Speed up Vbulletin Forum with Memcached

Memcached is a memory caching system. This will help to increase speed of your vbforum . Vb have default support for integrating memchached. I already wrote a document for using memcached with Openx software. Please see the steps below, to see how you can configure memcached in your server and integrate to vbulletin

Install memcached server

Download the memcached server from http://memcached.org/

# wget -c  http://memcached.googlecode.com/files/memcached-1.4.5.tar.gz
# tar -xzf  memcached-1.4.5.tar.gz
# cd memcached-1.4.5/
# yum -y install libevent libevent-devel
# ./configure --prefix=/opt/memcached
# make
# make install

Now install init script . I wrote an init script for redhat and centos servers , you can use it to start/stop memcached.

# wget -c http://downloads.sherin.co.in/memcached.redhar.rc.txt
# mv -f memcached.redhar.rc.txt /etc/init.d/memcached
# chmod 750 /etc/init.d/memcached
# /etc/init.d/memcached start

To start Memcached automatically during reboot add the following lines to /etc/rc.local

# /etc/init.d/memcached start

Next we need to install and configure php-pecl module for memcached.

Install php-pecl memcache

Download the latest stable memcached from http://pecl.php.net/package/memcache

# wget -c http://pecl.php.net/get/memcache-2.2.5.tgz
# tar -xzf  memcache-2.2.5.tgz
# cd memcache-2.2.5/
# phpize
# ./configure
# make
# make install

Now restart apache and create a phpinfo page and test whether the memcache options is showing or not. If it is there then you installed php module . If not you need to check your php.ini settings and enable memcache module

Now we need to configure vbulletin software as follows

Configure Vbulletin

Edit the Vb configuration file includes/config.php and uncomment the following lines

$config['Datastore']['class'] = 'vB_Datastore_Memcached';
$i = 0;
// First Server
$config['Misc']['memcacheserver'][$i]           = '';
$config['Misc']['memcacheport'][$i]                     = 11211;
$config['Misc']['memcachepersistent'][$i]       = true;
$config['Misc']['memcacheweight'][$i]           = 1;
$config['Misc']['memcachetimeout'][$i]          = 1;
$config['Misc']['memcacheretry_interval'][$i] = 15;

Now restart apache server . Your vbulletin now works with memcached. You can see the performance difference within 1 to 2 hours.

GDB for Debugging Linux Software

GDB is a nice tool for debugging linux software and find out its flaws. Let me give an easy way how you can use gdb to debug your application. If you see one of your application crashing or not working well, you can use gdb to debug it and send the result to its developers. The only thing you need to make sure is that , your program must be compiled with the debugger flag ‘-g’ , if not there will be no debugger flags in the software. In general all free and opensource software have gdb feature enabled by default.

Let us take and example here to study GDB . The command is “gedit” . It is an editor in gnome.
Step 1 : Go to shell and start the command with gdb

# gdb  gedit

It will show the following in my box,

sherin@:~$ gdb gedit
GNU gdb (GDB) 7.1-ubuntu
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "i486-linux-gnu".
For bug reporting instructions, please see:
Reading symbols from /usr/bin/gedit...(no debugging symbols found)...done.

Step 2 : Run the command from gdb prompt

(gdb) run
Starting program: /usr/bin/gedit

Now gedit will be open and you can type and save a document.
It will show the debugger output in your gdb terminal

Step 3 : To stop execution use the command kill

(gdb) kill

Step 4: To exit from gdb use the command “quit”

These all are basic to know how you work win gdb.

Now if you need to debug an already running program use the flag –pid=PID

# gdb --pid=10345

If you are a developer , here is a good tutorial for you which will help you to debug your applications easily.

Openx Cluster Handbook – 121 cluster Openx High performance simple cluster based on Nginx, lighttpd/apache

Disclaimer : Please notices this document will help you for configuring an simple highperformance cluster for hosting Openx services. This article is licensed under Creative Commons Attribution-No ncommercial 2.5 India .Please don’t copy and paste the configurations to your server if it is not the hardware that mentioned in the hardware requirements.

