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Oracle® HTTP Server Administrator's Guide
10g Release 2 (10.1.2)
B14007-03
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C Using Oracle Application Server Containers for J2EE Plug-in

This appendix explains how the Oracle Application Server Containers for J2EE Plug-in (OC4J Plug-in) enables you to use third party HTTP listeners to access servlets running in OC4J J2EE within Oracle Application Server. OC4J Plug-in works with Sun ONE Web Server for UNIX, and Microsoft Internet Information Server (IIS) for Windows.


See Also:

http://www.oracle.com/technology/products/ias/ohs/htdocs/plugincerts.html for complete certification information.

It also contains information about using mod_oc4j in a non-Oracle Apache.

Topics discussed are:

C.1 Overview

OC4J Plug-in is a shared library that can be loaded into IIS, or Sun ONE HTTP listener. It provides functionality to route requests directly from a third party listener to OC4J in the same manner mod_oc4j routes requests from Oracle HTTP Server to OC4J. Thus, requests for OC4J can be directly routed from IIS or Sun ONE to one or more OC4J JVMs using the AJP or AJP over SSL protocol.


Note:

OracleAS Proxy Plug-in and OracleAS SSO Plug-in are certified to work with the entire Oracle Application Server stack, such as Oracle Application Server Portal and Oracle Application Server Wireless. However, OC4J Plug-in is only certified to run customer applications. For example, you cannot route requests from Sun ONE using OC4J Plug-in to an OC4J container where Oracle Application Server Wireless is running.

Figure C-1 illustrates how the OC4J Plug-in routes requests directly from a third party listener to OC4J.

Figure C-1 OC4J Plug-in for IIS and Sun ONE

Description of Figure C-1  follows
Description of "Figure C-1 OC4J Plug-in for IIS and Sun ONE"

C.2 Downloading OC4J Plug-in

OC4J Plug-in is available on the Oracle Application Server 10g Companion CD, which is included in your Oracle Application Server CD Pack.

C.3 Installing OC4J Plug-in

On the Oracle Application Server 10g Companion CD, the files are located at /plugins/solaris/ for UNIX and /plugins/win32/ for Windows.

Table C-1 contains information about the shared libraries for OC4J Plug-in.

Table C-1 OC4J Plug-in Shared Libraries

Platform File Name Location and Description Instructions

UNIX

opii.so

opii.so is the OC4J plug-in for Sun ONE Web listener. It is located in the /plugins/solaris/sunone directory

To install the plug-in into the listener, place opii.so in a directory to which the listener has read and execute privileges.

Windows

opii.dll

opii.dll is the OC4J plug-in file for the IIS Web listener. It is located in the /plugins/win32/iis directory.

To install the plug-in into the listener, copy opii.dll to a directory the listener can access.

opii_sunone.dll

opii_sunone.dll is the OC4J plug-in for SUN ONE Web listener. It is located in the /plugins/win32/sunone directory

To install the plug-in into the listener, copy opii_sunone.dll to a directory the listener can access.



Note:

In order to use the OracleAS SSO Plug-in or to turn on SSL with the OC4J Plug-in when using the plug-ins within IIS 6.0 on Microsoft Windows 2003, the permissions on the .dll files in the %ORACLE_HOME%\bin location must be changed. The .dll files must have execution permissions for the user NETWORK SERVICE added.

Do not complete this operation during normal installation.

Because IIS 6.0 is run as the user NETWORK SYSTEM, the plug-ins will not function correctly unless the necessary permissions are granted.


C.4 Configuring OC4J Plug-in on Sun ONE

Place the opii.so file in a directory such as /sunone/opii.so, where it is readable by the Sun ONE listener. The following examples assume that Sun ONE is installed in a directory called /sunone, and that the instance being configured exists under /sunone/https-mymachine.

  1. Add the following lines at the end of /sunone/https-mymachine/magnus.conf:

    Init fn="load-modules" shlib="/sunone/opii.so" funcs=opii_init,opii_objecttype,opii_service,opii_child_init
    
    Init fn="opii_init" log_file="/sunone/https-mymachine/logs/opii.log"
      log_level=error server_defs="/sunone/https-machine/config/opii.conf"
    Init fn="opii_child_init" LateInit=yes
    
    

    where, log_file points to a file where OC4J Plug-in messages will be logged and server_defs points to an OC4J configuration file.

