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Understanding Oracle Fusion Middleware Concepts
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2 Understanding Key Concepts

This chapter provides information about key Oracle Fusion Middleware concepts, such as domains, Administration Server, Managed Servers, Java components, system components, as well as the directory structure of an Oracle Fusion Middleware installation.

2.1 What is an Oracle WebLogic Server Domain?

An Oracle WebLogic Server domain is a logically related group of Java components. A domain includes a special WebLogic Server instance called the Administration Server, which is the central point from which you configure and manage all resources in the domain. Usually, you configure a domain to include additional WebLogic Server instances called Managed Servers. You deploy Java components, such as Web applications, EJBs, and Web services, and other resources, to the Managed Servers and use the Administration Server for configuration and management purposes only.

An Oracle WebLogic Server domain that was created using the Oracle Fusion Middleware Infrastructure distribution can also include system components, such as Oracle HTTP Server.

Managed Servers in a domain can be grouped together into a cluster.

The directory structure of a domain is separate from the directory structure of the WebLogic Server home. It can reside anywhere; it need not be within the Oracle home directory. The top-level directory of a domain is referred to as the domain home.

Figure 2-1 shows an extended domain with an Administration Server, and two Managed Servers in a cluster. It also shows a database, which holds the metadata for Oracle Fusion Middleware

Figure 2-1 Oracle WebLogic Server Domain

Description of Figure 2-1 follows
Description of "Figure 2-1 Oracle WebLogic Server Domain"

See Also:

Understanding Domain Configuration for Oracle WebLogic Server for more information about domain configuration

A domain can also contain system components, such as Oracle HTTP Server.

The following topics describe entities in the domain:

2.1.1 What Is the Administration Server?

The Administration Server operates as the central control entity for the configuration of the entire domain. It maintains the domain's configuration documents and distributes changes in the configuration documents to Managed Servers. The Administration Server serves as a central location from which to manage and monitor all resources in a domain.

Each domain must have one server instance that acts as the Administration Server.

To interact with the Administration Server, you can use Fusion Middleware Control, the Oracle WebLogic Server Administration Console, Oracle WebLogic Scripting Tool (WLST), or create your own JMX client.

Oracle WebLogic Server Administration Console and Fusion Middleware Control run in the Administration Server. Oracle WebLogic Server Administration Console is the Web-based administration console used to manage the resources in an Oracle WebLogic Server domain, including the Administration Server and Managed Servers. Fusion Middleware Control is a Web-based administration console used to manage Oracle Fusion Middleware, including components such as Oracle WebLogic Server, Oracle Coherence, and Oracle HTTP Server.

See Also:

2.1.2 Understanding Managed Servers and Managed Server Clusters

Managed Servers host business applications, application components, Web services, and their associated resources. To optimize performance, Managed Servers maintain a read-only copy of the domain's configuration document. When a Managed Server starts, it connects to the domain's Administration Server to synchronize its configuration document with the document that the Administration Server maintains.

When you create a domain, you create it using a particular domain template. That template supports a particular component or group of components, such as the Oracle SOA Suite. The Managed Servers in the domain are created specifically to host those particular Oracle Fusion Middleware components.

Oracle Fusion Middleware Java components (such as Oracle Coherence), as well as customer-developed applications, are deployed to Managed Servers in the domain.

If you want to add other components to a domain that was created using a template that supports another component, you can extend the domain by creating additional Managed Servers in the domain, using a domain template for the component that you want to add. See "Extending a Domain to Support Additional Components" in Administering Oracle Fusion Middleware for more information.

For production environments that require increased application performance, throughput, or high availability, you can configure two or more Managed Servers to operate as a cluster. A cluster is a collection of multiple WebLogic Server instances running simultaneously and working together to provide increased scalability and reliability. In a cluster, most resources and services are deployed identically to each Managed Server (as opposed to a single Managed Server), enabling failover and load balancing. A single domain can contain multiple Oracle WebLogic Server clusters, as well as multiple Managed Servers that are not configured as clusters. The key difference between clustered and nonclustered Managed Servers is support for failover and load balancing. These features are available only in a cluster of Managed Servers.