1. Introduction

1.1 Why the name 121 Cluster?

1.2 Technology

2. System Requirements

2.1 Load Balancer Node
2.2 Web Servers Node
2.3 Database Server Node

3. Install and Configure Load Balancer

4. Install and Configure Webserver

4.1 File system configuration
4.2 Lighttpd installation
4.3 Apache installation

5. Install and Configure Database Server

6. Optimization

Appendix-A About The Author

Appendix-B License

1. Introduction

This document help you to setup a simple cluster for starters. This configuration using the best and popular software configuration for getting better stability and performance. This can be used for Openx cluster platforms and large vbulletin forums. Please not this is not a high availability solution but cluster. You can build this cluster with a minimum of 4 servers.

1.1 Why the name 121 Cluster?

Let me explain 1-2-1 cluster means ,

  • 1 – Load balancer
  • 2 – Werbserver , or multiple of 2
  • 1 – Database server

So this configuration is based on one load balancer , two or multiple of 2’s of webservers and one database server. Here all are servers there is no need to buy external devices. This is the simplest and well optimized cluster that you can build. You can see a graphical representation of this cluster as below,

1.2 Technology

We are here using Nginx webserver as http load balanced Proxy. It is the most popular proxy application and around 6% of high traffic websites in this world usin nginx. Some example sites using nginx are wordpress.com ,rambler.ru,fastmail.fm

Behind these proxies we use lighttpd as webservers for hosting our application. Lighttpd is a fast webserver with light foot print. It can simply handle millions of requests without increasing server load.It is designed and optimized for high performance environments. With a small memory footprint compared to other web-servers, effective management of the cpu-load, and advanced feature set (FastCGI, SCGI, Auth, Output-Compression, URL-Rewriting and many more) lighttpd is the perfect solution for every server that is suffering load problems.

2. System Requirements

Here we using the best webservers and proxy applications available on industry. It is fully a service based cluster. So no worry about kernel panics and OS corruptions. Also if you have a private LAN across these nodes, it is good to configure it otherwise you need to proxify the access over internet.

2.1 Load Balancer Node

This node is your public node,, That means your Openx/website domain is pointing to this server IP. I recommend to install ubuntu server Operating system/ Centos for your load balanced server. Here in this article I am mentioning the procedure based on ubuntu.

2.2 Web Servers Node

You may need a minimum of two webservers or multiple of 2, beacuse I am configuring GlusterFS between these webservers for file sharing. GlusterFS is one of the top cluster file system which is built on ext3. With 4 webservers you can configure a RAID10 like GlusterFs file system. That mean your cluster will work if 50% of node go down. It have automatic mirroring and scaling capacity. So there is no need to sync your website / openx contents regularly.

You can chose centos/ubuntu Os as operating system in webserver nodes. If you going to install cPanel then you can only use apache as webservers. Also remember the webservers must need same type of hardware configurations.

2.3 Database Server Node

As it is a single cluster we only use one database sever for Mysql. I recommend to use a bigger configuration of for this server as follows,

  • Processor -Dual Quad core AMD/ Xeon
  • RAM – 12 GB
  • HDD – SAS RAID 10

Again Use Centos as operating system in this server

3. Install and Configure Load Balancer

Please see the picture , the top one is load balance. Let us use the same IP as in this example. Download the latest stable version of Nginx from here .I used nginx-0.7.62.tar.gz . Please proceed as follows.