  2. Make the following modifications to /sunone/https-mymachine/obj.conf:

    1. Add the following line before any ObjectType line:

      ObjectType fn=opii_objecttype
      
      
    2. Add the following line before all other lines that begin with the word "Service":

      Service type="oracle/opii" fn="opii_service" UseOutStreamSize=8192
      
      

      Note:

      Not all versions of Sun ONE support UseOutputStreamSize. Refer to Sun ONE documentation for details.

  3. If you want to enable the OC4J status page, which is equivalent to the URL /oc4j-service in mod_oc4j for Oracle HTTP Server, then make the following two changes to obj.conf:

    1. Add the following line above the other NameTrans entries inobj.conf:

      NameTrans fn=assign-name from="/oc4j-service" name="opii-status"
      
      
    2. Add the following section at the end of obj.conf:

      <Object name="opii-status">
      
          Service fn="opii_status_service"
    
         </Object>

C.5 Configuring OC4J Plug-in for IIS

Perform the following steps to configure OC4J Plug-in for IIS:

  1. Edit your registry to create a new registry key named HKEY_LOCAL_MACHINE\SOFTWARE\Oracle\OPII

  2. Specify the exact location of your configuration file with the name server_defs, and a value pointing to the location of your configuration file, for example d:\opii\opii.conf.

  3. (Optional) Specify a log_file and log_level:

    1. Add a string value with the name log_file, and the desired location of the log file, for example, d:\opii\plugin.log.

    2. Add a string value with the name log_level, and a value for the desired log level. Valid values are debug, inform, error, and emerg.

    3. If you want to enable the OC4J Plug-in status page, a page equivalent to mod_oc4j /oc4j-service URL, add a string value with the name status_uri and a value like /oc4j-service.

  4. Using the IIS management console, add a new virtual directory to your IIS Web site with the same physical path as that of opii.dll. Name the directory opii and give it execute access.

  5. Using the IIS management console, configure the plugin as an allowed Web Service Extension.

  6. Using the IIS management console, add opii.dll as a filter in your IIS Web site. The name of the filter should be opii and its executable must point to the directory contain opii.dll, for example, d:\opii\opii.dll.

  7. If you want to use dynamic routing, ensure that ORACLE_HOME is set in the system environment or plugin config file using the Oc4jOracleHome directive. Using the IIS management console, set the Identity of the Application Pool containing the plugin to "Local System" so that the plugin can communicate with OPMN.

  8. Restart IIS (stop and then start the IIS server), ensuring that the filter is marked with a green arrow pointing up.


    Note:

    To restart IIS, you must stop all of the IIS services through the control panel, or restart the computer. This is the only way to ensure that the .dll is reloaded. Restarting IIS through the management console is not sufficient.

C.5.1 Configuring Anonymous Access for IIS

Perform the following steps if you want OC4J to perform the authentication:

  1. In the IIS Management GUI, right click the default Web site and select Properties.

  2. Select the Directory Security tab and click the Edit button under Anonymous Access and Authentication Control. Be sure that the Anonymous access is checked and that basic authentication and integrated Windows Authentication are both unchecked.


Note:

If you want IIS to perform authentication and simply pass the user name to OC4J, then do not disable authentication in IIS.

C.6 OC4J Plug-in Configuration File

When you set up the OC4J Plug-in in the third party listener, the configuration file points at a server_defs file, or the OC4J Plug-in configuration file. This file defines the OC4J instances that the OC4J Plug-in communicates with. It has the same syntax as the mod_oc4j file for Oracle HTTP Server. For example, a configuration file that contains only the following line

Oc4jMount /j2ee/* ajp13://localhost:3000

routes any requests to URLs that begin with/j2ee/ to the OC4J instance that has an AJP listener on the localhost interface on port 3000.

All of the Oc4j* directives defined for mod_oc4j also work for OC4J Plug-in. In additional to these directives, the OC4J Plug-in-specific directives Oc4jOracleHome can be used in place of setting the ORACLE_HOME directive in the environment for the third party listener. An ORACLE_HOME value is required if you want to use the dynamic functionality of the OC4J Plug-in.

