Answer:

Enabling gzip compression for text based output such as HTML can greatly improve the response of user.

If you are using nginx, it is easy by adding the following lines in your nginx.conf

gzip  on;
gzip_min_length  1000;
gzip_proxied     expired no-cache no-store private auth;
gzip_types text/plain text/html text/css application/json application/x-javascript text/javascript text/xml application/xml;

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Answer:

To check which Apache modules are loaded, in RHEL/Fedora/CentOS, type

# httpd -M

In Debian/Ubuntu

# sudo apache2ctl -M

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Answer:

To deny access for Subversion (svn) related files under Apache, add the following lines to the Apache configuration (httpd.conf)

<DirectoryMatch .*\.svn/.*>
    Deny From All
</DirectoryMatch>

And restart Apache to take effect.

# apachectl -k graceful

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Answer:

If you are running in Red Hat Linux/ Fedora/ CentOS

# httpd -V
....
Architecture:   64-bit
Server MPM:     Prefork
  threaded:     no
    forked:     yes (variable process count)
...

If you are running in Debian/ Ubuntu, you can use apache2 -V, which get the same output as above.

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Answer:

1. Using aptitude

# sudo aptitude install nginx

2. Start it

# sudo /etc/init.d/nginx start

3. Stop it

# sudo /etc/init.d/nginx stop

4. Restart it

# sudo /etc/init.d/nginx restart

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Answer:

Assume you have got your certificate file (server.crt) from a CA, and you also have a private key (server.key).

1. Compile Nginx to support SSL

# ./configure --with-http_ssl_module

2. Add the following line in nginx.conf

server {
    server_name YOUR_DOMAINNAME_HERE;
    listen 443;
    ssl on;
    ssl_certificate /usr/local/nginx/conf/server.crt;
    ssl_certificate_key /usr/local/nginx/conf/server.key;
}

3. Restart Nginx

Reference: http://wiki.nginx.org/NginxHttpSslModule

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Answer:

In the Nginx configuration (nginx.conf), the default worker_processes is 1.

e.g.

worker_processes  1;

However, as nowadays most servers are multi-core/multi-processor machine, it is a waste to only use 1 worker process.

The recommended worker_processes is equal to the number of CPU cores, e.g. if you have a dual Quad Core server, you should set to 8.

worker_processes  8;

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Answer:

To remove the Apache default welcome page under Debian/Ubuntu,

1. Remove the welcome page configuration

# a2dissite default

2. Restart Apache

# sudo /etc/init.d/apache2 restart 

That's all.

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Answer:

If you have a PHP script and want it run under in command line only, not in the web server context, you can use the following method.

<?php

if ( php_sapi_name() != "cli" ) {
    print "This script must be run from the command line\n";
    exit();
}

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Answer:

Server Side Includes (SSI) is a simple mechanism that allow you to add dynamic elements into your HTML file without playing with complicated scripting languages such as PHP or Perl.

To enable it under Apache, add the following lines to the Apache configuration (httpd.conf)

<IfModule mod_include.c>

    AddType text/html .shtml
    AddOutputFilter INCLUDES .shtml

</IfModule>

Restart Apache to take effect

# apachectl -k graceful

Now all yout .shtml files be will parsed and SSI related tags will be evaluated.

To see what SSI directives you can use, check out the following document:

http://httpd.apache.org/docs/2.2/mod/mod_include.html

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