# wget -c http://sysoev.ru/nginx/nginx-0.7.62.tar.gz
# tar -xzf nginx-0.7.62.tar.gz
# cd nginx-0.7.62/
# ./configure --prefix=/opt/nginx
# make
# make install

Please resolve the dependencies before make.Now we installed Nginx here. It is a best webserver eventhough we can use it as load balanced proxy. The Nginx configuration file is /opt/nginx/conf/nginx.conf . Add the following contents to /opt/nginx/conf/nginx.conf

user  nobody;
worker_processes  5;

error_log  logs/error.log;
pid        logs/nginx.pid;

events {
    worker_connections  4096;

http {
    include     mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  logs/access.log  main;

    sendfile        on;
    tcp_nopush     on;
    keepalive_timeout  65;

    #gzip  on;

        upstream my_openx_site {
        server weight=5;  # this is your webserver www1
        server weight=5;  # this is your web server www2

        server {
                 listen 80;
                server_name localhost;
                location / {
                         proxy_pass http://my_openx_site;


The above configuration have 5 worker processor and can handle 4096 requests per second. If you need more connections increase the limits.
Now add a user and group

# useradd nobody
# groupadd nobody

Now give suitable permission for log folders.

# chown -R nobody.nobody  /opt/nginx/logs/

Now we need to create a startup script. I have done some modification for the initscript as follows. Remember this is for ubuntu. Please copy the following contents to /etc/init.d/nginx

#! /bin/sh
# Provides:          nginx
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: nginx init.d script for Ubuntu 8.10 and lesser versions.
# Description:       nginx init.d script for Ubuntu 8.10 and lesser versions.
# nginx - this script, which starts and stops the nginx daemon for ubuntu.
# description:  Nginx is an HTTP(S) server, HTTP(S) reverse \
#               proxy and IMAP/POP3 proxy server.  This \
#               script will manage the initiation of the \
#               server and its process state.
# processname: nginx
# config:      /opt/nginx/conf/nginx.conf
# pidfile:     /opt/nginx/logs/nginx.pid
# Provides:    nginx

# Notes: nginx init.d script for Ubuntu 8.10 and lesser versions.
. /lib/lsb/init-functions                                                                                                                                                                                                         

#                               Consts

DESCRIPTION="Nginx Server..."                                                                                                                                                                                                     

PS=$NAME                                #the process, which happens to be the NAME
PIDFILE=$NAME.pid                       #pid file
RUNAS=root                              #user to run as                                                                                                                                                                           

SCRIPT_OK=0                             #ala error codes
SCRIPT_ERROR=1                          #ala error codes
TRUE=1                                  #boolean
FALSE=0                                 #boolean                                                                                                                                                                                  


#                               Simple Tests

#test if nginx is a file and executable
test -x $DAEMON || exit 0                                                                                                                                                                                                         

# Include nginx defaults if available
if [ -f /etc/default/nginx ] ; then
        . /etc/default/nginx

#set exit condition
#set -e                                                                                                                                                                                                                           

#                               Functions

configtest() {
        $DAEMON -t -c $NGINX_CONF_FILE

getPSCount() {
        return `pgrep -f $PS | wc -l`


        if [ $PID -gt 0 ]; then
                return 1
                return 0


        if [ "${isAlive}" -eq $TRUE ]; then
                echo "$NAME found running with processes:  `pidof $PS`"
                echo "$NAME is NOT running."


        if [ -f $PIDSPATH/$NAME.pid ]; then
                rm $PIDSPATH/$NAME.pid

start() {
        log_daemon_msg "Starting $DESCRIPTION"                                                                                                                                                                                    


        if [ "${isAlive}" -eq $TRUE ]; then
                log_end_msg $SCRIPT_ERROR
                start-stop-daemon --start --quiet --chuid $RUNAS --pidfile $PIDSPATH/$PIDFILE --exec $DAEMON
                chmod 400 $PIDSPATH/$PIDFILE
                log_end_msg $SCRIPT_OK

stop() {
        log_daemon_msg "Stopping $DESCRIPTION"                                                                                                                                                                                    

        if [ "${isAlive}" -eq $TRUE ]; then
                start-stop-daemon --stop --quiet --pidfile $PIDSPATH/$PIDFILE                                                                                                                                                     


