2.6.1 Dynamic operations: WebSphere Virtual Enterprise

WebSphere Virtual Enterprise is a feature of WebSphere XD that provides a set of application infrastructure virtualization capabilities. It is designed to deliver dynamic operations through two key capabilities:

Virtualization of WebSphere environments

Introduction of a goals-directed infrastructure

A virtualized WebSphere environment allows you to expand your solution as business needs dictate through the dynamic allocation of WebSphere resources.

WebSphere XD implements a virtualized environment by creating pools of resources that can be shared among applications, thereby optimizing utilization and simplifying overall deployment. As resources are needed for expected and unexpected spikes in workload demand, application resources can be allocated to where they are needed most. Allocating resources on an on-demand basis enables better use of computing resources that you already own and, potentially, might allow you to run more applications on the LPARs that you already have in place.

Planning a production environment for dynamic operations is different than planning one for a static environment. In a static environment, you have dedicated servers for each application.

To size the servers, take a look at your applications, the requirements, and the expected load during peak time. Your production environment must be prepared for the load during this (possibly, short) period. This means that, during non-peak hours, your servers are underutilized.

In general, a company has more than one critical application. It is likely that the second application has its peak load at a different time of the day. In a static environment, the servers hosting the first application cannot be used for the peak load of the second application. Therefore, the quality of service (QoS) might suffer or you need more or bigger systems to ensure QoS.

To guarantee a good QoS, one possibility would be to add additional nodes. However, doing so would increase the cost and would not solve the underlying problem. In this case, the problem is that you cannot share your resources and thus optimize utilization.

The following list of questions help you gather the information required to set up an environment for dynamic operations:

What applications do you want to include?

This affects the number of node groups and dynamic clusters.

What are your critical applications?

This affects the allocation of applications to dynamic clusters and the assignment of service policies.

Are there applications that should not run on the same LPAR?

These LPARs have to be in different node groups.

Which applications can share the same server configuration?

These can be in the same dynamic cluster.

Which servers and hardware do you want to include?

In a heterogeneous environment it could be interesting to have multiple node groups, dependent on the hardware type.

Do all servers have the same resources available, such as network drivers, database connections, external drives, additional software?

Because every application can be started on every node in a node group, have all resources available on each node. You must take this into consideration because it might increase license costs and possibly require additional hardware resources on each LPAR.

Based on this information, you should be able to plan your node groups, dynamic clusters, and service policies.

Sharing resources among applications helps to optimize utilization and simplify deployment. WebSphere XD redefines the relationship between traditional J2EE constructs. Instead of deploying applications directly onto an application server, you can map an application into a resource pool. This application can then be deployed on some subset of servers within that pool according to your configured business goals. The WebSphere XD virtualized infrastructure is predicated on two new constructs: node groups (which represent resource pools) and dynamic clusters, as explained in the following sections.

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