Problem With the release of MySQL 5.1, many DBAs are going to be scheduling downtime to upgrade their MySQL Server. As with all upgrades between major version numbers, it requires one of two upgrade paths: Dump/reload: The safest method of upgrading, but it takes out your server for quite some time, especially if you have a large data set.mysql_upgrade: A much faster method, but it can still be

Just a quick introduction to begin with.

I joined Sun Microsystems in Feb 2009 to look after the product management for MySQL Cluster and MySQL replication.

I started my career with Nortel (technically BNR which was the R&D arm of Northern Telecom but everything later got merged and rebranded as Nortel). I was responsible for writing the original proprietary, in-memory database for Nortel’s HLR product. Later on, we used a number of 3rd party databases for the HLR (provisioning rather than real-time) and then HSS - starting with Oracle for the HLR and then SOLID but then settling on MySQL Cluster as the scaleable real-time database for the HSS.

When I left Nortel (via an IBM rebadging) I moved to Sun, hoping to use my experience as a MySQL Cluster customer to help the team build upon their strong product.

So far, so good - I’ve been really impressed both with the MySQL team and with how well the product is …

It's good to get out of the office and meet people. This year I'll be doing several presentations at the 2009 MySQL Conference and adjacent Percona Performance Conference in Santa Clara. These include among others a talk on Tungsten Replicator on Thursday April 23 at 10:50.

In case you don't read this blog regularly, Tungsten Replicator provides advanced open source replication for MySQL. The term "advanced" is not an exaggeration. I'll be covering how to solve practical problems including the following:

• How to install and configure Tungsten Replicator in 5 …

This time I'll write about a nice featured we now have on the MySQL Proxy.

Parsing master.info
The master.info is a file that the MySQL server creates when you are running a slave server, you can read the manual for more details.
And now you can use the MySQL Proxy to read that file and parse the data from it.

Background
It all started when Jan emailed the proxy discuss mailing with the Changelog from 0.6.1 to 0.7.0. The part that got my attention was:
"...
Core
[skip]
* added parser for master.info files"
... "
As I was working on a Lua script that did some simulation, I …

In December 2007 Werner Vogels posted a blog article entitled Eventual Consistency, since updated with a new article entitled Eventually Consistent - Revisited. In a nutshell it described how to scale databases horizontally across nodes by systematically trading off availability, strict data consistency, and partition resilience as defined by the CAP theorem. According to CAP, you can only have two of three of these properties at any one time. The route to highly available and performant databases, according to Vogels, is eventual consistency in which distributed database contents at some point converge to a single value but at any given time may be …

Sometimes you just have to laugh at the crazy things that can kill a good evening. I had this brilliant idea to change our replication setup on one of our Master-Master replication server setups this week. I got sick of having to restart MySQL every time we wanted to add a new database and have it included in the list of replicated databases - we were using replicate-do-db in our configs.So it

The reference manual explains it in detail.
There are two things that you must remember, if you are …

Suppose you have a MySQL master-slave replication setup. It is very straightforward, nothing exotic at all. Imagine that it is the simplest possible setup. Everything is fine, there is nothing wrong or misconfigured with either server.

Now you add another slave, and replication on your existing slave fails. You did not change anything on your existing slave or master. How did this happen?

I was setting up a slave manually for a quick-and-dirty experiment, when I found this one:

mysql  %gt; slave start;
ERROR 1200 (HY000): The server is not configured as slave; fix in config file or with CHANGE MASTER TO

Hmm... I did the CHANGE MASTER TO already, but just for the sake of it, let's do it again.

mysql %gt; change master to master_host='127.0.0.1', master_port=22346, 
master_user='msandbox', master_password='msandbox', 
master_log_file='mysql-bin.000002', master_log_pos=106;
Query OK, 0 rows affected (0.00 sec)

mysql  %gt; slave start;
ERROR 1200 (HY000): The server is not configured as slave; fix in config file or with CHANGE MASTER TO

Again! Why is it asking to execute CHANGE MASTER TO, which has been accepted right now?

Then it came to me. Because I did a manual configuration, and I …

Problem

With the release of MySQL 5.1, many DBAs are going to be scheduling downtime to upgrade their MySQL Server. As with all upgrades between major version numbers, it requires one of two upgrade paths:

• Dump/reload: The safest method of upgrading, but it takes out your server for quite some time, especially if you have a large data set.
• mysql_upgrade: A much faster method, but it can still be slow for very large data sets.

I’m here to present a third option. It requires minimal application downtime, and is reasonably simple to prepare for and perform.

Preparation

First of all, you’re going to need a second server (which I’ll refer to as S2). It will act as a ’stand-in’, while the main server (which I’ll refer to as S1) is upgraded. Once S2 is ready to go, you can begin the preparation:

• If you haven’t already, enable …