Use any of the following resources for information on your Web server. There is also a list of concept definitions available at this site.
Configuration and Administration form help.
You can use your Web browser (such as Netscape Navigator or Microsoft Internet Explorer) to work with the IBM HTTP Server Configuration forms and
Administration forms. With your Web browser and the forms you can perform all of the configuration and administrative tasks on your server. A list of options in the left frame of the window helps you navigate through all the configuration and administrative tasks. For instance with the Add Internet Users form you can grant Internet access to additional users. The new users only have access to the Web server resources you specify, and they do not have actual AS/400 User Profiles. You can use any browser capable of handling Java script and frames to work with the forms.
Each Configuration and Administration form features a help window you can consult for assistance as you complete configuration tasks or server administration tasks. You use a browser, just as you are using now, to interact with the
Configuration and Administration forms and the corresponding help files. You can access the help files by clicking the question mark icon in the title of any form.
IBM HTTP Server for AS/400 Webmaster’s Guide.
The IBM HTTP Server Webmaster’s Guide describes the advanced function and configuration of your server. This book contains procedures for changing configurations, using server directives, making your communications secure, protecting your server, enabling logging of server activity, and troubleshooting problems. You must have Internet access to view this book.
IBM HTTP Server Web Programming Guide.
The IBM HTTP Server for AS/400 Web Programming Guide tells you how to write external programs that interact with the Web server. The Web Programming Guide includes details on working with CGI, Server API, and Java servlets. You must have Internet access to view this book.
World wide Web sites.
Bookmark the IBM HTTP Server for AS/400 Web site for the latest information and updates to the Web server product. You must have Internet access to reach this site.
IBM HTTP Server concepts
This is your quick access to definitions for common topics that the Web serving articles mention. Many articles link to the concepts that are listed below, as they are relevant to particular subjects.
v “Agent log”
v “Application Server Manager” v “Caching”
v “CGI” on page 95 v “GIF” on page 95 v “HTML” on page 95 v “Image map” on page 96 v “Internet users” on page 96 v “IP address” on page 96 v “JPEG” on page 96
v “Logs and reports” on page 96 v “Web server methods” on page 96 v “MIME” on page 98
v “Net.Data” on page 98 v “Proxy server” on page 98 v “Referrer log” on page 98
v “Server configuration” on page 99 v “Server instance” on page 99 v “SSL” on page 100
v “TCP/IP” on page 100 v “Validation list” on page 100 v “Virtual host” on page 100
Agent log
The agent log indicates which Web browser the client used to access a Web page. By default, the server writes an entry to the agent log each time a client sends the server a request. For every entry that is made in the access log, the agent log has a corresponding entry. This entry indicates the browser that is used to display the page or file that is requested by the client.
Application Server Manager
Application Server Manager is a separate product from your IBM HTTP Server. If you choose to configure your server to allow or support servlets, then you might want to do additional configuring with the Application Server Manager.
Caching
Your cache stores materials which are in demand. This means that the system does not need to search for the original source every time these materials are accessed. Changes you make to the Local caching form influence the performance of your server. Using local caching, you can specify files you want to load into the server’s memory each time you start the server. By keeping your most frequently-cached files loaded in the server’s memory, you can improve your server’s response time for those files. For example, if you load your server’s welcome page into memory
at startup by adding it to the cache list, the server can handle requests for the page much more quickly than if it had to read the file from a disk. Keep in mind that for each file you load into memory, you are making that amount of memory unavailable for other uses which can affect performance.
Proxy caching allows you to have the proxy server store the documents it retrieves from other servers in a local cache. The server can then respond to subsequent requests for the same documents without having to retrieve them from other servers. This can improve response time. This also allows users of your internal network to access documents on the Internet.
CGI
Common gateway interface (CGI) is a standard that is supported by almost all Web servers. It defines how information is exchanged between a Web server and an external program (CGI program).
The CGI specification dictates how CGI programs get their input and how they produce any output. CGI programs process data that is received from browser clients. For example, the client fills out a form and sends the information back to the server.
GIF
GIF might be the most common file extension you see on the Internet because it produces a lower quality image than the .jpeg. The files are smaller, and they download faster than .jpeg files. A smaller graphic file will appear faster to anyone who views your page.
HTML
You can use Hypertext markup language (HTML) to create your Web pages. HTML is a simple tagging language that is widely used on most of the Web pages on the Internet. You can view the HTML source code on any page with your browser, whether it is an Internet Web page or an intranet Web page.
