Apache Problem due to (24)Too many open files - Solution

After running web services on Apache for few years, my web suddenly could not be accessed because of given an error "HTTP WARNING: HTTP/1.1 403 Forbidden".

When checking the Apache Error log, I found an error message as shown below.

(24)Too many open files: /var/www/html/.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable

The solution to this problem is to increase the maximum number of open files and user processes by the following settings.


vim /etc/security/limits.conf 
root soft nofile 32768 
root hard nofile 32768 
root soft nproc 4096  
root hard nproc 4096

How to install LAMP on Ubuntu ?

1. Install Apache

2. Install MySQL

3. Install PHP

Restart Server

Check PHP

You can check your PHP by executing any PHP file in folder /var/www/html

Install Apache, PHP, and Memcached on CentOS

Install Apache 

# yum install update 

Setup Apache

# vim /etc/httpd/conf/httpd.conf

<Directory "/var/www/html">
   AllowOverride all
#
# Controls who can get stuff from this server.
#
    Order allow,deny
    Allow from all

</Directory>

Install PHP

# yum install php

# yum install php-gd php-ldap php-odbc php-pear php-xml php-xmlrpc php-mbstring php-snmp php-soap curl curl-devel

curl-d

Check PHP

# vim /var/www/html/info.php

<?php
phpinfo();
?>

// Test Link

http://Server`s IP/info.php

Install Memcached

#yum install memcached

Start Memcached

# chkconfig --level 235 memcached on

# /etc/init.d/memcaached start

# /etc/init.d/memcached sratus

Install Memcached Perl Library

Install perl library for Memcached.

# yum install perl-Cache-Memcached

Install Memcached Python Library

Install python library for Memcached.

# yum install python-memcached

Restart Apache

Restart the Apache service to reflect changes.

# /etc/init.d/httpd restart
OR
# service httpd restart

Check Memcache

# vim /var/www/html/memtest.php

<?php
$memcache = new Memcache;
$memcache->connect('localhost', 11211) or die ("Could not connect");
$version = $memcache->getVersion();
echo "Server's version: ".$version."<br/>\n";
$tmp_object = new stdClass;
$tmp_object->str_attr = 'test';
$tmp_object->int_attr = 123;
$memcache->set('key', $tmp_object, false, 10) or die ("Failed to save data at the server");
echo "Store data in the cache (data will expire in 10 seconds)<br/>\n";
$get_result = $memcache->get('key');
echo "Data from the cache:<br/>\n";
var_dump($get_result);
?>

// Test Link
http://Server`s IP/memtest.php

Restrat Apache

# /etc/init.d/httpd restart

How to optimize Apache, setup Memcached and PHP on Ubuntu ?

Install and setup Apache

// Install Apache2  

sudo apt-get install apache2

// Edit Config

vim /etc/apache2/apache2.conf

<IfModule mpm_prefork_module>

StartServers       10

MinSpareServers    10

MaxSpareServers   10

ServerLimit      256

MaxClients       256

MaxRequestsPerChild 10000

</IfModule>

// check module

apachectl -V | grep -i mpm

// disable event

a2dismod mpm_prefork

// Enable Prefork

a2enmod mpm_prefork

// Restart Apache

service apache restart

Install Memcahced

// Install memcached

sudo apt-get update

sudo apt-get install php5 php5-memcache

sudo apt-get install memcached

sudo apt-get install php-pear

sudo apt-get install build-essential

sudo pecl install memcache

// restart memcached

sudo service memcached restart 

You should add "extension=memcache.so" to php.ini  and restart Apache 

 

// Check Memcache

ps aux | grep memcache 

Install PHP

sudo apt-get install php5 php5-mysql

sudo apt-get install --purge mysql-client mysql-common 

// Remove MYSQL

sudo apt-get remove --purge mysql-server mysql-client mysql-common

sudo apt-get autoremove

sudo apt-get autoclean

Solutions to common problems

Problem1:  

The mcrypt extension is missing. Please check your PHP configuration.

Solution:

sudo apt-get install php5-mcrypt

sudo apt-get install mcrypt

Problem2:  

Need CURL PHP extension to connect facebook

Solution:

sudo apt-get install curl libcurl3 libcurl3-dev php5-curl

Problem3:

Echo PHP Not Support at HTML

Solution:

vim /etc/php5/apache2/php.ini

short_open_tag = On  

service apache2 stop

service apache2 start

   

chown -R www-data /var/www/html/
chmod -R u+w /var/www/html/