A review of Tungsten Replicator: Part 1 – Installation
THE WORLD DISCUSSES #PYTHIAN ON TWITTER. HAVE A QUESTION? USE OUR HASHTAG AND ASK AWAY.A review of Tungsten Replicator: Part 1 – InstallationPosted by Ben Mildren on Sep 1, 2011

I’ve been following the development of Tungsten Replicator for quiet some time now, and recently was fortunate enough to find the time to take a look at the product in more detail.

If you haven’t heard of Tungsten Replicator yet, it’s an open source database replication engine that can be used to complement or completely replace native MySQL Replication.  In addition to providing standard replication functionality, Tungsten Replicator introduces exciting new features such as global transaction IDs, heterogeneous replication from MySQL to Oracle and Postgres, parallel replication, and the ability to replicate from multiple masters to a single slave.

Giuseppe Maxia and Robert Hodges have been writing some excellent blog posts on Tungsten, providing great detail on both the architecture and functionality of the product.  One of Giuseppe’s recent posts (here) detailed a new simplified installation procedure so this seemed like a natural place to begin…

Just as an aside, I’m a big fan of VirtualBox when it comes to testing on my laptop.  I’ve created several base images which I select from depending on the task, and simply create a new virtual machine by cloning one of these images.  I used to do this using a combination of VBoxManage clonehd and the VirtualBox gui, but with the release of VirtualBox 4.1 this has been simplified with the introduction of the command clonevm, and it can now be achieved through a simple gui wizard or by executing the following command:

VBoxManage clonevm VirtualMachineName --name NewVMName --register

Additionally VirtualBox provides functionality to take a snapshot of a virtual machine, which makes testing different scenarios and rolling back changes very simple.

Anyway back to installing Tungsten.. ..I looked at Giuseppe’s instructions, and began working through the list of prerequisites.

The first prerequisite was to select a Unix-like operating system, using VirtualBox, I chose a 64bit install of CentOS 5.5 as my base image, and cloned and fired up three vm’s.  The image already had MySQL 5.5 installed, and to simplify testing I set SELinux to permissive and turned off iptables, also for ease, I assigned each vm a hostname (tungsten1, tungsten2, & tungsten3) and added the references to the /etc/hosts file.

The second and third prerequisites specify some required packages, I downloaded and installed the 64bit jre rpm from www.java.com/en/download/, and installed ruby and ruby-libs using the CentOS updates repository.

Next on the list was to create a user account to install and run Tungsten.  The prereq’s specify the user needs sudo access, ssh access to the other hosts involved, and read access to the MySQL binary logs.

For the purposes of the test, as the root user I created an additional user on each machine with access to the required group as follows:

[root@tungsten1 ~]# useradd tungsten -Gmysql
[root@tungsten1 ~]# passwd tungsten

I then edited /etc/sudoers and added:

tungsten ALL=(ALL)    NOPASSWD: ALL

Then logging in as the user “tungsten”, I setup the ssh access:

[tungsten@tungsten1 ~]$ ssh-keygen
[tungsten@tungsten1 ~]$ ssh-copy-id -i ~/.ssh/id_rsa.pub tungsten2
[tungsten@tungsten1 ~]$ ssh-copy-id -i ~/.ssh/id_rsa.pub tungsten3

Finally I created the mysql user and ensured the binary log was enabled.

mysql> create user tungstenmysql identified by 'tungsten';
mysql> grant all privileges on *.* to tungstenmysql with grant option;
mysql> flush privileges;
mysql> show global