Most browsers allow for viewing the source code of a Web site you visit. Within a
Viewmenu, the menu names for this task may vary by browser. Netscape Navigator uses Page source while Internet Explorer uses Source.
When you view the HTML, you will see that it uses a series of tags to structure the page. Each tag appears in brackets. For instance, if you want your product name to appear in bold type, it would look like this:
<B>IBM HTTP SERVER</B>
For an easy way to learn about HTML and generate ideas for your Web pages, spend some time by viewing pages on the Internet. When you find a page that looks interesting, view the document source to get an idea on how to structure your own pages. You can also search the Internet for tutorials and instructional pages on HTML.
You can create your HTML pages by using any editor capable of producing flat text files. However, if you use a simple text editor, such as Windows Notepad, you will have to manually type each HTML tag. If you do not want to type the tags, you can use an HTML editor. If you search the Internet for HTML editors, you will
find that many editors available on a try-before-you-buy-basis. Some word
processing programs and desktop publishing programs will let you transform your documents into HTML format.
Soon, you will get an idea of how the HTML tags work. Then you can create your own pages or use the sample page as a template. You might plan to use graphics in your site, too.
Image map
Many sites make great use of graphic files by using them as navigation tools, known as image maps. If you find a graphic to click on that gets you to another page, you might be using an image map. Searching the Internet for information on image maps will give you ideas on how to use them and how to create them.
Internet users
In the broadest terms, an Internet user is anyone who uses the Web. You may want to narrow that definition for using your server. Internet users may be employees on your internal intranet, clients on the Internet, or both. Keep in mind that the two groups of Internet users may have very different needs. Internet users are defined in validation lists and exist independently of AS/400 user profiles, and only your IBM HTTP Server uses them.
IP address
The Internet Protocol (IP) address is an identification code for Internet or intranet communication. The address identifies each sender and receiver, with code for the network as well as the particular station from which the message is sent.
An example of an IP address would be
9.67.106.79
JPEG
JPEG might be the format you choose if your graphics are photographs and
preserving the color is important to you. Because they display a high quality image with more colors than a .gif file, the .jpeg files are larger and require a longer download time. If you use a .jpeg file on your Web page, make sure that it is worth the wait for anyone visiting your page.
Logs and reports
You configure logs to collect information from various sources in your server. You configure reports to deliver specific information from the logs. Logs and reports exist for you to keep track of and examine the activities concerning your server.
Web server methods
When your server receives a URL request, the request header contains coding that asks the server to perform one of its supported tasks. These tasks are known as methods.
Your server supports the following methods:
v Get — Enable the generic envelope type (GET) method and the server returns whatever data the URL identifies. If the URL refers to an executable program, the server returns the output of the program.
is the default setting.
v Head — Enable the HEAD method and the server returns the HTTP document header without the document body.
Enabled
is the default setting.
v Post — Select POST to indicate that the input to the CGI program will be passed to the CGI program in the standard input stream.
Disabled
is the default setting for every server instance except administration (ADMIN). The server administrator handles POST method requests submitted by a remote HTTP client by selecting Exec as the Action on the Request routing form. This enables CGI programs to run. Unless you select Exec to enable CGI programs, the server will not honor a request to run a CGI program. Selecting Exec can enable all the CGI programs in a library, or it can enable only specific programs within various libraries.
Note: The ADMIN server instance uses the POST method to submit
configuration updates. If you disable this method for the ADMIN server instance, you will not be able to make server configuration updates by using the administration forms. By default, the POST method is enabled for the ADMIN server instance.
v Options — Enable the OPTIONS method and the request information about the communications options on the request or the response chain that is identified by the URL. This method allows a client to determine the options and
requirements associated with an object, or the capabilities of a server. No action on or retrieval of the object is necessary.
Enabled
is the default setting.
v Trace — Enable the TRACE method and the server echoes the request message sent by the client. This method allows the client to see what is being received at the other end of the request chain. The client can then use that data for testing or diagnostic information. The content type of the response is
message/http Enabled
is the default setting.
v Connect — Enable the CONNECT method and your server can establish an SSL tunneling session between a client (such as Netscape Navigator) and a remote server through a proxy server. The sessions between the client and the proxy and between the proxy and the remote server are secure. The proxy cannot access the data sent to the client. The proxy server can be a base or secure server.
Disabled
is the default setting. To enable SSL tunneling, go to the Proxy server settings and specify an SSL tunneling port.
v Put — The request contains data and a URL. The server stores the resource identified in the URL. If the resource already exists, PUT replaces it. If the resource does not exist, PUT creates it. Because PUT typically lets clients add or
replace information on your server you must use protection setups to define who can use this method for which files.
