The server name according to the UseCanonicalName directive. | |
%v | The canonical ServerName of the server serving the request. |
You can put a conditional in front of each variable to determine whether the variable is displayed. If the variable isn't displayed, — is displayed instead. These conditionals are in the form of a list of numerical return values. For example, %!401u displays the value of REMOTE_USER unless the return code is 401.
You can then specify the location and format of a log file by using the CustomLog directive:
CustomLog logs/access_log common
If it isn't specified as an absolute path, the location of the log file is assumed to be relative to the ServerRoot.
You will use these commands when managing your Apache web server in Fedora:
> apachectl — Server control shell script included with Apache
> system-config-httpd — Red Hat's graphical web server configuration tool
> httpd — The Apache web server
> konqueror — KDE's graphical web browser
> elinks — A text-based, graphical menu web browser
> firefox — The premier open source web browser
Reference
> http://news.netcraft.com/archives/web_server_survey.html — A statistical graph of web server usage points out that Apache is, by far, the most widely used server for Internet sites.
> http://www.apache.org/ — Extensive documentation and information about Apache are available at The Apache Project website.
> http://apachetoday.com/ — Another good Apache site. Original content as well as links to Apache-related stories on other sites can be found at Apache Today's site.
> http://modules.apache.org/ — Available add-on modules for Apache can be found at The Apache Module Registry website.
There are several good books about Apache. For example, see
CHAPTER 18
Administering Database Services
This chapter is an introduction to MySQL and PostgreSQL, two database systems that are included with Fedora. You'll learn what these systems do, how the two programs compare, and how to consider their advantages and disadvantages. This information can help you choose and deploy which one to use for your organization's data base needs.
The database administrator (DBA) for an organization has several responsibilities, which vary according to the size and operations of the organization, supporting staff, and so on. Depending on the particular organization's structure, if you are the organization's DBA, your responsibilities might include the following:
> Installing and maintaining database servers — You might install and maintain the database software. Maintenance can involve installing patches as well as upgrading the software at the appropriate times. As DBA, you might need to have root access to your system and know how to manage software (refer to Chapter 2, 'Fedora Quick Start'). You also need to be aware of kernel, file system, and other security issues.
> Installing and maintaining database clients — The database client is the program used to access the database (you'll learn more about that later in this chapter, in the section 'Database Clients'), either locally or remotely over a network. Your responsibilities might include installing and maintaining these client programs on users' systems. This chapter discusses how to install and work with the clients from both the Linux command line and through its graphical interface database tools.
> Managing accounts and users — Account and user management includes adding and deleting users from the database, assigning and administering passwords, and so on. In this chapter, you will learn how to grant and revoke user privileges and passwords for MySQL and PostgreSQL while using Fedora.
> Ensuring database security — To ensure database security, you need to be concerned with things such as access control, which ensures that only authorized people can access the database, and permissions, which ensure that people who can access the database cannot do things they should not do. In this chapter, you will learn how to manage Secure Shell (SSH), web, and local GUI client access to the database. Planning and overseeing the regular backup of an organization's database and restoring data from those backups are other critical components of securing the database.
> Ensuring data integrity — Of all the information stored on a server's hard disk storage, chances are the information in the database is the most critical. Ensuring data integrity involves planning for multiple-user access and ensuring that changes are not lost or duplicated when more than one user is making changes to the data base at the same time.
A Brief Review of Database Basics
Database services under Linux that use the software discussed in this chapter are based on a /etc/passwd file. Another example could be a simple address book that might look something like this:
Doe-John-505 Some Street-Anytown-NY-12345-555-555-1212
You can use standard Unix tools such as grep, awk, and perl to search for and extract information from this primitive database. Although this might work well for a small data base such as an address book that only one person uses, flat file databases of this type have several limitations:
