It is highly recommended to increase the following limits in /etc/php.ini so that uploads through PHP will work as expected.

# php -r"phpinfo();" | grep upload
file_uploads => On => On
max_file_uploads => 20 => 20
upload_max_filesize => 2M => 2M

Restart http deamon usually using the command:
/etc/init.d/httpd restart

The global array $_COOKIE is used to retrieve the cookie value for subsequent page requests. Like...

<?php
$visits = 1;
if (isset($_COOKIE["visits"])) {
$visits = (int)$_COOKIE["visits"];
}
setcookie("visits", $visits + 1, time() + (60 * 60 * 24 * 30));
echo "You have visited this page $visits time(s).";

We can use logger command in a crontab.

59 23 * * * /home/john/bin/backup.sh > /home/john/logs/backup.log | logger -t backup 2>&1

It is also possible to skip the standard error and let mailto send you the errors:

MAILTO=me@domain.com

Innodb tables queries based on information_schema may be slower. In order to improve the performance, we need to disable metadata updates.

set global innodb_stats_on_metadata = 0;

http://dev.mysql.com/doc/refman/5.5/en/innodb-parameters.html#sysvar_innodb_stats_on_metadata

We can not scroll up or down while working in screen mode. Press Ctrl-a, Esc to enter copy mode, then use standard navigation keys. Adding the following to ~/.screenrc will solve this issue.
termcapinfo xterm|xterms|xs|rxvt ti@:te@

or add this to /etc/screenrc
defscrollback 1024

hardstatus on
hardstatus alwayslastline
hardstatus string "%{.bW}%-w%{.rW}%n %t%{-}%+w %=%{..G} %H %{..Y} %m/%d %C%a "

As a quick tip, name your screen windows using Ctrl-a A

Enabling superstars in gmail Settings gives you 11 more ways to star your messages. You can use star names, like "has:yellow-star" or "has:red-bang". In Settings, just hover your mouse over each superstar icon to find the star names.

# sysctl vm.swappiness
vm.swappiness = 60

With that setting the Linux kernel feels encouraged to use the available swap. On a dedicated MySQL server, swappiness should be set to zero to discourage kernel from swapping out application memory.

# sysctl -w vm.swappiness=0
vm.swappiness = 0

This changes the runtime setting. To allow the change to survive system restarts, just add vm.swappiness=0 as a separate line into /etc/sysctl.conf

We need to change DocumentRoot variable in the configuration file.

vi /etc/httpd/conf/httpd.conf

DocumentRoot /mnt
serverName rredis.mycompany.com
ErrorLog /var/log/httpd/error_log

Make sure serverName does not conflict and ErrorLog path exist.

Set up git:

yum install git-core
cd ~/.ssh
ssh-keygen -t rsa -C "shantanu.oak@gmail.com"

Contents of the file "id_rsa.pub" should be copied to gitHub site.
On the GitHub site Click “Account Settings” > Click “SSH Public Keys” > Click “Add another public key”

This will allow passwordless access to github site:
ssh -T git@github.com
_____

Global setup:

git config --global user.name "Shantanu Oak"
git config --global user.email shantanu.oak@gmail.com
_____

Next steps:

mkdir syllabalize_unicode
cd syllabalize_unicode
git init
touch README
git add README
git commit -m 'first commit'
git remote add origin git@github.com:shantanuo/syllabalize_unicode.git
git push -u origin master
_____

Existing Git Repo?

cd existing_git_repo
git remote add origin git@github.com:shantanuo/syllabalize_unicode.git
git push -u origin master
_____

clone (download) the source
git clone git@github.com:ahiguti/HandlerSocket-Plugin-for-MySQL.git
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Install MySQL

mkdir download
cd download
wget http://files.directadmin.com/services/all/mysql/64-bit/5.5.20/MySQL-client-5.5.20-1.linux2.6.x86_64.rpm
wget http://files.directadmin.com/services/all/mysql/64-bit/5.5.20/MySQL-devel-5.5.20-1.linux2.6.x86_64.rpm
wget http://files.directadmin.com/services/all/mysql/64-bit/5.5.20/MySQL-server-5.5.20-1.linux2.6.x86_64.rpm
wget http://files.directadmin.com/services/all/mysql/64-bit/5.5.20/MySQL-shared-5.5.20-1.linux2.6.x86_64.rpm

The commands are as follows:

rpm -iUh *

After installing mysql shared compact library, this was working as expected

wget ftp://ftp.isu.edu.tw/pub/Unix/Database/MySQL/Downloads/MySQL-5.5/MySQL-shared-compat-5.5.24-1.el6.x86_64.rpm
rpm -ihv MySQL-shared-compat-5.5.24-1.el6.x86_64.rpm
yum install php-mysql --skip-broken

_____

Here is how it can be achieved using remi or epel

/usr/bin/wget http://rpms.famillecollet.com/enterprise/remi-release-6.rpm
/bin/rpm -Uvh *.rpm
/usr/bin/yum install --enablerepo=remi mysql-server.x86_64*

Using epel:

wget http://download.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm
rpm -Uvh epel-release-5-4.noarch.rpm
yum install python26

Tunneling an ssh connection through an ssh connection is completely lawful, but you need to pick unused ports for your forwarding listeners.

ssh user@100.100.100.100 -L 2201:192.168.25.100:22

then
ssh localhost -p 2201

You should end up on server B (unless something's already bound to local:2201, in which case, pick another port).
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There are times when you need to connect to a remote server through some other server. You can skip logging to an intermediate server and connect directly to remote server using SSH like this...

ssh -t -t root@192.168.1.1 "ssh -i /root/remote_server.pem ec2-1-2-3-4.compute-1.amazonaws.com"