monty the other day and I told him why I think MySQL Server Quality will never be the same again. I’ve been thinking a bit more about it and here is the extended list. In particular I think MySQL Server will never be able to reach its original quality guidelines […]

When to use Hardware upgrade instead of Software Optimization

One typical question which frequently pops up is whenever it is better to use hardware upgrade or optimize software more. I already wrote about it, for example here. Today I’ll look at the same topic from the consultants view. When consultant should suggest hardware upgrade and when it is not in a simple checklist form.

How Percona does a MySQL Performance Audit

Our customers or prospective customers often ask us how we do a performance audit (it’s our most popular service). I thought I should write a blog post that will both answer their question, so I can just reply “read all about it at this URL” and share our methodology with readers a little bit. This […]

MySQL 4 to MySQL 5 Upgrade performance regressions

This week I already had two serious performance regression cases when upgrading from MySQL 4.0 and 4.1 to MySQL 5.0. By serious I mean several times performance difference not just 5-10% you often see for simple queries due to generally fatter code. The problem in both cases was MySQL 5.0 broken group commit bug. First […]

MySQL Installation and upgrade scripts.

I generally find MySQL Sever sufficiently tested, meaning at least minor version upgrades rarely cause the problems. Of course it is not perfect and I remember number of big issues when some releases could not be used due to behavior changes in them and when something had to be rolled back in the next release. […]

Heartbleed: Separating FAQ From FUD

If you’ve been following this blog (my colleague, David Busby, posted about it yesterday) or any tech news outlet in the past few days, you’ve probably seen some mention of the “Heartbleed” vulnerability in certain versions of the OpenSSL library. So what is ‘Heartbleed’, really? In short, Heartbleed is an information-leak issue. An attacker can […]