1
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 the server, access the Oracle HTTP Server main page, and stop and restart the server.

Note: You can use Oracle Enterprise Manager for administering the Oracle HTTP Server. Oracle Enterprise Manager provides a Web-based tool that allows you to perform some of the management tasks described in this book. For more information, see the Oracle9i Application Server Administrator's Guide.

This chapter contains the following topics:

• Oracle HTTP Server Features

• Oracle HTTP Server Support

• Starting, Stopping, and Restarting the Oracle HTTP Server

• Starting the Oracle HTTP Server

• Stopping the Oracle HTTP Server

• Restarting the Oracle HTTP Server

Oracle HTTP Server Features

The Oracle HTTP Server provides a robust, reliable web server (that is based on the Apache HTTP Server version 1.3.22), pre-configured to:

• Provide a Servlet 2.3 container with Oracle9iAS Containers for J2EE (OC4J).

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

• Provide single sign-on capability.

  See Also: Oracle9i Application Server Security Guide.

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

  See Also: Oracle9i Application Server Security Guide.

• Execute Perl scripts in the same process as the Oracle HTTP Server.

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

  See Also: Oracle9i Application Server mod_plsql Users Guide

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

• Provide infrastructure for Business Components for Java (BC4J).

• Support the Java Server Pages (JSP) specification v.1.1.

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

Oracle HTTP Server Support

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

• Modules included in the Oracle distribution, except as noted in the table in "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 only.

Oracle HTTP Server Modules

The table below identifies the modules shipped with the Oracle HTTP Server. 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	UNIX systems only.
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_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
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	Not shipped by Oracle.
mod_negotiation	Yes
mod_oc4j	Yes	Oracle module. Recommended servlet container; enabled by default in Oracle configuration.
mod_oprocmgr	Yes	Oracle module.
mod_oradav	Yes	Oracle module.
mod_ossl	Yes	Oracle module.
mod_osso	Yes	Oracle module.
mod_perl	Yes	Third-party module.
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	UNIX systems only.
mod_userdir	Yes
mod_usertrack	Yes
mod_vhost_alias	Yes

Starting, Stopping, and Restarting the Oracle HTTP Server

Oracle HTTP Server is managed by Distributed Configuration Management (DCM). There are two ways to access DCM: through the Oracle Enterprise Manager graphical user interface, and the command-line utility dcmctl, located in ORACLE_HOME/dcm/bin (UNIX) or ORACLE_HOME\dcm\bin (Windows).

See Also: Oracle9i Application Server Administrator's Guide

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

To determine the state of the Oracle HTTP Server, use the getstate command with the verbose option:

dcmctl getstate -v 

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

The dcmctl commands are listed in Table 1-2.

Table 1-2 dcmctl commands

Command	Result
dcmctl start -ct ohs	Starts the Oracle HTTP Server process in the local instance.
dcmctl restart -ct ohs	Restarts the Oracle HTTP Server process in the local instance ('graceful' restart).
dcmctl stop -ct ohs	Stops the Oracle HTTP Server processes in the local instance.

To start, stop, and restart HTTP Server processes in clustered environments, the command must include cluster and/or instance options to specify the target OHS processes. For example:

dcmctl start -cl myCluster -i myInstance -ct ohs

See Also: Oracle9i Application Server Administrator's Guide for more information about clustered environments and DCM.

Starting the Oracle HTTP Server

To start the Oracle HTTP Server, use the start command:

ORACLE_HOME/dcm/bin>dcmctl start -ct ohs (UNIX)

ORACLE_HOME\dcm\bin>dcmctl start -ct ohs (Windows)

Stopping the Oracle HTTP Server

To stop the Oracle HTTP Server, use the stop command:

ORACLE_HOME/dcm/bin>dcmctl stop -ct ohs (UNIX)

ORACLE_HOME\dcm\bin>dcmctl stop -ct ohs (Windows)

This command sends a TERM signal to the parent process, causing it to terminate all of the child processes (which could take several seconds). After all of the children are terminated, the parent exits. Any client requests in progress are terminated, and no other requests are served until the server is started again.

Restarting the Oracle HTTP Server

Restarting the Oracle HTTP Server performs a graceful restart, which is invisible to clients. In a graceful restart, 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 the Oracle HTTP Server, use the restart command:

ORACLE_HOME/dcm/bin>dcmctl restart -ct ohs (UNIX)

ORACLE_HOME\dcm\bin>dcmctl restart -ct ohs (Windows)