Order out of disorder:
Multiple personalities can be a good thing
by David Ross
With the introduction of IBM SmartCloud Provisioning 2.1 in early August 2012, IBM has provided much more than a simple “next version” improvement to an existing product, but has rather transformed a basic cloud platform into a total solution that provides not only a cloud environment, but tools for simplifying the understanding, creation, and management of the images that will run in the cloud. Included in version 2.1 are the IBM Image Construction and Composition Tool, (ICCT) and the IBM Virtual Image Library. These two components complement each other and provide a solution for creating, managing, and controlling images in your environment.
This article will discuss the concept of an image 'personality' in more detail and how it will reduce the number of master images needed to deploy applications and instances into a cloud. Personalities are a new concept introduced with the version of the Image Construction and Composition Tool included with IBM SmartCloud Provisioning 2.1.
Many shops have standardized on a common set of operating systems (OS) for use with their deployed application infrastructure. Further, a common set of applications that run on these various OS platforms has also been established, such as databases, monitoring agents, HTTP servers and so on. For example, suppose you are a shop that has settled on a particular distribution of Linux, and you have three common applications (database, server, messaging) that run on it. Your company has decided to move some of your infrastructure to a cloud-based environment.
In the past, such a situation would require the platform and application specialists create three master images – one for each of the applications for this particular OS. Each of these master images would have to be maintained, patched, and updated independently, even though they share a common base operating system, shared libraries and so on.
In a previous posting it was shown that maintenance of the individual applications is greatly simplified through the use of bundles, which encapsulate everything needed to deploy an application onto an OS. However, using image personalities in ICCT, these three master images could be further collapsed into a single master, reducing the maintenance requirements even further. A single common master image could be assigned three personalities, and during deployment in SmartCloud Provisioning, the personality of a given instance derived from that master would determine its behavior in the cloud.
Simply put, a personality is a set of custom configuration settings for a subset of software bundles in a virtual image. The multiple-personality master image is created by installing all the potential software bundles in the image. During deployment, only the software bundles that are included in the desired personality are configured, according to the deployment parameters specified in the personality. In this manner, the single master image can be used multiple times - even in the same application pattern - but with the different personalities used in different places. In other words, the same master image can be used to deploy a database server, complete with listening ports and defined users in one case, and can become an application server, with totally different settings applied, in another.
Now, you are responsible for only one master image. OS or application patches can be applied once to a master image, instead of three times in our example. If you need to update the database application, again, you are updating a single master image. The potential for 'drift' in master images is reduced as well, since only one master is in use instead of multiple, almost-identical copies.
This simple example only illustrates the potential of this solution. You can imagine the potential savings and reduction in master image counts and maintenance when you multiply the number of OS platforms, applications and combinations that might exist in a typical production environment. Personalities for master images is only one of the new features found in SmartCloud Provisioning 2.1.
For more information, visit:
·The infocenter for SmartCloud Provisioning 2.1
·What's new in SmartCloud Provisioning 2.1 (developerWorks)
David Ross has worked for IBM for over 13 years and is currently a Senior Technical Enablement specialist with IBM Software Services for Tivoli in the Cloud space. He can be reached at firstname.lastname@example.org or @TechnoRoss on Twitter.