The dynamic routing functionality of the OC4J Plug-in provides the same Oc4jMount syntax as mod_oc4j for routing to OC4J instances that are managed by OPMN. Accordingly, you can mount OC4J instances or clusters instead of just pointing at the host and port of a single JVM. In order to accomplish this, the OC4J Plug-in must be able to communicate with an ONS daemon on the same machine. If Oracle Application Server is installed on the same machine as the OC4J Plug-in, then this can be accomplished simply by setting either ORACLE_HOME in the environment, or setting the Oc4jOracleHome directive to point to the location of the ORACLE_HOME, and ensuring that the third party listener is running as the same user as Oracle Application Server, or root on UNIX.

If Oracle Application Server is not installed on the same machine, then the standalone ONS daemon must be installed. OC4J Plug-in supports all the mod_oc4j functionality, including AJP over SSL and use of port tunneling.

C.7 Integrating Generic Apache with Oracle Application Server

In Oracle Application Server, 10g Release 2 (10.1.2), you can integrate generic Apache with Oracle Application Server. In doing so, you can route requests from generic Apache to OC4J in the same manner as routing requests using Oracle HTTP Server and mod_oc4j. Generic Apache is Apache version 1.3.xx, and not Apache 2.x.

Using Oracle Notification Service (ONS), the communication method utilized between mod_oc4j and OC4J, you can load mod_oc4j into a generic Apache instance and use it in a static routing configuration without requiring any other Oracle infrastructure. In combination with mod_onsint and ONS, mod_oc4j can utilize the same dynamic configuration and failover options that are available when using Oracle HTTP Server.


See Also:

"mod_onsint"

This section discusses the following topics:

C.7.1 Integration Requirements

mod_oc4j and mod_onsint require the following open source software packages to be included in generic Apache builds that will be integrated with Oracle Application Server:

  • Enhanced API (EAPI) provided as part of mod_ssl. EAPI provides a context mechanism that is used extensively by mod_onsint and mod_oc4j to share information and function callbacks between modules without introducing link time dependencies. EAPI is provided by configuring Apache with mod_ssl.


    Note:

    mod_ssl does not need to be loaded at runtime as it is the integration of EAPI provided by mod_ssl that is important.

  • (UNIX only) mm shared memory library. The mm library is used on UNIX platforms to share routing information between all of the child processes that make up an Apache instance on UNIX. This library is not necessary on Windows platforms since the Apache architecture on Windows uses a single multi-threaded process instead of many single-threaded processes.


    Note:

    mod_oc4j is supported in Apache versions 1.3.x only. It is not supported in Apache 2.0.x versions.

C.7.2 Generic Apache Files

Four libraries need to be accessible by the generic Apache instance that is going to be integrated with Oracle Application Server. If mod_oc4j is used in a static configuration and mod_onsint is not used, then you need only two libraries.

On UNIX, the four files and their locations within an ORACLE_HOME are:

$ORACLE_HOME/Apache/Apache/libexec/mod_oc4j.so
$ORACLE_HOME/Apache/Apache/libexec/mod_onsint.so
$ORACLE_HOME/opmn/lib/libons.so
$ORACLE_HOME/lib/libdms2.so

On Windows, the four files and their locations within an ORACLE_HOME are:

%ORACLE_HOME%\Apache\Apache\modules\ApacheModuleOc4j.dll
%ORACLE_HOME%\Apache\Apache\modules\ApacheModuleOnsint.dll
%ORACLE_HOME%\opmn\bin\onsclient.dll
%ORACLE_HOME%\bin\yod.dll


Note:

These files are also available on the Oracle Application Server 10g Companion CD. On the CD, they are located in the /plugins/solaris/ directory for UNIX and /plugin/win32/ directory for Windows.

It is easiest if the binaries for the two modules are copied into the same location as the other modules in the generic Apache installation (libexec on UNIX, and modules on Windows), although this is not a requirement. Full paths can be used if you want to place the binaries elsewhere. The dms and ons libraries do not need to be in any specific location, but they must be in the your LD_LIBRARY_PATH on UNIX, and the PATH on Windows. On UNIX, this is most easily accomplished by editing the apachectl script used to start the generic Apache instance to set the LD_LIBRARY_PATH appropriately. On Windows, this is most easily accomplished by placing the appropriate directory into the System environment variable PATH. However, if more than one generic Apache instance is running on the same machine, then some other mechanism might be needed.