                log_end_msg $SCRIPT_OK
                log_end_msg $SCRIPT_ERROR

reload() {
        configtest || return $?                                                                                                                                                                                                   

        log_daemon_msg "Reloading (via HUP) $DESCRIPTION"                                                                                                                                                                         

        if [ $? -eq $TRUE ]; then
                `killall -HUP $PS` #to be safe                                                                                                                                                                                    

                log_end_msg $SCRIPT_OK
                log_end_msg $SCRIPT_ERROR

terminate() {
        log_daemon_msg "Force terminating (via KILL) $DESCRIPTION"                                                                                                                                                                

        PIDS=`pidof $PS` || true                                                                                                                                                                                                  

        [ -e $PIDSPATH/$PIDFILE ] && PIDS2=`cat $PIDSPATH/$PIDFILE`                                                                                                                                                               

        for i in $PIDS; do
                if [ "$i" = "$PIDS2" ]; then
                        kill $i

        log_end_msg $SCRIPT_OK                                                                                                                                                                                                    


pidof_daemon() {
    PIDS=`pidof $PS` || true


    for i in $PIDS; do
        if [ "$i" = "$PIDS2" ]; then
            return 1
    return 0

case "$1" in
        echo "Usage: $FULLPATH {start|stop|restart|force-reload|status|configtest|terminate}"
        exit 1

exit 0

Now give execute permission to this script

# chmod 755 /etc/init.d/nginx

This is all about Load balancer configuration. You can start the Load balance, before that you may need to build your webservers as described below,

4. Install and Configure Webserver

Now we need to configure our web servers. All request came to Load balancer will be passed to your webserver. You can use lighttpd or apache2.2.x as webserver . I recommend to you lighttpd as webserver , because it can handle very high traffic websites with zero load. Before that we are going to configure gluster fs file system among the webserver. These file system is very scalable and high available.

4.1 File system configuration

If you don’t need a common file system, please skip this step.Let us use the minimal number of webservers for Glusterfs. If you have 4 webservers, it is easy to setup a RAID10 model cluster file system. Here we use two servers.
Download the latest stable version of glusterfs from http://www.gluster.com/ . I here used version glusterfs-2.0.2

# tar -xzf 	 glusterfs-2.0.2.tar.gz
# cd 	glusterfs-2.0.2/
# ./configure
# make
# make install

Now create the configuration files as follows.

# mkdir /etc/glusterfs/
# touch /etc/glusterfs/glusterfsd.vol

The server itself can act as server and client . The GFS server configuration is /etc/glusterfs/glusterfsd.vol . Now add the following contents to this file.

# file: /etc/glusterfs/glusterfsd.vol
volume posix
  type storage/posix
  option directory /data    # this partition is sharing

volume locks
  type features/locks
  subvolumes posix

volume brick
  type performance/io-threads
  option thread-count 8
  subvolumes locks

volume server
  type protocol/server
  option transport-type tcp
  option auth.addr.brick.allow *
  subvolumes brick

Now create the GlusterFS client configuration file /etc/glusterfs/glusterfs-client.vol as follows

# file  /etc/glusterfs/glusterfs-client.vol
volume remote1
  type protocol/client
  option transport-type tcp
  option remote-host
  option remote-subvolume brick
volume remote2
  type protocol/client
  option transport-type tcp
  option remote-host
  option remote-subvolume brick
volume distribute
  type cluster/distribute
  subvolumes remote1 remote2
volume writebehind
  type performance/write-behind
  option window-size 1MB
  subvolumes distribute
volume cache
  type performance/io-cache
  option cache-size 512MB
 subvolumes writebehind

So now we have both client and server configuration for the Glusterfs file system. Here the /data partition is sharing around the webservers. You may need to create same configuration in all webservers.
Now start the glusterfs server

# /etc/init.d/glusterfsd  start

Now mount the file system to /home as follows

# glusterfs -f /etc/glusterfs/glusterfs-client.vol /home

Add the above line to rc.local file so during reboot your file system will mount automatically. So now we have a common files system among the webserver nodes.

