Tips for WebSphere v5 Network Deployment Administrators @ JDJ

The WebSphere Application Server Network Deployment version 5.0 (WAS ND) provides an infrastructure for you to centrally administer multiple WAS servers, resources, and other elements of your topology. Your managed topology can include support for clustered servers with workload management and failover. WAS ND's support for centrally administering topologies provides significant benefits for both large-scale and small-scale topologies.

This article provides tips to help you better exploit the administrative capabilities of WAS ND. We discuss options for deciding on the scope of your topology, and advice on administering the topology. If you are planning or administering a topology based on WAS ND (or WAS Enterprise), these tips, which are based on lab experiences with large ND deployments, should be helpful.

Tips for Planning Cells

Applications and the resources they require are the key elements in any topology. WAS ND provides flexibility for spreading your applications across cells, nodes, and application servers. There is no magic formula that tells you exactly how to build your cell topology, but your solution needs to combine performance and scalability with your site requirements and administrative processes.

WAS ND allows for many nodes, with multiple application servers on each node and multiple applications in each server. In fact, the WAS ND architecture allows as many as you want. Lab experiments have achieved hundreds of nodes and server elements without experiencing any "hard" limits (see Figure 1).

While large configurations are impressive, they may not be entirely practical for you. As you add elements to your topology, it's logical that you'll experience effects of a larger topology. When you plan your topology, consider the practical limits. In terms of the number of nodes and servers, practical limits include complexities in administering a large topology, as well as physical constraints such as memory and network bandwidth available.

Let's take a look at a few tips for you to consider when you plan your topology.

Place the Deployment Manager on a Dedicated System

The deployment manager for your cell can be co-located on a system with a node agent and application servers. But, sharing a system can introduce contention for system resources and interfere with administration performance. Plus, remember that your deployment manager is your central point of administration for your entire cell, and anything that compromises your deployment manager process also compromises your ability to manage and monitor your cell. Therefore, consider placing the deployment manager on a dedicated system.

Put One or a Small Handful of Applications in Each Application Server

While it is entirely possible to put many, many applications in each server, the more typical and preferred deployment is a single application, or perhaps a small set of closely related applications. Keeping applications separated is best from a standpoint of security, isolation, manageability, and so on.