See Also:

"Understanding WebLogic Server Clustering" in Administering Clusters for Oracle WebLogic Server

2.1.3 What Is a Java Component?

A Java component is an Oracle Fusion Middleware component that is deployed as one or more Java EE applications and a set of resources. Java components are deployed to an Oracle WebLogic Server domain as part of a domain template. Oracle WebLogic Server and Oracle Coherence are examples of Java components.

2.1.4 What Is a System Component?

A system component is a manageable process that is not deployed in a Java application container. Oracle HTTP Server is an example of a system component. System components can be deployed in a WebLogic Server domain or in a standalone domain and managed by the Weblogic Management Framework. See Section 2.4 for information about the Weblogic Management Framework.

2.1.5 What Is Node Manager?

Node Manager is a Java utility that runs as a separate process from Oracle WebLogic Server and allows you to perform common operations for a Managed Server, regardless of its location with respect to its Administration Server, and for system components. You can perform those operations from a remote location. While use of Node Manager is optional in a WebLogic domain, it provides valuable benefits if your Oracle WebLogic Server environment hosts applications with high-availability requirements. It is not optional in a standalone domain.

If you run Node Manager on a computer that hosts Managed Servers, you can start and stop the Managed Servers remotely using the Administration Console, Fusion Middleware Control, or the command line. Node Manager can also automatically restart a Managed Server after an unexpected failure.

You can configure the scope of Node Manager:

  • Per domain

    With a per-domain Node Manager, the Node Manager is associated with a domain and is configured to control all servers for the domain on a machine. (A per-domain Node Manager is a Java-based Node Manager.)

    This is the default when you configure Node Manager with the Configuration Wizard.

  • Per Machine

    With a per-machine Node Manager, the Node Manager process is not associated with a specific WebLogic Server domain but with a machine. You can use the same Node Manager process to control server instances in any WebLogic Server domain, as long as the server instances reside on the same machine as the Node Manager process. A per-machine Node Manager must run on each computer that hosts WebLogic Server instances—whether Administration Server or Managed Server—that you want to control with Node Manager.

2.2 What Is a Standalone Domain?

A standalone domain is a container for system components, such as Oracle HTTP Server. It has a directory structure similar to an Oracle WebLogic Server domain, but it does not contain an Administration Server or Managed Servers. It can contain one or more instances of system components of the same type, such as Oracle HTTP Server, or a mix of system component types.

The WebLogic Management Framework provides tools for managing standalone domains. See Section 2.4 for more information about the WebLogic Management Framework.

Generally, you use a standalone domain when you do not want your Oracle HTTP Server implementation to front an Oracle WebLogic Server domain and do not need the management functionality provided by Fusion Middleware Control.

Figure 2-4 shows a standalone domain with Oracle HTTP Server installed.

Figure 2-2 Standalone Domain

Description of Figure 2-2 follows
Description of "Figure 2-2 Standalone Domain"

2.3 What are the Key Oracle Fusion Middleware Directories?

Figure 2-3 shows the high-level directory structure after installing and configuring Oracle Fusion Middleware with Oracle WebLogic Server and Oracle JRF.

Figure 2-3 Directory Structure of a Oracle WebLogic Server Domain

Description of Figure 2-3 follows
Description of "Figure 2-3 Directory Structure of a Oracle WebLogic Server Domain"

For a diagram of the directory structure when Oracle HTTP Server is installed in a WebLogic domain, see "Understanding the Oracle HTTP Server Directory Structure in a WebLogic Server Domain" in Installing and Configuring Oracle HTTP Server.

Table 2-1 describes the key Oracle Fusion Middleware directories and the variables that are used when referring to those directories in an Oracle Fusion Middleware installation. When you see these variables in an example or procedure, replace the variable with the full path to the corresponding directory path in your enterprise topology.

Note:

The directory paths provided in the examples below assume that Oracle Universal Installer's default directory names were used.

Table 2-1 Directories in a Oracle Fusion Middleware Installation

Directory Name Variable Description Directory Path

Oracle home

ORACLE_HOME

The Oracle home that is created for all the Oracle Fusion Middleware products on a host computer. This read-only directory contains binary and library files, the Oracle common directory and the individual product directories for each Oracle Fusion Middleware product you install.

/install_location/Oracle_Home

Oracle Common home

ORACLE_COMMON

The directory that contains the binary and library files that are common to all the Oracle Fusion Middleware products and features installed in the Oracle home.

