System under test - overview

Read this introduction and overview of an IBM® Cognos® Business Intelligence (BI) server solution for Linux™ on System z®, and how it was implemented as a system under test (SUT) for this project.

The SUT includes basic IBM Cognos BI core components like a Content Manager, application tier components like Report Servers, and a Gateway.

The architecture model consists of logical tiers distributed across three independent systems:

• Client components on local workstations (tier one)
• Cognos BI server components on remote servers (tier two)
• Back-end database server on a remote server (tier three)

Tier one is responsible for the presentation and user interaction with tier two processes. The client components enable the user to interact in a secure manner, by using Cognos BI APIs to access the tier two servers. Tier one client processes never access any tier three services on the database servers directly. Tier one could either be a web browser, a Cognos Mobile iPad application, or a custom client using the Cognos SDK to generate transactions against Cognos BI.

Tier two processes are also known as application logic layer. These processes manage the business logic of the application and provide access to tier three services. It is the layer where most of the data processing occurs. The Cognos BI Gateway and Report Servers represent the application logic layer for this setup. The Report Servers run under the control of a WebSphere® Application Server (WAS), while the Gateway extends an IBM HTTP server.

Tier three services are protected from direct access by any tier one components. Usually they are residing in a secure network (inside the System z box for example). Interaction is only possible through the tier two services. The Cognos meta data repository, called the Cognos BI Content Store, and reporting databases (DB2® LUW or z/OS®, SQL server) which store the content to be analyzed, are considered as tier three services in this case.

The system is implemented in a single IBM System z LPAR in a virtualized z/VM® environment. The IBM Cognos BI core components are distributed over four virtual machines and are combined in a WAS Network Deployment cell. The application servers and the HTTP server in the cell can be managed with the WAS Deployment Manager.

The Content Manager database and the BI sample data database run in two virtual machines with IBM DB2 software.

The competing workloads are set up in two virtual machine triplets and one single DayTrader combo system. The virtual machine triplets form a complete DayTrader software stack including an IBM HTTP server, a WAS server running the DayTrader application, and a DB2 database server. The DayTrader combo virtual machine includes all application components in a single instance.

For guest-to-guest communication, the z/VM guests are connected over a Virtual Switch (VSWITCH), which also provides LAN access via a 10Gbit OSA-E card.

An IBM Flex System® blade is used as a Cognos BI and DayTrader workload generator. The IBM Flex System blade is connected over the 10GbE network to the IBM System z mainframe.