Oracle Internet Directory Oracle Application Server Tips by Burleson Consulting

The Oracle Internet Directory (OID) is a Lightweight Directory Access Protocol (LDAP) directory service that provides centralized storage of information about users, applications, and resources in your enterprise. Coupled with SSO, OID allows end-users to sign-on one time and use their pre-defined OID credential (set-up by the DBA).  This credential defines those components of Oracle9iAS with which the end-user is allowed to interface.

Because it is LDAP-compliant, OID can be viewed as a simple lookup mechanism for web services.  For example, LDAP entries can be used instead of entries in the traditional tnsnames.ora file, thereby allowing connectivity for clients anywhere on your network.  This techniques has replaced the obsolete Oracle*Names tool as a method for defining services for Oracle.

In sum, OID is an easy-to-configure tool for defining end-user access with Oracle9iAS.  Because OID is tightly-coupled with SSO and Oracle advanced security, OID is a critical component is Oracle security management.

Management of OID is made quite simple with a GUI dubbed Oracle Directory Manager (ODM).  While we will be discussing ODM in great detail in Chapter 12, Oracle9iAS Security, for now you should know that ODM is a tool for the Oracle9iAS administrator to manage data access rules.

Metadata Repository (infrastructure)

The metadata repository is a critical component of Oracle9iAS because it allows for a common management interface between multiple instances of Oracle9iAS and the other components.  The metadata repository is commonly referred to as the infrastructure, and this is a critical common component to all Oracle9iAS farms and all Oracle9iAS components that share a common definition.  We will discuss the infrastructure in great detail in Chapter 3, Oracle9iAS Infrastructure.

Oracle Management Server (OMS)

The OMS allows the administrator to include the Application Server in centrally managed configuration using Oracle Enterprise Manager (a separate product).  OMS is a component of the Oracle Enterprise Manager (OEM) Console, and the OMS processes enable the management of the Oracle9iAS instances, databases, and other Oracle9iAS components. The foremost feature of OMS is its ability to store OEM data inside the metadata repository infrastructure.  This storage ability of OMS allows Oracle9iAS administrators to share server configuration information, scheduled Oracle9iAS events and jobs, and share notifications for Oracle9iAS failures.  To start OMS you use the emctl command and issue emctl start oms command to start the webservers and OMS processes.

Because OMS is the ?glue? that ties all of the Oracle9iAS components together, we will be visiting OMS functionality throughout this text.  OMS provides the important functions of user administration and manages the flow of information between the OEM console and all managed nodes.  OEM allows for any server to become a managed node by installing an Oracle intelligent agent (OIA), thereby making it accessible with the central administrative GUI.  An OIA is a daemon process that serves to interface with the database and operating system on each server within each Oracle9iAS farm.  The intelligent agent performs localized execution of tasks as directed by the OMS, and for Oracle servers, the OIA performs time-based database monitoring.  The concept of managed nodes allows ODM to become very powerful, allowing the Oracle9iAS DBA to quickly apply configuration changes to many server components.

Oracle9iAS TopLink

Oracle9iAS TopLink is an important component for Java developers because it provides a mechanism for making Java objects persistent across sessions.  In object-oriented languages such as Java, C# or C++, objects can be instantiated and destroyed according to the needs of the program.

The problem is that OO languages like Java create objects in the RAM heap, and upon termination of the program, all of the programs objects are destroyed.  Oracle9iAS TopLink is a persistence framework that enables object persistence by supplying routines that can be invoked to store Java objects in relational database tables (in any relational database that supports JDBC).  In addition, Oracle9iAS TopLink provides a GUI tool, the Mapping Workbench, that greatly simplifies the task of mapping Java objects and their attributes to database tables.  TopLink also provides powerful features like a query framework, object-level transaction support, relationship mappings, object caching, and much more.  Prior to TopLink, the programmer would have to write custom JDBC code to store and retrieve the Java object?s attributes to/from a relational table. This is extremely time-consuming and error prone plus difficult to change. TopLink is built on top of JDBC but does not require developers to use JDBC (or even SQL!).  Oracle9iAS TopLink supports all J2EE compliant application servers, and can be used to store object data from standard Java objects, as well as entity beans. Please refer to the Oracle9iAS TopLink documentation for more information.

Next, let?s introduce the main topic of this text, the administration and management of Oracle9iAS.

This is an excerpt from "Oracle 10g Application Server Administration Handbook" by Don Burleson and John Garmany.