WebLogic Server

Let's talk a little more in detail about the enterprise application server that is at the core of Oracle Fusion Middleware, WebLogic. Oracle WebLogic Server is a scalable, enterprise-ready Java Platform Enterprise Edition (Java EE) application server. Its infrastructure supports the deployment of many types of distributed applications. It is also an ideal foundation for building service-oriented architecture (SOA). You can already see why BEA was a perfect acquisition for Oracle years ago. Or, more to the point, a perfect core for Fusion Middleware.

The WebLogic Server is a robust application in itself. In Oracle BI 12c, the WebLogic Server is crucial to the overall implementation, not just from installation but throughout the Oracle BI 12c lifecycle, which now takes advantage of the WebLogic Management Framework. Learning the management components of WebLogic Server that ultimately control the Oracle BI components is critical to the success of an implementation. These management areas within the WebLogic Server are referred to as the WebLogic Administration Server,  WebLogic Manager Server(s) , and the WebLogic Node Manager.

A few WebLogic Server nuances

Before we move on to a description for each of those areas within WebLogic, it is also important to understand that the WebLogic Server software that is used for the installation of the Oracle BI product suite carries a limited license. Although the software itself is the full enterprise version and carries full functionality, the license that ships with Oracle BI 12c is not a full enterprise license for WebLogic Server for your organization to spin off other siloed JEE deployments on other non-OBIEE servers. This book is hardly a guide to software licensing, but following are a few of those differences one should keep in mind when beginning or continuing an Oracle BI 12c implementation:

• Clustered from the installation: The WebLogic Server license provided with out-of-the-box Oracle BI 12c does not allow for horizontal scale-out. An enterprise WebLogic Server license needs be obtained for this advanced functionality.
• Contains an Embedded Web/HTTP Server, not Oracle HTTP Server (OHS): WebLogic Server does not contain a separate HTTP server with the installation. The Oracle BI Enterprise Deployment Guide (available on https://www.oracle.com/index.html) discusses separating the Application tier from the Web/HTTP tier, suggesting Oracle HTTP Server.

These items are simply a few nuances of the product suite in relation to Oracle BI 12c. Most software products contain a short list such as this one. However, once you understand the nuances, the easier it will be to ensure that you have a more successful implementation. It also allows your team to be as prepared in advance as possible. Be sure to consult your Oracle sales representative to assist with licensing concerns.

Despite these nuances, we highly recommend that in order to learn more about the installation features, configuration options, administration, and maintenance of WebLogic, you not only research it in relation to Oracle BI, but also in relation to its standalone form. That is to say that there is much more information (books, blogs, and so on) at large on the topic of WebLogic Server itself than WebLogic Server as it relates to Oracle BI. Understanding this approach to self-educating or web searching should provide you with more efficient results.

WebLogic Domain

The highest unit of management for controlling the WebLogic Server installation is called a domain. A domain is a logically related group of WebLogic Server resources that you manage as a unit. A domain always includes, and is centrally managed by, one Administration Server. Additional WebLogic Server instances, which are controlled by the Administration Server for the domain, are called Managed Servers. The configuration for all the servers in the domain is stored in the configuration repository, the config.xml file, which resides on the machine hosting the Administration Server.

Upon installing and configuring Oracle BI 12c, the domain bi is established within the WebLogic Server. This domain is the recommended name for each Oracle BI 12c implementation and should not be modified.

The domain path for the bi domain may appear as ORACLE_HOME/user_projects/domains/bi .

This directory for the bi domain is also referred to as the DOMAIN_HOME or BI_DOMAIN folder.

WebLogic Administration Server

The WebLogic Server is an enterprise software suite that manages a myriad of application server components, mainly focusing on Java technology. It is also comprised of many ancillary components, which enable the software to scale well, and also make it a good choice for distributed environments and high-availability. Clearly, it is good enough to be at the core of Oracle Fusion Middleware. One of the most crucial components of WebLogic Server is WebLogic Administration Server. When installing the WebLogic Server software, the Administration Server is automatically installed with it. It is the Administration Server that not only controls all subsequent WebLogic Server instances, called Managed Servers, but also controls such aspects as authentication-provider security (for example, LDAP) and other application-server-related configurations.

WebLogic Server installs on the operating system and ultimately runs as a service on that machine. The WebLogic Server can be managed in several ways. The two main methods are via the Graphical User Interface (GUI) web application called WebLogic Administration Console, or via a command line using the WebLogic Scripting Tool (WLST). You access the Administration Console from any networked machine using a web-based client (that is, a web browser) that can communicate with the Administration Server through the network and/or firewall.

The WebLogic Administration Server and the WebLogic Server are basically synonymous. If the WebLogic Server is not running, the WebLogic Administration Console will be unavailable as well.

WebLogic Managed Server

Web applications, Enterprise Java Beans (EJB), and other resources are deployed onto one or more Managed Servers in a WebLogic Server Domain. A managed server is an instance of a WebLogic Server in a WebLogic Server Domain. Each WebLogic Server Domain has at least one instance, which acts as the Administration Server just discussed. One administration server per domain must exist, but one or more managed servers may exist in the WebLogic Server Domain.

In a production deployment, Oracle BI is deployed into its own managed server. The Oracle BI installer installs two WebLogic server instances, the Admin Server and a managed server, bi_server1. Oracle BI is deployed into the managed server bi_server1, and is configured by default to resolve to port 9502; the Admin Server resolves to port 9500. Historically, this has been port 9704 for the Oracle BI managed server, and port 7001 for the Admin Server.

When administering the WebLogic Server via the Administration Console, the WebLogic Administration Server instance appears in the same list of servers, which also includes any managed servers. As a best practice, the WebLogic Administration Server should be used for configuration and management of the WebLogic Server only, and not contain any additionally deployed applications, EJBs, and so on.

Note

One thing to note is that the Enterprise Manager Fusion Control is actually a JEE application deployed to the Administration Server instance, which is why its web client is accessible under the same port as the Admin Server. It is not necessarily a native application deployment to the core WebLogic Server, but gets deployed and configured during the Oracle BI installation and configuration process automatically. In the deployments page within the Administration Console, you will find a deployment namedem.

WebLogic Node Manager

The general idea behind Node Manager is that it takes on somewhat of a middle-man role. That is to say, the Node Manager provides a communication tunnel between the WebLogic Administration Server and any Managed Servers configured within the WebLogic Domain. When the WebLogic Server environment is contained on a single physical server, it may be difficult to recognize the need for a Node Manager. It is very necessary and, as part of any of your ultimate start-up and shutdown scripts for Oracle BI, the Node Manager lifecycle management will have to be a part of that process. Node Manager's real power comes into play when Oracle BI is scaled out horizontally on one or more physical servers. Each scaled-out deployment of WebLogic Server will contain a Node Manager.

If the Node Manager is not running on the server on which the Managed Server is deployed, then the core Administration Server will not be able to issue start or stop commands to that server. As such, if the Node Manager is down, communication with the overall cluster will be affected. The following figure shows how machines A, B, and C are physically separated, each containing a Node Manager. You can see that the Administration Server communicates to the Node Manager, and not the Managed Server, directly: