July 2, 2012 | Written by: IBM Cloud Staff
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By Addison Goering
Earlier this year, IBM released its IBM PureSystems family of products. There are two products in this family: IBM PureFlex System and IBM PureApplication System. In very simple terms, the PureSystems family can be thought of as cloud capabilities on a rack. Generally, cloud solutions include computing power, storage, and networking capabilities. PureFlex System provides all these capabilities on a freestanding rack. PureApplication System also provides those same capabilities, but with some additional “built-in smarts,” such as deployment models and built-in monitoring that differentiate it from PureFlex System. PureApplication System has the included capability to build middleware topologies, application environments, and custom virtual images. Very powerful indeed!
Three technical deployment models (patterns) are supported by PureApplication System:
- Virtual systems
- Virtual applications (which includes database applications)
- Custom images
Each model has its own capabilities and is used in specific situations.
Virtual system patterns are the easiest of the deployment models to understand. If you are familiar with WebSphere Application Server topologies, virtual systems make complete sense. Virtual systems, in their most basic form, are simply middleware topologies. In this picture, you can see that PureApplication System is preconfigured with a number of catalog parts.
Catalog parts are glued together to build virtual system patterns. In this example, three catalog parts (deployment manager, custom node, and DB2) were chosen from the list on the left side and glued together to make a virtual system pattern. Also, two scripts were added to the deployment manager. Scripts are executed when the virtual system pattern is deployed. In this example, a server and data source are created when the virtual machine is deployed.
There are also preloaded “best practice” virtual system patterns. They can be used “as is” or as a starting point for creating custom virtual system patterns. Looking through the list, you can see several common patterns: DB2 Enterprise, a WebSphere advanced cluster, and a WebSphere development cluster.
After you have created a virtual system pattern or worked with one of the preloaded patterns, the next step is to deploy the pattern to the “cloud.” The cloud is part of the environment available to you with PureApplication System. Deploying is as simple as a click of the button. PureApplication System takes care of allocating the appropriate hypervisors, storage, and networking capabilities. After a virtual system is deployed, each catalog part is represented by a virtual machine. In the example shown here, you can see that a large topology WebSphere cluster was created.
There is one deployment manager, 10 custom nodes, and four Web servers. This pattern will create a total of 15 virtual machines when deployed. Each virtual machine can be managed from PureApplication’s workload console.
Virtual applications are the next deployment model. Two types of virtual application patterns are available: WebApp pattern and database pattern. The first point to remember is that a virtual application is very different from a virtual system. As the name implies, virtual application patterns are application centric. Virtual systems are topology or system centric. The application parts for a virtual application are created outside of PureApplication System. In this picture, you can see there is an EAR file representing the enterprise application, a DDL file representing the data structure needed for the database, and an LDIF representing the users and groups in the LDAP.
Using the Virtual Application Builder, you graphically assemble a virtual application pattern by dragging components, such as EAR files, DDL files, and LDIF files, to the canvas. After these components are dropped onto the canvas, you can create linkages between the components. After all the linkages are made, the WebApp pattern is ready to deploy.
Just like a virtual system, PureApplication System handles allocating the appropriate cloud resources for the virtual application pattern. When the pattern has been deployed, it can be managed from the workload console. As you can see from the picture, there are two perspectives into this virtual application pattern. You can see the pattern from either a middleware or virtual machine perspective. Each component is allocated its own virtual machine. In the next picture, these application parts make up the WebApp pattern.
The other type of virtual application is a database pattern. The database pattern is created and managed independently of any virtual application pattern. You can think of it as a standalone database that can be accessed by any application, but is deployed and managed in the cloud. When you create a database pattern, options are available to create it either for online processing or data warehousing. As you create a database, you determine how much space it should consume and where the schema file is located.
When the database is deployed, it uses the appropriate amount of space and creates the schema. Similar to other patterns, after it is deployed, the virtual machine that is created automatically is managed from the console.
Custom image is the final deployment model. Custom images give you complete control over the structure of the virtual image and its contents. This control is desirable for many corporations because corporate policy might dictate what is placed on virtual images and how they are built. To provide custom images to PureApplication System, you must use an external tool called IBM Image Construction and Composition Tool (ICCT). See the next figure. With ICCT, you can select virtual images from a corporate virtual image library. The image you select has the base operating system already loaded on it. Additionally, a software specialist creates a bundle that encapsulates intelligence about the image’s software components by including installation tasks, configuration tasks, and clean-up tasks. An image builder next defines the image’s parameters within ICCT and combines the OS and the bundles into an OVA file. The OVA file is then exported to PureApplication System. After it is imported, the virtual image is available for use.