4.2 Lighttpd installation

Please note either you install lighttpd as webserver or use apache. If you going to chose apache please jump to next step.
Download the lighty from http://www.lighttpd.net/download I used the latest version.

# wget -c http://www.lighttpd.net/download/lighttpd-1.4.23.tar.gz
# tar -xzf lighttpd-1.4.23.tar.gz
# cd lighttpd-1.4.23/
# ./configure --prefix=/opt/lighttpd --enable-fastcgi  --with-openssl
# make
# make install
# mkdir -p /etc/lighttpd/
# cp doc/lighttpd.conf  /etc/lighttpd/
# cp doc/rc.lighttpd.redhat  /etc/init.d/lighttpd
# chmod 755  /etc/init.d/lighttpd

Now edit the init script /etc/init.d/lighttpd and update the following line as given below,


ow we need to configure lighttpd with php. Please install php as fcgi module. It is easy
Download the latest stable php from http://php.net/ and extract it. Now build it as follows,

# /configure --prefix=/usr/local/php5/  \
	--with-config-file-path=/usr/local/php5/etc \
	 --enable-force-cgi-redirect --enable-fastcgi\
	--with-gd --with-jpeg-dir=/usr/local --with-zlib \
	--with-openssl  --with-mysql
# make
# make install
# cp php.ini-dist  /usr/local/php5/etc/php.ini

Now edit /etc/lighttpd/lighttpd.conf as follows.

server.modules              = (
                               "mod_accesslog" ) 

server.document-root        = "/home/openx/public_html"
server.errorlog             = "/var/log/lighttpd/error.log"
index-file.names            = ( "index.php", "index.html",
                               "index.htm", "default.htm" )
mimetype.assign             = (
  ".pdf"          =>      "application/pdf",
  ".sig"          =>      "application/pgp-signature",
  ".spl"          =>      "application/futuresplash",
  ".class"        =>      "application/octet-stream",
  ".ps"           =>      "application/postscript",
  ".torrent"      =>      "application/x-bittorrent",
  ".dvi"          =>      "application/x-dvi",
  ".gz"           =>      "application/x-gzip",
  ".pac"          =>      "application/x-ns-proxy-autoconfig",
  ".swf"          =>      "application/x-shockwave-flash",
  ".tar.gz"       =>      "application/x-tgz",
  ".tgz"          =>      "application/x-tgz",
  ".tar"          =>      "application/x-tar",
  ".zip"          =>      "application/zip",
  ".mp3"          =>      "audio/mpeg",
  ".m3u"          =>      "audio/x-mpegurl",
  ".wma"          =>      "audio/x-ms-wma",
  ".wax"          =>      "audio/x-ms-wax",
  ".ogg"          =>      "application/ogg",
  ".wav"          =>      "audio/x-wav",
  ".gif"          =>      "image/gif",
  ".jar"          =>      "application/x-java-archive",
  ".jpg"          =>      "image/jpeg",
  ".jpeg"         =>      "image/jpeg",
  ".png"          =>      "image/png",
  ".xbm"          =>      "image/x-xbitmap",
  ".xpm"          =>      "image/x-xpixmap",
  ".xwd"          =>      "image/x-xwindowdump",
  ".css"          =>      "text/css",
  ".html"         =>      "text/html",
  ".htm"          =>      "text/html",
  ".js"           =>      "text/javascript",
  ".asc"          =>      "text/plain",
  ".c"            =>      "text/plain",
  ".cpp"          =>      "text/plain",
  ".log"          =>      "text/plain",
  ".conf"         =>      "text/plain",
  ".text"         =>      "text/plain",
  ".txt"          =>      "text/plain",
  ".dtd"          =>      "text/xml",
  ".xml"          =>      "text/xml",
  ".mpeg"         =>      "video/mpeg",
  ".mpg"          =>      "video/mpeg",
  ".mov"          =>      "video/quicktime",
  ".qt"           =>      "video/quicktime",
  ".avi"          =>      "video/x-msvideo",
  ".asf"          =>      "video/x-ms-asf",
  ".asx"          =>      "video/x-ms-asf",
  ".wmv"          =>      "video/x-ms-wmv",
  ".bz2"          =>      "application/x-bzip",
  ".tbz"          =>      "application/x-bzip-compressed-tar",
  ".tar.bz2"      =>      "application/x-bzip-compressed-tar",
  ""              =>      "application/octet-stream",