Disabled
is the default setting.
v Delete — Enable the Delete method and the server deletes the object identified by the URL. After the object is deleted, the URL is not valid. Because delete typically lets clients delete information from your server, you must use protection setups to define who can use this method and which files can be deleted.
Disabled
is the default setting.
MIME
Multipurpose Internet Mail Extension (MIME) is what allows users to send information over e-mail in forms other than simple text. MIME allows for electronic transmission of audio, video, applications, images, and so forth.
Many MIME types, such as GIFs and PostScript files, are predefined. You can also define your own MIME types.
MIME types allow Web browsers to output files which are not in an HTML format.
Net.Data
A sample Net.Data search and a Net.Data search results macro are available for you to customize the Web pages that users will see when using the search engine. You can change the HTML, add graphics, or reorganize the page as you choose. Do not change any functional parts of the macro, since this may cause errors in the underlying code.
Edit a copy of the macros, choose a directory to contain them, and then set up a configuration file which allows access to these macros.
Proxy server
Clients can ask a proxy server to retrieve documents on its behalf from other servers. In this way, the proxy server performs as both an HTTP Server and a client. It is a server with respect to clients making requests and it is a client with respect to other servers.
You can configure your IBM HTTP Server to handle HTTP proxy requests in addition to regular HTTP requests. You may configure your server to function strictly as a proxy, or as both a proxy and a normal server.
The proxy server’s greatest advantage is that it’s cache can serve all of your users. This improves response time for frequently requested Internet sites. Running a proxy server increases the traffic on your server. You may want to set up a separate server instance as your proxy server.
Referrer log
The referrer log identifies the Web page that refered (or linked to) the requested Web page. If the server is configured to log the referrer, the server writes an entry to the referrer log each time a client sends the server a request. For each entry that
is made in the access log, the referrer log has a corresponding entry. This entry indicates which page refered to the page that the client requested. If no page refered to the requested page, the entry is two quotation marks (″ ″). If a single page accesses images or other files, they will look like separate requests. Each will have a separate entry in these log files.
The referrer information can also be logged in the access log if the extended log format is being used. If the access log is configured to use the extended log format, and the referrer log is also configured, the server will log the referrer for each request in both the access log entry and the referrer log.
Server configuration
The behavior of an instance of your IBM HTTP Server is controlled by the configuration for that instance. The server uses the information in a configuration to determine how to respond to requests from a client browser.
A configuration is actually a file made up of statements called directives. Each configuration has a single unique name. You can change the directive statements by using the Configuration and Administration forms. Your server has default settings for its configurations. However, you can create and delete your own configurations, change configurations once you create them, and display current values for a configuration.
Server instance
The term ″instance″ describes each separate server when a single system starts multiple Web servers.
Multiple HTTP servers may be defined and running concurrently on an AS/400. Each of those servers is called an instance and is named. The Web server uses configuration files as a basis for the server instances. The server comes with a configuration file called CONFIG and another configuration file called ADMIN. It also comes with two server instances; the ADMIN (*ADMIN) server instance (which is based on the ADMIN configuration) and the DEFAULT server instance (which is based on the CONFIG configuration).
Because you can run multiple server instances, you have the ability to support multiple Web sites from the same Web server on your AS/400.
Running multiple server instances on a single AS/400 server is analogous to running multiple HTTP server machines (for example, multiple PC servers), each with a single instance.
Each server instance runs in the QHTTPSVR subsystem. Each instance consists of one HTTP server job in the QHTTPSVR subsystem, along with one or more helper jobs.
Depending on the needs of your business, you can run multiple server instances that are customized to the needs of your clients. For example, you may choose to run one server instance for your Internet clients, and one server instance for your intranet clients.
SSL
Secure Sockets Layer (SSL) is a program layer that is set between an application and the Internet’s TCP/IP layers. SSL provides security between a client and your server in message transmission, allowing the server to authenticate the identity of the clients.
SSL uses a security exchange to secure the TCP/IP connection between the client and the server. The exchange occurs after the TCP/IP connection is established. During the exchange, the client and server agree on the security keys that they will use for the session, and the client authenticates the server. After that, your server uses SSL to encrypt and decrypt all of the information in both the request and the server response. This information includes the following:
v The URL that the client requests
v The contents of any form that you submit
v Access authorization information (such as user names and passwords) v All data sent between the client and the server
TCP/IP
Transmission Control Protocol/Internet Protocol (TCP/IP) is the language that is