November 26, 2014

MySQL upgrade best practices

MySQL upgrades are necessary tasks and we field a variety of questions here at Percona Support regarding MySQL upgrade best practices. This post highlights recommended ways to upgrade MySQL in different scenarios. Why are MySQL upgrades needed? The reasons are many and include: Access to new features, performance benefits, bug fixes…. However, MySQL upgrades can […]

Bug#12704861

As Mark pointed out, there isn’t a lot of detail in the release notes about what could potentially be a very serious problem that is fixed in MySQL 5.1.60. I’ll repeat here the full documentation from the release notes: “InnoDB Storage Engine: Data from BLOB columns could be lost if the server crashed at a precise […]

Data Corruption, DRBD and story of bug

Working with customer, I faced pretty nasty bug, which is actually not rare situation , but in this particular there are some lessons I would like to share. The case is pretty much described in bug 55981, or in pastebin. Everything below is related to InnoDB-plugin/XtraDB, but not to regular InnoDB ( i.e in MySQL […]

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 […]

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 […]

MySQL 5.1 went to GA. Was it a good move ?

MySQL 5.1 release as “GA” seems to be the most controversial to date. It had very negative response from Monty, original MySQL Founder and controversial responses in community including another beating by Kevin Burton. There is also very interesting reading on MySQL 5.1 open bugs So how do I take it and where do I […]

MySQL 5.1 is to reach GA state – all to arms !

MySQL 5.1 was in RC stage for around 10 months now finally planned to be released as GA soon. As Monty Says MySQL 5.1.26 will be renamed as GA if no serious bugs are discovered. Lets help MySQL to ensure GA release will be indeed GA quality and support Monty in his call to ensure […]

Making bugs public – good job MySQL

If you have been MySQL User for many years you might remember the times when MySQL had “zero bugs policy”, this is when all known bugs really were fixed before release was made. To be honest at that time bugs were reported via bugs mailing list not via bugs database as they are now so […]

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 […]