May 24, 2013

Disconnecting a replication slave is easier with MySQL 5.5+ (RESET SLAVE vs. RESET SLAVE ALL)

It’s not uncommon to promote a server from slave to master. One of the key things to protect your data integrity is to make sure that the promoted slave is permanently disconnected from its old master. If not, it may get writes from the old master, which can cause all kinds of data corruption. MySQL [...]

Debugging MySQL SSL problems

This is not necessarily going to be a comprehensive post, but I learned somethings about MySQL SSL today that I thought would be worth sharing. I was setting up a PRM install for a customer and one of the requirements was SSL replication.  In this particular case, I had setup PRM first, and then was [...]

Infinite Replication Loop

Last week I helped 2 different customers with infinite replication loops. I decided to write a blog post about these infinite loop of binary log statements in MySQL Replication. To explain what they are, how to identify them… and how to fix them.

Shard-Query EC2 images available

Infobright and InnoDB AMI images are now available There are now demonstration AMI images for Shard-Query. Each image comes pre-loaded with the data used in the previous Shard-Query blog post. The data in the each image is split into 20 “shards”. This blog post will refer to an EC2 instances as a node from here [...]

What’s up with HandlerSocket?

I’ve presented at two different venues about HandlerSocket recently and the number one question that always arises is: Why hasn’t HandlerSocket become more popular than it is? Considering how fast and awesome HandlerSocket is, it’s not seeing as rapid adoption as some might expect. I theorize that there are five reasons for this:

Using Flexviews – part two, change data capture

In my previous post I introduced materialized view concepts. This post begins with an introduction to change data capture technology and describes some of the ways in which it can be leveraged for your benefit. This is followed by a description of FlexCDC, the change data capture tool included with Flexviews. It continues with an [...]

How is join_buffer_size allocated?

When examining MySQL configuration, we quite often want to know how various buffer sizes are used. This matters because some buffers (sort_buffer_size for example) are allocated to their full size immediately as soon as they are needed, but others are effectively a “max size” and the corresponding buffers are allocated only as big as needed [...]

Why you should ignore MySQL’s key cache hit ratio

I have not caused a fist fight in a while, so it’s time to take off the gloves. I claim that somewhere around of 99% of advice about tuning MySQL’s key cache hit ratio is wrong, even when you hear it from experts. There are two major problems with the key buffer hit ratio, and [...]

Updated msl (microslow) patch, installation walk-through!

For a couple of months there have been no updates to our msl patch, however recently I managed some time to change this. The functionality was extended a little bit and what’s even more important the patch is available for all the recent MySQL releases. To remind anyone who has not yet come across this [...]

Heikki Tuuri answers to Innodb questions, Part II

I now got answers to the second portions of the questions you asked Heikki. If you have not seen the first part it can be found here. Same as during last time I will provide my comments for some of the answers under PZ and will use HT for original Heikkis answer. Q26: You also [...]