System under test (SUT) overview
This section describes the two IBM WebSphere Application Server (WAS) scenarios and how their software and hardware components interact.
The first scenario is a WAS only setup. WAS uses its own internal HTTP transport service in this case. The second scenario uses IBM HTTP server (IHS) as HTTP transport instead. Both scenarios are configured to support a SSL connection between the client and the application server. For the second scenario IHS is configured for SSL support.
WAS provides the application logic layer in a three-tier architecture model, enabling client components to interact with data resources and legacy applications.
The logical tiers are typically distributed across three independent systems:
- Client components running on local workstations (tier one)
- Application servers running on a remote server (tier two)
- Database servers running at the backend on a remote server (tier three)
However these tiers are logical and might or might not be running on the same physical system.
Tier one is responsible for the presentation and user interaction with the second-tier processes. The client components enable the user to interact in a secure manner, for example by using a secure network communication to access the second tier applications. The tier one client processes never access any tier three services on the database server directly.
In the SUT, tier one is a System x® client system running a workload driver accessing sample online transaction data provided by the application server.
Tier two processes are also know as application logic layer. These processes manage the business logic of the application and provide access to the tier three services. It is the layer where most of the processing work occurs. The benchmark application used for this test emulates a Online Stock Trading System.
Tier three services are protected from direct access by the client components. Usually they are residing in a secure network (for the SUT inside the IBM® System z® system). Interaction is only possible through the second-tier processes.
For more information, refer to the WAS Version 8 information center:
https://www.ibm.com/docs/en/was/8.5.5