When many people think of cloud computing they immediately think of virtualization and virtual machines in particular. This is completely natural and not at all surprising. After all, one of the core underlying technologies necessary for cloud computing is virtualization. However, it is important not to confuse one element of cloud computing with the entire thing - and this can sometimes happen. Many people have begun to leverage virtual machines in their on premise environment and sometimes begin to call this their private cloud. While virtualization is a substantial step forward and help gets you started down the necessary path of standardization and automation that is essential in a cloud - it is not in and of itself "a cloud".
The National Institute of Standards and Technology has published its definition of cloud computing. This is a very complete and yet concise definition that includes not only the essential characteristics of a cloud solution but also the service models (IaaS, PaaS, SaaS) and deployment models (public, private, hybrid, community). It is a great way to get a perspective on cloud and can be useful when considering the solutions of various vendors.
Let me summarize the essential elements of cloud from this definition here:
broad network access
So, this is interesting. Not only is this much more than just virtualization - but virtualization isn't even mentioned in the list explicitly. Not to worry - virtualization is of course important and is included under the resource pooling topic. I would assert that virtualization is also necessary to facilitate the type of on-demand, self-service, elastically scaling resources that are leveraged in a cloud. What is crystal clear from this definition is that there is a lot more to a cloud solution than just virtual images and some hypervisor infrastructure upon which to run them. Somebody must provide the necessary on-demand/self-service capabilities, the network access to these services, the management of the resource pools, enabling true elasticity for running systems, measuring services and so forth. IBM Workload Deployer provides just such capabilities for the on-premise cloud allowing you to efficiently deploy patterns built for virtual systems and virtual applications with deep knowledge of the middleware that is being provisioned to optimize these solutions. Furthermore, Workload Deployer provides the complete lifecycle management from pattern creation, to deployment and provisioning, applying maintenance, resource and license management in the on-premise cloud, elastic scalability, and eventually returning resources to the on-premise cloud to be reused. Workload Deployer is a complete solution for not only server virtualization but of course for cloud computing.
However, virtualization doesn't have to stop with just virtual machines. It is a general principle that can be applied to more than just servers. At its core, virtualization is really about providing a level of abstraction between some real resources and the consumers of those resources. This is a natural fit when we think of server virtualization and virtual machines. However, there are also substantial benefits to be gained by adopting a similar abstraction between the middleware and the applications themselves - sometimes referred to as application virtualization.
By application virtualization I mean providing the capabilities to abstract the application from the underlying infrastructure such that it can be elastic, participate in health management policies, and provide agility across the pool of application infrastructure resources. This type of application virtualization is built into our Virtual Application pattern (hence the name) in Workload Deployer and surfaced in solutions via policies (such as scaling and routing), and high availability functions built into the Web Application pattern type. For Virtual Applications these features are fully integrated and optimized functions as are all elements of Virtual Applications. However, similar features have also been available for WebSphere Application Deployments in Virtual System patterns with a special extension.
WebSphere Virtual Enterprise provides application virtualization for traditional WebSphere ND solutions and this same feature is delivered for Virtual System pattern deployments of WebSphere Application Server by use of the Intelligent Management Pack. Leveraging the capabilities of Workload Deployer with Virtual Systems lets you gain the benefits of server virtualization and to reduce hardware, provide rapid and consistent deployment of entire systems, dynamically adjust resource consumption, and much more. Leveraging the capabilities of the Intelligent Management Pack provides the ability to manage service level agreements with elastic scaling and health management, lower operational costs, and provide for improved application management. These two solutions together provide a powerful combination to improve the management and resiliency of your enterprise applications.
If you would like to learn more about application virtualization using the Intelligent Management Pack in conjunction with Virtual System Patterns in IWD then please join Keith Smith and myself tomorrow for a webcast on this very topic. Keith is the lead architect on our WebSphere Virtual Enterprise and Intelligent Management Pack products and brings a wealth of experience in this space. So don't miss this opportunity - register here.
Lately, I have run into multiple situations where an IBM Workload Deployer user has been trying to decide exactly how they want to create their customized images for the cloud. Essentially, they have been trying to decide whether to use the native extend and capture capabilities of IBM Workload Deployer, or to pursue the use of the Image Construction and Composition Tool (also included with the appliance). The conversations have been interesting and challenging, but more importantly, they have been a reminder that constructing enterprise-ready environments for the cloud does not happen by magic. It takes thought, deliberate planning, sustainable design, and the tools to carry everything out.
The tools part we have covered. I have every confidence, bolstered by user experience after user experience, that IBM Workload Deployer and associated tools (like the Image Construction and Composition Tool) equip you to build highly customized, cloud-based application environments. In this post, I want to focus in on the thought process that goes into how you decide to build your customized environment. Specifically, I would like to talk about important points to consider as you try to understand whether to use the native extend and capture capabilities of IBM Workload Deployer or the Image Construction and Composition Tool.
To be clear from the outset, I am not trying to provide a decision flowchart in this post. For all intents and purposes, that would be next to impossible. Instead, I want to pose to you some important questions that you should ask of yourself, along with the reasons why I believe those queries to be important. Keeping in mind that this is not an all-inclusive list, here it goes:
Question: Are the customizations that you want to make congruent with an IBM-supplied image?