accesslog.filename          = "/var/log/lighttpd/access.log"
url.access-deny             = ( "~", ".inc" )
$HTTP["url"] =~ "\.pdf$" {
  server.range-requests = "disable"
static-file.exclude-extensions = ( ".php", ".pl", ".fcgi" )
fastcgi.server = ( ".php" => ((
                     "bin-path" => "/usr/local/php5/bin/php",
                     "socket" => "/tmp/php.socket",
                     "max-procs" => 2,
                     "bin-environment" => (
                       "PHP_FCGI_CHILDREN" => "16",
                       "PHP_FCGI_MAX_REQUESTS" => "10000"
                     "bin-copy-environment" => (
                       "PATH", "SHELL", "USER"
                     "broken-scriptfilename" => "enable"

So the above configuration will handle 10000 requests per children per second. You can adjust the factcgi.server options as you wish. Remember it is good all your webservers have same type configuration.

4.3 Apache installation

if you have cpanel or you are going to use apache2.2.x as webserver, please read my previous article to know how to configure it. Openx Hand Book

5. Install and Configure Database Server

Now you can install your mysql server and configure it.

# yum install mysql-server -y

Edit the my.cnf as follows(Remember it depend on your hardware )

old-passwords = 1
max_connections =2048
max_user_connections = 1024
key_buffer_size = 2048M
myisam_sort_buffer_size = 64M
join_buffer_size = 1M
read_buffer_size = 1M
sort_buffer_size = 2M
table_cache = 4000
thread_cache_size = 384
wait_timeout = 20
connect_timeout = 10
tmp_table_size = 2048M
max_heap_table_size = 512M
max_allowed_packet = 64M
net_buffer_length = 16384
max_connect_errors = 10
thread_concurrency = 16
concurrent_insert = 2
table_lock_wait_timeout = 30
read_rnd_buffer_size = 786432
bulk_insert_buffer_size = 8M
query_cache_limit = 7M
query_cache_size = 64M
query_cache_type = 1
query_prealloc_size = 262144
query_alloc_block_size = 65536
transaction_alloc_block_size = 8192
transaction_prealloc_size = 4096
max_write_lock_count = 16
long_query_time = 5

open_files_limit = 8192

max_allowed_packet = 16M

key_buffer = 384M
sort_buffer = 384M
read_buffer = 256M
write_buffer = 256M

Now restart mysql server and create a database as follows

# mysqladmin create openx_db

Now go to mysql command prompt and create a user and password as follows

#mysql>grant all privileges on openx_db.* to 'openx_user'@'%' identified by 'VERYSTRONGPASSWORD';

So now for your openx configuration use host as your mysql serve IP(here and database user and password same as above.

6. Optimization

Now it is time to optimize your servers. Please read my Openx Handbook for optimizations ,

Appendix-A About The Author

My Name : Sherin A
My Web Site : http://www.sherin.co.in/ If you wan’t my designation , you can call me, System Engineer , Security Expert , Software Engineer or a FOSS member.
About me :
1) Founder of vcPanel ( Virtual Private Server Control panel )
2) Founder of FOSS award winner project ffmpegistaller )
3) Founder of FossBlog ( A Free and Open Source Software Blog
My relation with Adds : I am here with adds since 2003. Now providing Openx services for companies US , Canad, UK, Australia, Japan , India ,Germany, Croatia and Russia. Contact Me : All my contacts are available here or send email to me sherinmon[at]gmail[dot]com

Appendix-B License

This article is licensed under Creative Commons Attribution-Noncommercial 2.5 India It means you can share and redistribute it , but give a link back to this original document, because sometimes I will add more tips to this document.