In addition, the Oracle Common directory includes the files required for common tools, such as Oracle Enterprise Manager Fusion Middleware Control, WLST, the Configuration Wizard, upgrade tools, and Oracle JRF

There is only one Oracle Common directory within each Oracle home.

/install_location/Oracle_Home/oracle_common

product directory

PROD_DIR

The directory within the Oracle home, which contains the binary files associated with a logical product or feature set. The name of each product directory within the Oracle home is predefined by the installer and cannot be changed.

/install_location/Oracle_Home/Prod_Dir

Oracle WebLogic Server home

WL_HOME

The specific product directory for the WebLogic Server binary files.

/install_location/Oracle_Home/wlserver

Fusion Middleware Control

EM_DIR

The Oracle Enterprise Manager Fusion Middleware Control Console directory within an Oracle Fusion Middleware Oracle home. This directory contains the binary and library files required to run Fusion Middleware Control.

/install_location/Oracle_Home/em

Domain home

DOMAIN_HOME

The location in which the domain information and configuration artifacts are stored.

For information, about a Oracle WebLogic Server domain, see Section 2.1.

For information, about a standalone domain, see Section 2.1.

/install_location/oracle/domains/base_domain

Application home

APPLICATION_HOME

The directory where the applications related to the domains you configure will be created. Oracle recommended that this location reside outside of the Oracle home directory; in the event that you need to upgrade or patch your software, the files inside the Oracle home would be affected.

install_location/oracle/applications


Figure 2-4 shows the directory structure when you have installed a system component, such as Oracle HTTP Server, in a standalone domain.

Figure 2-4 Directory Structure of a Standalone Domain

Description of Figure 2-4 follows
Description of "Figure 2-4 Directory Structure of a Standalone Domain"

The directories are described in Table 2-1.

2.4 What is the WebLogic Management Framework?

Oracle Fusion Middleware provides the WebLogic Management Framework, which provides heterogeneous management capabilities for Oracle Fusion Middleware products that require basic administrative capabilities. Its capabilities include start, stop, configuration settings and other such basic product lifecycle operations through a common command line, API and user interface. WebLogic Management Framework is comprised of specific WebLogic Server and Coherence features.

The WebLogic Management Framework manages both WebLogic Server domains, which can contain Java components and system components, and standalone domains, which contain system components. However, not all functionality is provided for standalone domains, as shown in the following table:

Functionality WebLogic Server Domain Standalone Domain More information

Node Manager

Yes

Yes

Section 2.1.5

WebLogic Scripting Tool

Yes

Yes

Section 4.2.3

Configuration Wizard

Yes

Yes

Creating Domains Using the Configuration Wizard

pack and unpack utilities

Yes

Yes

Creating Templates and Domains Using the Pack and Unpack Commands

WebLogic Server JMX and MBean Infrastructure

Yes

No

Developing Custom Management Utilities Using JMX for Oracle WebLogic Server

WebLogic Server RESTful Management Services

Yes

No

Administering Oracle WebLogic Server with RESTful Management Services

Weblogic.deployer

Yes

No

"weblogic.Deployer Command-Line Reference" in Deploying Applications to Oracle WebLogic Server

Coherence Caching for WebLogic Management Framework

Yes

No

Managing Oracle Coherence

Administration Console

Yes

No

Section 4.2.2

Fusion Middleware Control

Yes

No

Section 4.2.1


2.5 What Is the Metadata Repository?

The metadata repository contains metadata for Oracle Fusion Middleware components, such as Oracle Application Development Framework. It can also contain metadata about the configuration of Oracle Fusion Middleware and metadata for enterprise applications.

A metadata repository can be database-based or file-based. If it is database-based, repository can be installed into an existing database using the Repository Creation Utility (RCU). With RCU, you can create schemas for Oracle Fusion Middleware components.

For more information about database-based metadata repositories, see Creating Schemas with the Repository Creation Utility.

A particular type of repository, the MDS Repository, contains metadata for most Oracle Fusion Middleware components, such as Oracle Application Development Framework, and for certain types of applications. For more information about the MDS Repository, see "Managing the MDS Repository" in Administering Oracle Fusion Middleware.