Reason: One of the first decisions you should make is whether or not you can start with an IBM-supplied image as the base for your customization. You need to know what middleware elements (type and version) make up your environment and what operating system should host that environment (version and distribution). You can match that information against the list of content that IBM supplies. If there is a match, you should start by looking at extend and capture to customize that image to meet your needs. If there is no direct match, you may be looking at the Image Construction and Composition Tool.
Question: Does your custom content supplement middleware content supplied in an IBM image?
Reason: If you simply need to add additional components that supplement software already in an IBM image, I believe it is best to first examine the use of extend and capture. Whether these components are IBM software or not is irrelevant as the extend and capture functionality does not care.
Question: How configurable do you want to make the custom content in your image?
Reason: If you are adding content into the image, you need to think about just how configurable you need it to be. When you use extend and capture, you add the content to an existing image in a manner that pretty well ends up being opaque to IBM Workload Deployer. To configure that content, you need to have script packages and make sure they are part of every pattern you create based on the image. Alternatively, if you use the Image Construction and Composition Tool, you can embed configuration behavior in the image's activation engine, and you can expose deploy-time parameters without needing to include script packages in every single pattern. As an example, if you need to add a monitoring agent into your environment, you would likely do this via extend and capture and end up with a pretty simple script package to configure that agent during deployment. If however, you need to create an image with a custom database, you would likely favor the Image Construction and Composition Tool as you could embed common deploy-time configuration parameters directly in the image. For a database, there are likely to be many more deploy-time configuration parameters that you want to expose as compared to a more simple monitoring agent.
Question: Is your main focus on making operating system changes?
Reason:If your primary focus is on making operating system changes AND the answer to the first question is that your target content aligns well with IBM-supplied images, then extend and capture is where you want to start. Of course, you need to make sure that you can make all necessary changes to the OS with extend and capture, but I will say that this capability is not very restrictive at all.
Admittedly, this is a short list, but I believe it is a good starting point for how you decide upon one approach versus the other. Also, I would be remiss not to point out that these tools are absolutely not mutually exclusive. Many users I work with use a combination of the two approaches. In fact, there are some use cases that call for both tools. Start by creating a completely custom image in the Image Construction and Composition Tool, and then subject that image to the extend and capture process in IBM Workload Deployer to customize it for a particular purpose, team, project, etc. I hope you find this helpful, and I welcome your feedback or thoughts!
We've been talking a lot recently about Virtual Application Patterns and enhancements to this deployment model in IBM Workload Deployer v3.1. This is appropriate because virtual applications are a substantial evolution for application deployment in a private cloud. Virtual Application Patterns deliver on the promise of Platform-as-a-Service - letting you focus on the application while Workload Deployer builds the necessary platform to deploy and manage your application.
However, Virtual System Patterns are still alive and well ... and quite frankly, this is where many people begin to explore the functionality provided in Workload Deployer. For many, it is a logical first step to start recreating familiar physical environments in the private cloud and then leverage these environments to develop and test their applications. It is also a great way to build out new applications using familiar concepts, leveraging existing scripts, and take full advantage of the agility, consistency, and increased resource utilization available in a Workload Deployer managed private cloud.
You may recall that virtual system patterns are sometimes called topology patterns because they are used to define a topology middleware configuration to meet application requirements. With a virtual system pattern you define exactly the type of middleware configuration that you need for your application environment and Workload Deployer provisions exactly that configuration when the pattern is deployed to your private cloud.
To use an automotive analogy, you might compare virtual systems to building your own hot-rod from a molded frame while virtual applications are more like purchasing a complete vehicle from a dealer. When you purchase a vehicle from a dealer you receive a fully functional automobile. Sure, you can choose the color and some options – but you don't necessarily know the details of all of the components that make your vehicle functional. Just add a driver (you) and off you go! This saves you substantial time and money while freeing you from the need to be an automotive engineer. As with the production vehicle, virtual applications are optimized for a specific purpose and are extremely effective when used for that purpose. All you need to do is add your application (the driver) and run-time requirements. Virtual system patterns are like the hot-rod approach. You start with a modeled frame of sorts (hypervisor edition images) – thereby saving time and effort so you don't have a start from scratch. However you still have the responsibility and flexibility to create a very unique custom vehicle. Doing so requires more expertise and a greater time investment when compared to a production vehicle (virtual application), but you get to decide all of the details. With virtual systems you specify the exact vehicle you need for your application. This provides substantial flexibility but requires a deep knowledge of the middleware and an investment of time building necessary scripts and other elements to support your application environment.
So as I mentioned, virtual system patterns are very popular. And if you have been following recent posts about the enhancements delivered in IBM Workload Deployer v3.1 you noticed that several of the features primarily focused on virtual applications have at the same time been extended to virtual system patterns - such as the shared caching service and the new base AIX image. So we certainly consider virtual systems deployment model to be important. IBM Workload Deployer v3.1 delivered new hypervisor edition images and the IBM Image Construction and Composition Tool was bundled with Workload Deployer - primarily used for creating custom images to leverage in virtual system patterns. The IBM Image Construction tool is a substantial advancement in the ability to create your own custom base images.
To help communicate that we haven't been neglecting virtual system deployment patterns, I created a new demo to highlight this deployment model. The demo begins by providing a quick overview of the components that go into a virtual system pattern. It then shows how to clone a pattern to customize it for your own purpose, deploy it, monitor licenses, and monitor resource usage in your private cloud. Finally, it shows a quick demonstration of installing an emergency fix to a deployed virtual system instance.
I'll be showing this and other demos at IBM Pulse 2012 next week. I hope to see you there!