C.7.3 Setting Up a Static Configuration with mod_oc4j

A simple configuration can be constructed using generic Apache and only mod_oc4j.

In this configuration, the host and port of all OC4J instances must be statically configured. There is no automatic registration of new JVMs, nor are failed JVMs ever removed from the routing table used by mod_oc4j. The advantage of this configuration is its simplicity, including the fact that it does not require the availability of other Oracle Application Server infrastructure components, such as ONS. The following is an example of such a configuration. This configuration loads mod_oc4j and provides routing of all requests starting with /j2ee/ to two different JVMs, both located on the same machine, one at port 3001, and the other at port 3002:

LoadModule oc4j_module libexec/mod_oc4j.so
Oc4jMount /j2ee/* ajp13://localhost:3001,ajp13://localhost:3002

On Windows, change the line used to load mod_oc4j to the following:

LoadModule oc4j_module modules/ApacheOc4jModule.dll

On UNIX, this assumes that the mod_oc4j.so file will be copied into the libexec directory within the Apache installation. On Windows, it means that the ApacheOc4jModule.dll file will be copied to the modules directory within the Apache installation.

C.7.4 Setting Up a Dynamic Configuration with mod_oc4j and mod_onsint

In order to provide full mod_oc4j functionality including dynamic detection of new JVMs and Oracle Application Server installations, mod_oc4j must be combined with mod_onsint.

In order to utilize mod_onsint and mod_oc4j, ORACLE_HOME must be set to point to an Oracle Application Server instance where OPMN is running. On UNIX, this can be accomplished by adding the setting of ORACLE_HOME to the apachectl script used to start the generic Apache instance. On Windows, this is most easily accomplished by setting ORACLE_HOME as a System environment variable.

The following configuration shows how to load the modules and mount /j2ee to the OC4J instance, myinstance, running within the Oracle Application Server cluster, mycluster.

LoadModule onsint_module libexec/mod_onsint.so
LoadModule oc4j_module libexec/mod_oc4j.so
Oc4jMount /j2ee/* cluster://mycluster:myinstance

Any allowable Oc4jMount syntax available from within Oracle HTTP Server is available when used with generic Apache. This configuration supports all of the same routing and availability features that mod_oc4j offers when running within Oracle HTTP Server, including dynamic discovery of new OC4J processes and instances as they are added and failover of both stateless and session based requests.

C.7.5 Integrating with Oracle Process Manager and Notification Server

Oracle Process Manager and Notification Server (OPMN) can be configured to provide process management, such as starting, stopping, and restart capability for a generic Apache installation. To do this, the Apache instance must have mod_onsint configured. It should have the standard Apache directory layout, that is, the directory structure created by doing a standard Apache 1.3 installation.


Note:

When generic Apache is started using OPMN, you have to set OpmnHostPort directive in httpd.conf or Apache will fail to start. For more information on OpmnHostPort, refer to "mod_onsint"

To configure OPMN to manage this Apache instance, the following changes must be made to opmn.xml:

In the module section add the GENERIC_APACHE module-id to the configuration for libopmnohs, such as:

<module path="$ORACLE_HOME/opmn/lib/libopmnohs"> 
  <module-id id="OHS"/> 
  <module-id id="GENERIC_APACHE"/> 
</module> 

In the HTTP_Server section, you must set the module to GENERIC_APACHE and set an apache-home, such as:

</ias-component>
  <ias-component id="HTTP_Server"> 
    <process-type id="HTTP_Server" module-id="GENERIC_APACHE"> 
      <module-data> 
        <category id="start-parameters"> 
          <data id="apache-home" value="/private/my/path/to/APACHE"/> 
        </category> 
      </module-data> 
    <process-set id="HTTP_Server" numprocs="1"/> 
  </process-type> 
</ias-component>

You can configure either an Oracle HTTP Server instance or a generic Apache instance into any opmn.xml. Configuring both in the same opmn.xml is currently not supported.


See Also:

"opmn.xml"