Thoughts of virtualization – Part III

Ok, it’s been almost 24 hours since I started my serious playing around with Amazon EC2, and I can honestly say that I’m tired – however, I’m very pleased with my results. Like any other experiment, this one started with a requirement. The requirement was to install and operate one of the dialer frameworks I’ve written in the past year on an EC2 based instance. In order to evaluate the process, let’s start with our baseline installation, meaning, what am I using in the real-world:

Hardware and Software Specification

The original machine answered to the following specification: Quad Core CPU, 2GB of RAM, 250GB of Hard Drive. My original machine was running CentOS 5.2 with an x86_64 kernel installed. In terms of software installed, we had Asterisk 1.4.22.1, MySQL 5.X, PHP, FreePBX, Apache and my dialer framework.

Introducing Amazon EC2 AMI

An EC2 AMI is basically an image of a computer, contained with a single installation manifest on the Amazon cloud computing system. AMI’s provide for the simplest manner to start using EC2, as these usually include a pre-defined server installation, that usually has some stuff already installed.

Choosing your AMI

Amazon provides a multitude of AMI’s to work with, unfortunately, most of these are either out-dated and the sheer number of these makes the choice somewhat overwhelming. I decided to start working with a working AMI image of Fedora Core 8, that already had the LAMP stack installed – the one I used was:

LAMP Web Starter
LAMP Web Starter (AMI ID: ami-ba4eaad3)
Fedora Core 8, 32-bit architecture, PHP 5.0.4, Apache 2.0.54, and MySQL 4.1.20

The YUM Repository issue

For some strange reason, the AMI images contained in the Amazon repository are all unable to perform any updates to their installed RPM packages. It took me a while to understand what’s wrong, but in general, the fedora project had simply removed the old releases from their repository, so I had to go in and manually modify the /etc/yum.repos.d/ configuration files. For you convenience, here is the repos list that I’m using at this point:

YUM Repositories for Amazon EC2 Fedora images <- click this to download the file

[development]
name=Fedora Core $releasever - Development Tree
baseurl=http://archives.fedoraproject.org/pub/archive/fedora/linux/core/development/$basearch/
enabled=1
gpgcheck=0
[extras-development]
name=Fedora Extras $releasever - Development Tree
baseurl=http://archives.fedoraproject.org/pub/archive/fedora/linux/extras/development/$basearch/
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-extras
gpgcheck=0
[extras]
name=Fedora Extras $releasever - $basearch
baseurl=http://archives.fedoraproject.org/pub/archive/fedora/linux/extras/$releasever/$basearch/
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-extras
gpgcheck=1
[updates-testing]
name=Fedora Core $releasever - $basearch - Test Updates
baseurl=http://archives.fedoraproject.org/pub/archive/fedora/linux/core/updates/testing/$releasever/$basearch/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-test
[updates-released]
name=Fedora Core $releasever - $basearch - Released Updates
baseurl=http://archives.fedoraproject.org/pub/archive/fedora/linux/core/updates/$releasever/$basearch/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora
[base]
name=Fedora Core $releasever - $basearch - Base
baseurl=http://archives.fedoraproject.org/pub/archive/fedora/linux/core/$releasever/$basearch/os/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora

If you are trying to install an instance, you may use the above for any Fedora based AMI on EC2.

Creating my own AMI

While going about and building a single server is fun, I needed a way to create my own installation AMI once I’ve completed my modifications. The Amazon EC2 resources website gives out a whole lot of information, which can be somewhat confusing for the first time reader. So, I searched for a better way to construct my own AMI image. I found the following web page, which was really really helpful: Azeez’s Notes.

Azeez’s blog gives a very concise and to the point, step by step, guide to building your own AMI image – it got me up and running in less than 10 minute – WAY TO GO AZEEZ.

So far, so good …

So far my installed instances are working just fine and I’m currently operating a cluster of a few of these dialer systems. I’m in the process of checking what kind of mileage I’ll get from the EC2 instances, in comparison to a real hardware server – which is really interesting.

My main objective here is to be able to build a dialer-on-demand framework, which will enable my customers to increase their capacity utilizing a simple web interface to initiate my AMI instances. I’ll report back with additional information once I have it.

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