14.1.3 Creating the Plants by WebSphere appserver

In a distributed server environment, you have the option of using a single appserver, or creating multiple appservers or clusters.

The advantages of deploying multiple applications to a single appserver is that it consumes less resources. There is no overhead for any extra appserver processes. Another benefit is that applications can make in-process calls to each other. For example, servlets in one EAR file could access Local interfaces of EJBs in another EAR file.

One alternative to using a single appserver is to deploy each application to its own server. The advantages of deploying only one application on an appserver is that it gives you greater control over the environment. The JVM heap sizes and environment variables are set at appserver level, so all applications running in an appserver share the JVM memory given to the appserver and they would all see the same environment variables. Running each application in its own appserver could also make it easier to perform problem determination. For example, if an application runs amok and consumes a lot of CPU, you could see which application it is by looking at the process ID of the appserver.

In our example, we create a unique appserver on which to run the Plants by WebSphere sample application.

For a full discussion of appserver properties, see 4.4, Working with appservers.

To create an appserver...

1.	Select Servers  | Application Servers.

2.	Click the New button and provide the information shown in Figure 14-1.

Figure 14-1 Creating the WebSphere Bank appserver

Node

Select the node on which the appserver will be created.

Server name

Enter the appserver name, such as PlantsByWebSphereServer.

Click Next.

3.

In Step 2, select which server template to use as the base for this new appserver. The DeveloperServer template is used when setting up a server for development use and will cause the JVM to prioritize quick startup (by disabling bytecode verification, and performing JIT compilations with a lower optimization level). This option should not be used on a production server, where long run throughput is more important than early server startup. If you have not created any templates on your own, then select the WebSphere default. Otherwise, select the server template you want to use and click Next.

4.	In step 3, you can select, if you want, WebSphere to generate a unique set of port numbers for this appserver. This ensures the ports defined for this server does not conflict with another server currently configured on this node. Check the Generate Unique Http Ports box and click Next.

5.	On the Summary page, click Finish.