Openx performance boosting with memcached

I was testing memcached in one of my cluster. It is seems to be very useful to increase performance. As it is “Memcached is an in-memory key-value store for small chunks of arbitrary data (strings, objects) from results of database calls, API calls, or page rendering.” , Read more about http://memcached.org/, and see who all are using memcached.

But the main thing is your application need memcached support otherwise it won’t work.

So Openx have a plugin for memcached support. This will help your openx faster delivery via delivery cache. To enable this plugin go to Global Settings > Banner Delivery Settings to choose memcached caching of banners. Don’t enable it if you are not installing the following packages.

Before enabling this plugin you must need to install a perfect memcached server in your openx server. So please proceed the following instructions.

Install memcached server

Download the memcached server from http://memcached.org/

 # wget -c  http://memcached.googlecode.com/files/memcached-1.4.5.tar.gz
 # tar -xzf  memcached-1.4.5.tar.gz
 # cd memcached-1.4.5/
 # yum -y install libevent libevent-devel
 # ./configure --prefix=/opt/memcached
 # make
 # make install

Now the installation finished. Let us use the following command to start memcached .

#  /opt/memcached/bin/memcached  -u nobody -d -m 128 -l -p 11211

In the above command memcached will start as a daemon and listen on port 11211 on . Here -m 128 means the amount of memory it can use, here 128 MB of RAM.
So let us create an init script for start/stop of memcached. /etc/init.d/memcached

# Memcached        This shell script takes care of starting and stopping
#               Memcached.
# chkconfig: 2345 95 55
# description: memcached is a memory caching server

# Source function library.
if [ -f /etc/init.d/functions ]; then
  . /etc/init.d/functions
elif [ -f /etc/rc.d/init.d/functions ]; then
  . /etc/rc.d/init.d/functions
  echo "Could not find functions file, your system may be broken"
  exit 1

# Source networking configuration.
if [ -f "/etc/sysconfig/network" ] ; then
        . /etc/sysconfig/network

# Check that networking is up.
[ ${NETWORKING} = "no" ] && exit 0

[ -f /opt/memcached/bin/memcached  ] || exit 0

# See how we were called.
case "$1" in
        # Start daemons.
        echo -n "Starting memcached: "
        /opt/memcached/bin/memcached  -u nobody -d -m 128 -l -p 11211
        touch /var/lock/subsys/memcached
        # Stop daemons.
        echo -n "Shutting down bandmin: "
        pkill -9 memcached
	pkill -9 memcached
        rm -f /var/lock/subsys/memcached
        echo "Usage: memcached {start|stop}"
        exit 1
exit 0

Now give execute permission to init script as follows,

# chmod 755 /etc/init.d/memcached

If you need to start this server during reboot , please add the following line to /etc/rc.local

# /etc/init.d/memcached  start

So our server is ready. Now we need ton install the php-pecl memcached extension. Otherwise your application won’t work,

Install php-pecl memcached

Download the latest stable memcached from http://pecl.php.net/package/memcache

# wget -c http://pecl.php.net/get/memcache-2.2.5.tgz
# tar -xzf  memcache-2.2.5.tgz
# cd memcache-2.2.5/
# phpize
# ./configure
# make
# make install

Now restart apache and create a phpinfo page and test whether the memcache options is showing or not. If it is there go to Openx admin and enable the plugin.

