In this post I will explain following key concepts in Oracle Fusion Middleware 11g
- Oracle Fusion Middleware Component Types
- Oracle WebLogic Server Domain
- Oracle Instance
- Oracle Fusion Middleware Home Directories & Structure
Oracle Fusion Middleware Component Types
Oracle Fusion Middleware provides two types of components:
- Java Components
- System Components
Java Component
A Java component, which 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. Examples of Java components are the Oracle SOA Suite and Oracle WebCenter components.
System Component
A system component, which is a manageable process that is not deployed as a Java application. Instead, a system component is managed by the Oracle Process Manager and Notification (OPMN). The system components are:
- Oracle HTTP Server
- Oracle Web Cache
- Oracle Internet Directory
- Oracle Virtual Directory
- Oracle Forms Services
- Oracle Reports
- Oracle Business Intelligence Discoverer
- Oracle Business Intelligence
- A Java component and a system component are peers.
A Java component and a system component are peers.
Oracle WebLogic Server Domain
What is Oracle WebLogic Server domain ?
An Oracle WebLogic Server domain is a logically related group of Java components. A domain includes a special Oracle WebLogic Server instance called the Administration Server, which is the central point from at which configuration and management of all resources in the domain occur. Usually, you configure an additional domain to include additional Oracle WebLogic Server instances called Managed Servers. You can deploy Java components, such as Web applications, Enterprise Java Beans (EJB), and Web services, and other resources to the Managed Servers and uses the Administration Server for configuration and management purposes only.
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 Oracle WebLogic Server home. It can reside anywhere; it need not be within the Middleware home directory.
A domain is a peer of an Oracle instance. Both contain specific configurations outside of their Oracle homes.
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 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 the Oracle WebLogic Server Administration Console, Oracle WebLogic Scripting Tool (WLST), or create your own Java Management Extension (JMX) client. In addition, you can use Oracle Enterprise Manager Fusion Middleware Control (Fusion Middleware Control Console) for some tasks.
Oracle WebLogic Server Administration Console and Fusion Middleware Control run in the Administration Server.
What is the Managed Servers ?
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 up, 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. The domain template contains all of the information you would like to include in your domain configuration. The template can then be used for additional installations. 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 SOA Suite, Oracle WebCenter, and some Oracle Identity Management components), as well as customer-developed applications, are deployed to Managed Servers in the domain.
Managed servers are Java Virtual Machine (JVM) processes.
What is the Managed Server Clusters ?
A cluster is a collection of multiple Oracle WebLogic Server 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 non-clustered Managed Servers is support for failover and load balancing. These features are available only in a cluster of Managed Servers.
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. While use of Node Manager is optional, it provides valuable benefits if your Oracle WebLogic Server environment hosts applications with high-availability requirements.
Oracle Instance
An Oracle instance contains one or more system components, such as Oracle Web Cache, Oracle HTTP Server, or Oracle Internet Directory. The system components in an Oracle instance must reside on the same computer. An Oracle instance directory contains updateble files, such as configuration files, log files, and temporary files.
An Oracle instance is a peer of an Oracle WebLogic Server domain. Both contain specific configurations outside of their Oracle homes.
The directory structure of an Oracle instance is separate from the directory structure of the Oracle home. It can reside anywhere; it need not be within the Middleware home directory.
Oracle Fusion Middleware Home Directories & Structure
What is a Middleware Home?
A Middleware home is a container for the Oracle WebLogic Server home, and, optionally, one Oracle Common home and one or more Oracle homes.
A Middleware home can reside on a local file system or on a remote shared disk that is accessible through NFS.
What is a WebLogic Server Home?
A WebLogic Server home contains installed files necessary to host a WebLogic Server. The WebLogic Server home directory is a peer of Oracle home directories and resides within the directory structure of the Middleware home.
What is an Oracle Home?
An Oracle home contains installed files necessary to host a specific component or software suite. For example, the SOA Oracle home contains a directory that contains binary and library files for Oracle SOA Suite.
An Oracle home resides within the directory structure of the Middleware home. Each Oracle home can be associated with multiple Oracle instances or Oracle WebLogic Server domains. There can be multiple Oracle homes within each Middleware home.
What is the Oracle Common Home?
The Oracle Common home contains the binary and library files required for the Oracle Enterprise Manager Fusion Middleware Control and Java Required Files (JRF). There can be only one Oracle Common home within each Middleware home.
Oracle Fusion Middleware Directory Structure
