NonStop Systems Introduction

The Application Server Environment

NonStop Systems Introduction—527825-001

3-13

Server Handling

configure two or more server classes for requests of different lengths. By separating

the shorter requests from the longer requests, response time stays fast and consistent

at all times.

Online Reconfiguration

It is sometimes necessary to reconfigure an application. If the system administrator has

to shut down the whole system each time it is necessary to add or redistribute servers

or add clients, the application and the system both fail to meet the fundamental ZLE

requirement of continuous availability. From the business user’s point of view, the worst

time to bring down the application is when users need it most. Figure 3-8 on page 3-13

shows how the application server permits online reconfiguration.

As shown in Figure 3-8 on page 3-13 the application server permits online

reconfiguration of applications. The application continues to run while the administrator

reconfigures the application, using tools and programs provided by the application

server. For example, in the WebLogic Server environment, the administrator uses the

Web-based Administration Console to reconfigure the servers of an application. The

Administration Console provides a graphical user interface that simplifies the server

management tasks.

Figure 3-8. Online Reconfiguration

Application server environment

VST023.vsd

Servers

Clients

Dynamic reconfiguration of online environment:

! Add or redistribute servers

! Manage communications links between clients and servers

Process and link

management

services

Administrative interface