In BMC Server Automation, the primary component of the middle tier is the Application Server, which controls communication between the console and remote servers. Not only does the Application Server manage communication between consoles and remote servers, it also controls interaction with the database and file servers.
The Application Server is completely scalable, allowing administrators to adjust its performance to accommodate added users and increased database activity. If necessary, a BMC Server Automation system can incorporate multiple Application Servers that cooperate by balancing job processing workloads.
The middle tier also includes several components used for provisioning servers, with the principal components being the PXE Server and the Application Server. The PXE Server delivers instructions to servers being provisioned so they can download a bootstrap program. The Application Server provides servers being provisioned with the instructions necessary to provision the machine.
If a site has installed BladeLogic Portal, the middle tier includes the BladeLogic Portal server and a database for the portal. The BladeLogic Portal server processes communication and user interactions between the web interface, the BMC Server Automation Application Server, and the portal database.
If a site is running BMC BladeLogic Decision Support for Server Automation, the middle tier includes an Apache Tomcat server. BMC BladeLogic Decision Support for Server Automation uses the Application Server to authenticate users, and it reads data from the core BMC BladeLogic database as well as a reporting data warehouse. The reporting data warehouse is populated using information from the core BMC BladeLogic database.
Network Shell can optionally incorporate a middle tier component — an Application Server that is configured to run a Network Shell proxy server. Operating as an intermediary between Network Shell clients and the managed servers, the Network Shell proxy server authenticates Network Shell client users.