#### Implementation Pattern

### Enterprise Web Application

#### Description

The Enterprise Web Application pattern extends the Lightweight Web Application pattern by adding an Application Server. The application server provides additional services to the web applications such as messaging, transaction management, resource pooling and load balancing.

#### Applicability

This pattern is most applicable when an online transaction system has a very large, and possibly fluctuating, user base. It provides the scalability needed for large sets of users without sacrificing the benefits of the 3-Tier approach

#### Related links

- Pattern Catalog