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Oracle Application Server 10g Administration - Oracle
Get an overview of the Oracle Application Server 10g architecture, its functional components, the administrative tools for application development, and examples of commands that are used to perform frequent Application Server 10g administrative functions. This chapter is from the book, Oracle Application Server 10g Administration Handbook, by John Garmany and Donald K. Burleson (McGraw-Hill/Osborne, ISBN: 0072229586, 2004).
Unlike an Oracle Database, which has only a few administrative interfaces (OEM, SQL*Plus), Application Server 10g has many administrative utilities. To make matters even more challenging, these administrative tools are often tightly coupled, as in the case of the Application Server 10g Web Cache administration pages and the Oracle HTTP Server administration pages. Both of these administrative interfaces are separate, yet they are closely intertwined in the architecture.
Application Server 10g provides two methods for administration, the command-line interface and Oracle Enterprise Manager. This book will show both methods, and the choice of Application Server 10g administration methods is largely up to the individual.
We will start with a review of each administrative component and then look at using OEM and the command-line interfaces within each component.
Administrative Component Overview
As an Application Server 10g administrator, it is your job to become intimate with all of the management components. Of course, your shop may not have some of the optional components, such as Single Sign-On, but it is imperative that you understand the administrative components and how they fit together. This section will review the general administration tools, Web Cache administration tools, and application layer administration tools.
General Administration Components
Here are the main administrative interfaces for the Application Server 10g Infrastructure:
LDAP Server (OID) -- This is the Oracle Internet Directory (OID) component of Application Server 10g. The LDAP server is the foundation of the automated provisioning methodology, and administrators must manage the LDAP repository (the directory) to maintain user-access privileges.
Single Sign-On (SSO) -- The SSO component provides for centralized management among all of the Application Server 10g components. Large shops may have dozens of components, and SSO allows for easy password management and access control.
Metadata repository (isadb) -- The isadb is an Oracle database that stores configuration information and metadata. This includes data used by LDAP, OMS, and SSO.
Mod_osso module -- This provides communication between the SSO-enabled login server and the Oracle HTTP Server (OHS) listener. The mod_osso module is controlled by editing the mod_osso.conf file.
Web Administration Components
From the top down, the web server component (Web Cache and OHS) is one of the most important components of Application Server 10g, and one where tuning is vital. For details on Application Server 10g Web Cache and Oracle HTTP Servers, see Chapter 10.
Oracle HTTP Server (OHS) -- This is the HTTP listener software that intercepts incoming requests and routs them to the appropriate Application Server 10g component. Upon completion of the transaction, the OHS sends the completed HTML or XML back to the originating IP address.
Web Cache -- This component is associated with an OMS instance and server to provide RAM caching for images (GIFs and JPEGs), as well as page content. The Web Cache and the OHS are closely coupled, and tuning the Web Cache is addressed in Chapter 10.
Application Management Components
Moving down the Application Server 10g hierarchy, you next see the administrative tools for application development, primarily for Java applications. Administrators must use these interfaces to ensure optimal configuration of their systems.
J2EE server (OC4J) -- This component allows you to deploy and manage Java-based applications. Administrators must configure the J2EE server to ensure proper communications between OC4J and other Application Server 10gcomponents.
Oracle Process Manager and Notification (OPMN) -- OC4J is started and managed with OPMN, which is also responsible for monitoring all Application Server 10gprocesses and propagating configuration changes across clusters.
Distributed Configuration Manager (DCM) -- DCM is a handy command-line utility that can be used instead of the GUI for starting and stopping Application Server 10gservices.
This chapter is from Oracle Application Server 10g Administration Handbook, by Garmany and Burleson. (McGraw-Hill/Osborne, 2004, ISBN: 0072229586). Check it out at your favorite bookstore today. Buy this book now.