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Oracle HTTP Server Overview

This chapter describes the Oracle HTTP Server, highlighting the differences between the Oracle distribution and the open source Apache product on which it is based. It also explains how to start, stop and restart the server.

Topics discussed are:

• Oracle HTTP Server Features

• Oracle HTTP Server Components

• Oracle HTTP Server Support

• Oracle HTTP Server Management

• Starting, Stopping, and Restarting Oracle HTTP Server

Documentation from the Apache Software Foundation is referenced when applicable.

Note: Readers using this guide in PDF or hard copy formats will be unable to access third-party documentation, which Oracle provides in HTML format only. To access the third-party documentation referenced in this guide, use the HTML version of this guide and click on the hyperlinks.

Oracle HTTP Server Features

Oracle HTTP Server is the Web server component of Oracle Application Server. It is based on the Apache HTTP Server, version 1.3.28. It is a robust, reliable Web server, pre-configured to do the following:

• provide a high availability infrastructure integration with Oracle Process Manager and Notification Server (OPMN), for process management, death detection and failover for OC4J and Oracle HTTP Server processes.

  See Also: Oracle Application Server 10g High Availability Guide

• provide Dynamic Monitoring Services (DMS) metrics that give runtime performance statistics for both Oracle HTTP Server and OC4J processes. As applications run, DMS collects detailed performance statistics. This data allows you to monitor the duration of important request processing phases and status information. With this information, you can locate performance bottlenecks and tune the application server to maximize throughput and minimize response time.

  See Also: Oracle Application Server 10g Performance Guide

• provide a request ID, which enhances request tracking through various components by attaching a request ID to each request. This provides more detailed information, allowing you to see how much time a particular request spends in any component or layer.

• integrate with single sign-on capability through Oracle Application Server Single Sign-On.

  See Also: Oracle Application Server Single Sign-On Administrator's Guide

• enable securing of transactions with Secure Sockets Layer (SSL) technology.

  See Also: Oracle Application Server 10g Security Guide Chapter 10, "Managing Security"

• execute Perl scripts in the same process as the Oracle HTTP Server, or as CGI script.

• access database stored procedures with a PL/SQL engine.

  See Also: Oracle Application Server 10g mod_plsql User's Guide

• enable scripting of HTML pages with PL/SQL code.

• support legacy use of Apache JServ, including a process management and death detection module (mod_oprocmgr).

  See Also: "mod_oprocmgr"

• provide proxy plug-in for non-Oracle HTTP listeners.

  See Also: Appendix A, "Using Oracle Application Server Proxy Plug-in"

Oracle HTTP Server Components

Oracle HTTP Server consists of several components that run within the same process. These components provide the extensive list of features that Oracle HTTP Server offers when handling client requests. Following are the major components:

• HTTP Listener: Oracle HTTP Server is based on an Apache HTTP listener to serve client requests. An HTTP server listener handles incoming requests and routes them to the appropriate processing utility.

• Modules (mods): Many of the standard Apache modules are included with Oracle HTTP Server. Oracle also includes several internal modules that are specific to Oracle Application Server components.

  See Also: "Oracle HTTP Server Modules" for a complete list of modules shipped with Oracle HTTP Server.

• Perl Interpreter: A persistent Perl runtime environment embedded in Oracle HTTP Server through mod_perl.

Figure 1-1 shows the path of various requests through Oracle HTTP Server components, where a client machine connects to Oracle Application Server Web Cache, which in turn connects to Oracle HTTP Server. Oracle HTTP Server, using various modules, connects to the database through OC4J, FastCGI, or the Perl interpreter.

Figure 1-1 Oracle HTTP Server Request Flow

Text description of the illustration httparch.gif

See Also: Oracle Application Server 10g Concepts for more information regarding Oracle Application Server components, and how they relate to each other.

Oracle HTTP Server Modules

Table 1-1 identifies the modules shipped with Oracle HTTP Server. Modules extend the basic functionality of the Web server, and support integration between Oracle HTTP Server and other Oracle Application Server components. Note that the list differs from the Apache open source distribution (given the inclusion of Oracle modules), and that not all modules are supported by Oracle.

Table 1-1 Oracle HTTP Server Modules  

Module	Oracle Support	Notes
mod_access	Yes
mod_actions	Yes
mod_alias	Yes
mod_asis	No
mod_auth	Yes
mod_auth_anon	Yes
mod_auth_db	No	Disabled. Not shipped by Oracle.
mod_auth_dbm	No
mod_auth_digest	No	Disabled. Experimental MD5 authentication; not shipped by Oracle.
mod_autoindex	Yes
mod_cern_meta	No
mod_certheaders	Yes
mod_cgi	Yes
mod_define	Yes	UNIX systems only.
mod_digest	Yes
mod_dir	Yes
mod_dms	Yes	Oracle module.
mod_env	Yes
mod_example	No
mod_expires	Yes
mod_fastcgi	Yes
mod_headers	Yes
mod_imap	No
mod_include	Yes
mod_info	Yes
mod_isapi	No	Windows systems only. Not shipped by Oracle
mod_jserv	Yes	Disabled by default in Oracle configuration.
mod_log_agent	No	Deprecated.
mod_log_config	Yes
mod_log_referer	Yes	Deprecated.
mod_mime	Yes
mod_mime_magic	Yes
mod_mmap_static	No
mod_negotiation	Yes
mod_oc4j	Yes	Oracle module. Recommended servlet container; enabled by default in Oracle configuration.
mod_onsint	Yes	Oracle module.
mod_oprocmgr	Yes	Oracle module.
mod_oradav	Yes	Oracle module.
mod_ossl	Yes	Oracle module.
mod_osso	Yes	Oracle module.
mod_perl	Yes
mod_plsql	Yes	Oracle module.
mod_proxy	Yes
mod_rewrite	Yes
mod_setenvif	Yes
mod_so	Yes
mod_speling	Yes
mod_status	Yes
mod_unique_id	Yes
mod_userdir	Yes
mod_usertrack	Yes
mod_vhost_alias	Yes

