Check Out Our Latest Technical Resources for MySQL, MariaDB & MongoDB Clusters

Like every month this year, we have created new content and tools for you; here is a summary of what we’ve published this December. Please do check it out and let us know if you have any comments or feedback.

And thank you for following us in the past 12 months and for your fidelity; we look forward to “seeing” you next year as well and wish you a great start to 2015!

New Live Technical Webinars

Infrastructure automation isn’t easy, but it’s not rocket science either, says Riaan Nolan. Riaan has been in operations for the past decade, and has built over a dozen eCommerce …

Multi master topologies blues

Tungsten Replicator is a powerful replication engine that, in addition to providing the same features as MySQL Replication, can also create several topologies, such as

• all-masters: every master in the deployment is a master, and all nodes are connected point-to-point, so that there is no single point of failure (SPOF).
• fan-in: Several masters can replicate into a single slave;
• star: It’s an all-masters topology, where one node acts as hub which simplifies the deployment at the price of creating a SPOF.

The real weakness of these topologies is that they don’t come together easily. Installation requires several commands, and running them unassisted is a daunting task. Some time ago, we introduced a set of scripts (the Tungsten Cookbook) that allow you to install multi-master topologies with a …

Overview

First off, the important news. Tungsten Replicator 2.1.0 was released today.
You can download it and give it a try right now.

Second, I would say that I am quite surprised at how much we have done in this release. The previous release (2.0.7) was in February, which is just a few months ago, and yet it looks like ages when I see the list of improvements, new features and bug fixes in the Release Notes. I did not realized it until I ran my last batch of checks to test the upgrade from the previous release, which I hadn’t run for quite a long time. It’s …

Switching roles

To get a taste of the power of Tungsten Replicator, we will show how to switch roles. This is a controlled operation (as opposed to fail-over), where we can decide when to switch and which nodes are involved.

In our topology, host1 is the master, and we have three slaves. We can either ask for a switch and let the script select the first available slave, or tell the script which slave should be promoted. The script will show us the steps needed to perform the operation.

IMPORTANT! Please note that this operation is not risk free. Tungsten replicator is a simple replication system, not a complete management tool like Continuent Tungsten. WIth the replicator, you must make sure that the applications have stopped writing to the master before starting the switch, and then you should address the application to the new master when the …

Intro

Tungsten Replicator is an open source tool that does high performance replication across database servers. It was designed to replace MySQL replication, although it also supports replication from and to Oracle and other systems. In this article, we will only cover MySQL replication, both simple and multi-master.

Preparing for installation

To follow the material in this article, you will need a recent build of Tungsten Replicator. You can get the latest ones from http://bit.ly/tr20_builds. In this article, we are using build 2.0.8-167.

Before starting any installation, you should make sure that you have satisfied all the prerequisites. Don't underestimate the list. Any missing …

The blog title says it all: Do we need a MySQL Cookbook? I tend to think so.

This seems to be something that is missing with current MySQL documentation. There is lots of information available but finding the appropriate bit can be quite tedious and it often requires looking in multiple places.

A lot of other software has such books, but for some reason MySQL seems to be missing one.

A recent example comes from a “documentation feature request” I posted today: http://bugs.mysql.com/bug.php?id=68171. MySQL 5.6 provides a way to “move InnoDB tables” from one server to another. There are many reasons why you may want to do it, but the documentation is currently rather sparse. A simple “example recipe” for this would be good, as would an equivalent recipe for other engines where you can do this such as MyISAM. This is just an isolated …

On Monday afternoon, Neal Armitage and I will be speaking at Percona Live in London. It will be a three hours tutorial about Tungsten replicator.

The contents of this tutorial are mostly new. We have released recently a new and easier way of installing different topologies, in the shape of cookbook scripts, which are distributed with the replicator tarball.

Using this cookbook, any user can simply install multiple topologies, from the simple master/slave to all-masters, fan-in, and star.

There are recipes for showing the replication cluster, switching roles between master and a chosen slave, taking over MySQL replication, installing direct slaves with parallel replication, testing each topology, and uninstalling all.

All the above will be demonstrated during the tutorial, with the addition of conflict prevention and more management …

I have been asked many times to provide an easy way of deploying fan-in and star schema replication schemas. So far, I have been delayed by more pressing duties.

Now the time has come. Since we are about to release a new version of Tungsten Replicator, I made the effort of putting together the steps for an easy deployment.

Recipes

The package (with downloads and svn code available at Tungsten-Replicator Toolbox) includes some juicy goodies. There are recipes to install.

• Master/slave, the classic replication topology. Nothing fancy, but with the tools mentioned in the next section, it becomes as valuable as the other topologies.
• All-masters. This is the Tungsten no-SPOF topology. Every node is a master, and every node has a …

One lesson learned in more than two decades working in this industry is that most of the IT professionals are impatient, want to achieve results immediately, and, most importantly, they don't read documentation. Much as the average geek is happy to answer many requests with a dismissive RTFM, the same geeks are not as diligent when it comes to learning about new or updated technologies. For this reason, there is a kind of documentation that is very much appreciated by busy and impatient professionals: cookbooks. And I am not talking about food. Geeks are not known for being cooks (1) and they like fast food. I am talking about collection of technical recipes, short articles where a problem is briefly stated, and a direct solution is shown. Working with Tungsten Replicator, I am constantly amazed at all the things you can do with it, and at the same time, I am amazed at how so few …

MySQL is an easy database to get running initially but it can be tricky to run in demanding environments. High Availability MySQL Cookbook is a relatively thin book packed with information.

The first four chapters are on the care and feeding of a MySQL 7.x Cluster. It starts simply with an initial configuration, covers backups & replication, covers user defined partitioning, and covers troubleshooting node failures. The examples are short, to the point, and devoid of any unneeded filler.

Next come chapters on replication including the very tricky Multi Master Replication. Used shared storage is covered in a separate chapter from DRBD. The book finishes strongly with performance tuning.

The good points -- the book is concise and not padded with filler. The bad is that it is too short. Considering how well the …