1. In which folder are Java Applications stored in Apache?

Java applications are not stored in Apache, it can be only
connected to a other Java webapp hosting webserver using the
mod_jk connector

2. What is struct and explain its purpose?

A struts is a open source framework for creating a Java web

3. Tell me Is running apache as a root is a security risk?

No.root process opens port 80, but never listens to it, so
no user will actually enter the site with root rights. If
you kill the root process, you will see the other kids
disappear as well.

4. What is htpasswd?

htpasswd is used for allowing user to authenticate for a
particular web page. such as you are running 2 or more web
pages through virtual hosting or any other method and want
to provide access for any user to access a particular page
with authentication then you can use the htpasswd for
creating user authentication file. when you run the command
htpasswd with the option -c and -m for any user it will
create a file named htpasswd in which an entry for user name
and encrypted passswd will create.

5. What is mod_vhost_alias?

This module creates dynamically configured virtual hosts, by
allowing the IP address and/or the Host: header of the HTTP
request to be used as part of the pathname to determine what
files to serve. This allows for easy use of a huge number of
virtual hosts with similar configurations.

6. What is ServerType directive in Apache Server?

It defines whether Apache should spawn itself as a child
process (standalone) or keep everything in a single process
(inetd). Keeping it inetd conserves resources. This is
deprecated, however.

7. How to set up a virtual host in Apache?

apache provide two type of virtual hosting 1- ip based and
2- name based.
to configure name based your dns should work properly.
go to the /etc/httpd/conf/httpd.conf file and remove # from
the start of of Namevertualhost *:80
and than at the end of file write the content below

<VirtualHost "IP of your apache server":80>
ServerAdmin root@krishna.com
DocumentRoot /var/www/krishna/krishna.html
DirectoryIndex krishna.html
ServerName www.krishna.com
ErrorLog /home/apache/logs/error/hostedsites/error_log
TransferLog /home/apache/logs/access/hostedsites/access_log
restart your httpd service by running the command
Service httpd restart or /etc/init.d/httpd restart

8. How to check for the httpd.conf consistency and any
errors in it?

We can check syntax for httpd configuration file by using
following command.

httpd -S

9. What does apachectl graceful do?

Gracefully restarts the Apache httpd daemon. If the
daemon is not running, it is started. This differs from a
normal restart in that currently open connections are
not aborted. A side effect is that old log files will not
be closed immediately. This means that if used in a log
rotation script, a substantial delay may be necessary to
ensure that the old log files are closed before
processing them. This command automatically checks
the configuration files as in configtest before
initiating the restart to make sure Apache doesn?t die.
This is equivalent to apachectl -k graceful.

( excerpt from manual page of apachectl )

Actually it sends a SIGUSR1 for a restart. The USR1 or
graceful signal causes the parent process to advise the
children to exit after their current request (or to exit
immediately if they're not serving anything). The parent
re-reads its configuration files and re-opens its log files.
As each child dies off the parent replaces it with a child
from the new generation of the configuration, which begins
serving new requests immediately.

10. How to to stop Apache?

To stop apache you can use.

/etc/init.d/httpd stop command.

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