Oracle HTTP Server Support

Oracle provides technical support for the following Oracle HTTP Server features and conditions:

• Modules included in the Oracle distribution, except as noted in the table in Table 1-1, "Oracle HTTP Server Modules". Modules from any other source, including the Apache Software Foundation, are not supported by Oracle.

• Problems that can be reproduced within an Apache configuration consisting only of supported Oracle Apache modules.

• Use of the included Perl interpreter within the supported Apache configuration.

Oracle HTTP Server Management

Oracle HTTP Server can be managed using the following two methods:

• Application Server Control

• Oracle Application Server Command-line Tools

Application Server Control

You can manage Oracle HTTP Server using Oracle Enterprise Manager. Oracle Enterprise Manager enables you to manage your server from a Web browser using Oracle Enterprise Manager Application Server Control (Application Server Control).

See Also: Chapter 7, "Application Server Control Management" for information on managing Oracle HTTP Server using Application Server Control. Oracle Application Server 10g Administrator's Guide for detailed information on Oracle Enterprise Manager Application Server Control and other GUI-based management tools.

Oracle Application Server Command-line Tools

You can use also the following command-line tools to manage Oracle HTTP Server:

opmnctl

Provides a command-line utility for Oracle Process Manager and Notification Server (OPMN) for process management. It is located in

• UNIX: ORACLE_HOME/opmn/bin

• Windows: ORACLE_HOME\opmn\bin

  See Also: Oracle Process Manager and Notification Server Administrator's Guide for more information on opmnctl.

dcmctl

Provides a command-line utility for Distributed Configuration Management (DCM) for configuration management and application deployment. It is located in

• UNIX: ORACLE_HOME/dcm/bin

• Windows: ORACLE_HOME\dcm\bin

  See Also: Distributed Configuration Management Reference Guide for more information on dcmctl.

Using dcmctl

You must use the DCM utility dcmctl in circumstances such as:

• Managing clusters and farms of Oracle Application Server instances. Manage the configuration of individual components, such as OC4J, Oracle HTTP Server instances, and Oracle Process Manager and Notification Server, or Java Authentication and Authorization Service.

• Performing cluster-wide OC4J application deployment.

• Managing versions of configuration with archive, save and restore, and import and export functions.

  See Also: Distributed Configuration Management Reference Guide for detailed information regarding dcmctl and the commands required to perform the above mentioned tasks.

Starting, Stopping, and Restarting Oracle HTTP Server

Oracle HTTP Server is managed by Oracle Process Manager and Notification Server (OPMN). You can use Oracle Enterprise Manager Application Server Control to start, stop, and restart the server.

See Also: Chapter 7, "Application Server Control Management"

For command-line management, you can use the opmnctl utility to start, stop, and restart the server.

You must always use OPMN to start, stop and restart Oracle HTTP Server. Otherwise, the configuration management infrastructure cannot detect or communicate with the Oracle HTTP Server processes, and problems may occur.

Note: Do not use the apachectl utility to manage the Oracle HTTP Server.

To determine the state of Oracle HTTP Server, use the following command:

opmnctl status

The processes are listed with their current state (Up, Down, etc.)

Starting Oracle HTTP Server

To start Oracle HTTP Server, use the startproc command:

• UNIX: ORACLE_HOME/opmn/bin> opmnctl [verbose] startproc ias-component=HTTP_Server

• Windows: ORACLE_HOME\opmn\bin> opmnctl [verbose] startproc ias-component=HTTP_Server

Stopping Oracle HTTP Server

To stop Oracle HTTP Server, use the stopproc command:

• UNIX: ORACLE_HOME/opmn/bin> opmnctl [verbose] stopproc ias-component=HTTP_Server

• Windows: ORACLE_HOME\opmn\bin> opmnctl [verbose] stopproc ias-component=HTTP_Server

Restarting Oracle HTTP Server

Restarting Oracle HTTP Server performs a graceful restart, which is invisible to clients. In a graceful restart, on UNIX, a USR1 signal is sent. When the process receives this signal, it tells the children to exit after processing the current request. (Children that are not servicing requests exit immediately.)

The parent re-reads the configuration files and re-opens the log files, replacing the children with new children in accordance with the settings it finds when re-reading the configuration files. It always observes the process creation settings (MaxClients, MaxSpareServers, MinSpareServers) specified, and takes the current server load into account.

To restart Oracle HTTP Server, use the restartproc command:

• UNIX: ORACLE_HOME/opmn/bin> opmnctl [verbose] restartproc ias-component=HTTP_Server

• Windows: ORACLE_HOME\opmn\bin> opmnctl [verbose] restartproc ias-component=HTTP_Server

  See Also: Oracle Process Manager and Notification Server Administrator's Guide for more information on opmnctl command options.