Working Of Apache Web Server

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In this article, I will examine what apache is how to setup apache for ubuntu or debian and how to view error logs for apache and how to understand what the logs contain which will be useful for web development.

What is Apache?

Apache is the most popular web server on the internet. It is used to serve more than half of all active websites.

The Apache HTTP Server, httpd, is an open source web server developed by the Apache Software Foundation. If you are upgrading from a previous release of Red Hat Enterprise Linux, you will need to update the httpd service configuration accordingly. This section reviews some of the newly added features, and guides you through the update of prior configuration files. Jan 08, 2020 There are quite a few web servers available, like, Apache, Microsoft IIS, Nginx Web Server, LightSpeed Web Server. But, the two most popular ones are-Apache HTTP Server:It is the most popular web server available and is widely used. It is developed and maintained by Apache Software Foundation. Set up an Apache web server on an EC2 instance. Set up an Apache web server on multiple EC2 instances by creating an Auto Scaling group. You can create multiple EC2 instances using Amazon EC2 Auto Scaling, an AWS service that allows you to increase or decrease the number of EC2 instances in a group according to your application needs. Jan 02, 2021 The sole job of the web server is to serve up a stream of text data, and the server has no idea what the date is or how to render it. It simply transmits the data stream to the requesting host. After saving the file, set the ownership to apache.apache. root@testvm1 html# chown apache.apache index.html.

It is fast, reliable, and secure. It can be highly customized to meet the needs of many different environments by using extensions and modules.

Installing Apache on Ubuntu and Debian

If you do not already have Apache installed, you can do so now by issuing the following commands:

If you visit your VPS’s IP address in a web browser, you will get the default Apache index page. We get the following output.

Looking into apache error.log files

In order to effectively manage a web server, it is necessary to get feedback about the activity and performance of the server as well as any problems that may be occuring. The Apache HTTP Server provides very comprehensive and flexible logging capabilities.

Error.log file

The server error log, whose name and location is set by the ErrorLog directive, is the most important log file. This is the place where Apache httpd will send diagnostic information and record any errors that it encounters in processing requests.

It is the first place to look when a problem occurs with starting the server or with the operation of the server, since it will often contain details of what went wrong and how to fix it.

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Explanation of log message

Use Of Apache Web Server In Php

There is certain information that is contained in most error log entries. For example, here is a typical message.

[Sat Aug 20 08:09:38.958885 2016] The first item in the log entry is the date and time of the message.

[:error] The second entry lists the severity of the error being reported.

[pid 1489] Indicates process Id

[client 127.0.0.1:40810] The fourth entry gives the IP address of the client that generated the error.

Fifth one is error message explaining the error.

File and line number

Error logs are easy to understand. Using error logs we can easily figure out the problem in your server or your code and fix it.

For more information about the log files and configuration please visit Apache website Apache provides excellent documentation.

Apache log files were useful for me during web development project Engelsystem. We are developing new features. Interested developers can work with us.

Development: https://github.com/fossasia/engelsystem

Issues/Bugs:https://github.com/fossasia/engelsystem/issues

Customizing Apache for Windows

Apache is configured by the files in the conf subdirectory. These are the same files used to configure the Unix version, but there are a few different directives for Apache on Windows. See the directive index for all the available directives.

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The main differences in Apache for Windows are:

Working Of Apache Web Server Software

  • Because Apache for Windows is multithreaded, it does not use a separate process for each request, as Apache can on Unix. Instead there are usually only two Apache processes running: a parent process, and a child which handles the requests. Within the child process each request is handled by a separate thread.

    The process management directives are also different:

    MaxConnectionsPerChild: Like the Unix directive, this controls how many connections a single child process will serve before exiting. However, unlike on Unix, a replacement process is not instantly available. Use the default MaxConnectionsPerChild 0, unless instructed to change the behavior to overcome a memory leak in third party modules or in-process applications.

    Warning: The server configuration file is reread when a new child process is started. If you have modified httpd.conf, the new child may not start or you may receive unexpected results.

    ThreadsPerChild: This directive is new. It tells the server how many threads it should use. This is the maximum number of connections the server can handle at once, so be sure to set this number high enough for your site if you get a lot of hits. The recommended default is ThreadsPerChild 150, but this must be adjusted to reflect the greatest anticipated number of simultaneous connections to accept.

  • The directives that accept filenames as arguments must use Windows filenames instead of Unix ones. However, because Apache may interpret backslashes as an 'escape character' sequence, you should consistently use forward slashes in path names, not backslashes.

  • While filenames are generally case-insensitive on Windows, URLs are still treated internally as case-sensitive before they are mapped to the filesystem. For example, the <Location>, Alias, and ProxyPass directives all use case-sensitive arguments. For this reason, it is particularly important to use the <Directory> directive when attempting to limit access to content in the filesystem, since this directive applies to any content in a directory, regardless of how it is accessed. If you wish to assure that only lowercase is used in URLs, you can use something like:

  • When running, Apache needs write access only to the logs directory and any configured cache directory tree. Due to the issue of case insensitive and short 8.3 format names, Apache must validate all path names given. This means that each directory which Apache evaluates, from the drive root up to the directory leaf, must have read, list and traverse directory permissions. If Apache2.4 is installed at C:Program Files, then the root directory, Program Files and Apache2.4 must all be visible to Apache.

  • Apache for Windows contains the ability to load modules at runtime, without recompiling the server. If Apache is compiled normally, it will install a number of optional modules in the Apache2.4modules directory. To activate these or other modules, the LoadModule directive must be used. For example, to activate the status module, use the following (in addition to the status-activating directives in access.conf):

    Information on creating loadable modules is also available.

  • Apache can also load ISAPI (Internet Server Application Programming Interface) extensions such as those used by Microsoft IIS and other Windows servers. More information is available. Note that Apache cannot load ISAPI Filters, and ISAPI Handlers with some Microsoft feature extensions will not work.

  • When running CGI scripts, the method Apache uses to find the interpreter for the script is configurable using the ScriptInterpreterSource directive.

  • Since it is often difficult to manage files with names like .htaccess in Windows, you may find it useful to change the name of this per-directory configuration file using the AccessFilename directive.

  • Any errors during Apache startup are logged into the Windows event log when running on Windows NT. This mechanism acts as a backup for those situations where Apache is not yet prepared to use the error.log file. You can review the Windows Application Event Log by using the Event Viewer, e.g. Start - Settings - Control Panel - Administrative Tools - Event Viewer.