3
Managing Server Processes

This chapter provides an overview of the Oracle HTTP Server processes and provides information on how to regulate, and monitor these processes. Topics include:

• HTTP Server Processing Model

• Limiting the Number of Processes and Connections

• Getting Information about Processes

  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.

HTTP Server Processing Model

Once Oracle HTTP Server is started, the system is ready to listen for and respond to http(s) requests. The request processing model is different for Window and UNIX.

On UNIX, when Oracle HTTP Server is started, a single parent process launches several child processes that listen and promptly respond to client requests. The main httpd parent process continues to run as the root user if the root.sh script was run during installation or if the user was logged in as root. However, the child processes run as a less privileged user. The User and Group directive are used to set the privileges for the child processes. The child processes must be able to read all the content that will be served.

On Windows, Oracle HTTP Server launches a single parent process and one child process. The child process creates multiple threads that listen and respond to client requests.

You must decide how you want to set Oracle HTTP Server to handle processes.

ServerType

This directive provides two options for this:

• inetd: This starts up a new child process every time a request comes in. The program exits once the request is dealt with. This setting eliminates the option of having several child processes in waiting. It can be slower and expensive, but more secure. This is applicable to UNIX only.

• standalone: This enables several waiting child processes and requires the server to be started only once. This is the default, and recommended setting for a busy Web site. This is applicable to UNIX only.

  See Also: "ServerType directive" in the Apache Server documentation

You must specify the Group and User under which the server will answer requests. This is applicable to UNIX only.

Group

This specifies the group under which the server will answer requests. In order to use this directive, the standalone server must be run initially as root. It is recommended that you create a new group for running the server.

See Also: "Group directive" in the Apache Server documentation

User

This specifies the userid to which the server will answer requests. In order to use this directive, the standalone server must be run initially as root. The user should have privileges to access files that are available for everyone, and the user should not be able to execute code which is not meant for httpd requests. It is recommended that you set up a new user for running the server.

See Also: "User directive" in the Apache Server documentation

Limiting the Number of Processes and Connections

The following directives control and limit the number of child processes or simultaneous requests:

• StartServers

• ThreadsPerChild

• MaxClients

• MaxRequestPerChild

• MaxSpareServers

• MinSpareServers

StartServers

This sets the number of child server processes created when Oracle HTTP Server is started. The default is set at 5. This is applicable to UNIX only.

See Also: "StartServers directive" in the Apache Server documentation

ThreadsPerChild

This controls the maximum number of child threads handling requests. This is applicable to Windows only.

See Also: "ThreadsPerChild directive" in the Apache Server documentation

MaxClients

This limits the number of requests that can be dealt with at one time. The default and recommended value is 150. This is applicable to UNIX only.

See Also: "MaxClients directive" in the Apache Server documentation

MaxRequestPerChild

This controls the number of requests a child process handles before it dies. This value should be specified again if the machine is rebooted. If you select the value to be 0, which is the default, then the process will never die. This is applicable to UNIX only.

See Also: "MaxRequestPerChild directive" in the Apache Server documentation

MaxSpareServers

This sets the maximum number of idle child server processes. An idle process is one which is running but not handling a request. The parent process will kill off idle child processes that exceed the value set for this directive. The default is set at 10. This is applicable to UNIX only.

See Also: "MaxSpareServers directive" in the Apache Server documentation

MinSpareServers

This sets the minimum number of idle child server processes. An idle process is one which is running but not handling a request. The parent process will create new children at the maximum rate of one process per second if there are fewer processes running. The default is set at 5. This is applicable to UNIX only.

See Also: "MinSpareServers directive" in the Apache Server documentation

Getting Information about Processes

To monitor HTTP Server processes, you can use the performance monitor on Windows, or the ps utility on UNIX.

See Also: Oracle9i Application Server Performance Guide and your operating system documentation for more information.

You can also monitor the HTTP Server processes using the Oracle Enterprise Manager Oracle9iAS Home Page.

See Also: Oracle9i Application Server Administrator's Guide

If a network error occurs on a device such as a router or firewall between the application server and the database, JDBC connections may stop responding. In this situation, you must stop the HTTP Server and JServ processes manually, and there may be a delay in stopping the processes.