Installing mod_limitipconn in cPanel server

This apache module will limit number of IP connections from a particular IP to a specific domain or files. You can see the project home page from http://dominia.org/djao/limitipconn2.html . This module have apache 1.3 , 2.x and 2.2.x packages.

wget http://dominia.org/djao/limit/mod_limitipconn-0.23.tar.bz2

tar -xjf mod_limitipconn-0.23.tar.bz2

cd mod_limitipconn-0.23/

/usr/local/apache/bin/apxs -cia mod_limitipconn.c


cat >> /usr/local/apache/conf/mod_limitipconn.conf << EOF

LoadModule limitipconn_module modules/mod_limitipconn.so

ExtendedStatus On

<IfModule mod_limitipconn.c>

# Set a server-wide limit of 10 simultaneous downloads per IP,

# no matter what.

MaxConnPerIP 10

<Location /somewhere>

# This section affects all files under http://your.server/somewhere

MaxConnPerIP 3

# exempting images from the connection limit is often a good

# idea if your web page has lots of inline images, since these

# pages often generate a flurry of concurrent image requests

NoIPLimit image/*


<Directory /home/*/public_html>

# This section affects all files under /home/*/public_html

MaxConnPerIP 1

# In this case, all MIME types other than audio/mpeg and video*

# are exempt from the limit check

OnlyIPLimit audio/mpeg video



Now edit the file /usr/local/apache/conf/includes/pre_main_global.conf and add the following lines

Include “/usr/local/apache/conf/mod_limitipconn.conf”

Now restart apache
You can check whether the module loaded or not using the following command.
/usr/local/apache/bin/httpd -M | grep limitipconn_module

Wireless internet connection sharing

If you have a wireless internet device connected to your laptop, then you can use your laptop as an internet gate way in your LAN . Other computers can access internet through your laptop. If your internet is fast you can run a small office over that wify connection.

Let me explain how it possible.

So you need two NIC’s in your computer and running Linux operating system.

Your Laptop configuration:

wlan0 -> This will be connected to public internet and you can access internet from your laptop
eth0 -> This will connect to your lan or switch , let us assign an ip for it

Now perform the following commands.

# echo 1 > /proc/sys/net/ipv4/ip_forward

# /sbin/iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE

# /sbin/iptables -A FORWARD -i wlan0 -o eth0 -m state –state RELATED,ESTABLISHED -j ACCEPT

# /sbin/iptables -A FORWARD -i eth0 -o wlan0 -j ACCEPT
Now go to nearest computer and configure an ip address on range , make sure to use gateway ip . You can also use public name servers and

Now access internet and surf the world. Enjoy it. If you need to use this after a reboot , make sure the above iptable rules must be saved.

How to configure wireless lan in Lenovo s10 or s20 in Ubuntu

It is really easy to configure wireless lan card in your lenovo s10. Its default driver won’t work properly in Linux. So do the following command.
# apt-get –reinstall install bcmwl-kernel-source
Now go to System -> Administration -> Hardware driver , here you can see Brodcom STA wireless driver. Reboot your laptop and connect to wireless.

Some usefull urls,

Installing mod_geoip on Apache 2.2

1) Downlaod the latets GEOIP package from http://geolite.maxmind.com/download/geoip/api/c/ and install it

# wget -c  http://geolite.maxmind.com/download/geoip/api/c/GeoIP-1.4.6.tar.gz
# tar -xzf GeoIP-1.4.6.tar.gz
# cd GeoIP-1.4.6/
# ./configure
# make
# make install

2) Download and install latest mod_geoip2 from http://geolite.maxmind.com/download/geoip/api/mod_geoip2/

# wget -c  http://geolite.maxmind.com/download/geoip/api/mod_geoip2/mod_geoip2_1.2.5.tar.gz
# tar -xzf  mod_geoip2_1.2.5.tar.gz
# cd mod_geoip2_1.2.5/
# /usr/local/apache/bin/apxs -lGeoIP  -cia mod_geoip.c

3) Restart apache