Walk Through The Cloud

Swift Shell / Swift Console

noreply@blogger.com (Unknown) — Wed, 17 Dec 2014 16:16:00 +0000

Very much like Python, including its syntax, Swift programming language actually has a shell. Isn't that cool?

From your terminal, type:

# xcrun swift

You will then see

Welcome to Swift! Type :help for assistance.
1>

Enjoy!

Install MongooseIM on Ubuntu

noreply@blogger.com (Unknown) — Thu, 18 Sep 2014 15:02:00 +0000

Ever wondered what awesome technology is used behind WhatsApp which was sold at $10B? It's MongooseIM. And here's how to get you started using it, in Ubuntu..

Install the Pre-Built Package:

wget http://packages.erlang-solutions.com/site/esl/mongooseim/FLAVOUR_1_main/mongooseim_1.4.0-1~ubuntu~trusty_amd64.deb

dpkg -i mongooseim_1.4.0-1~ubuntu~trusty_amd64.deb

Configure it

cd /usr/lib/mongooseim/etc
vim ejabberd.cfg

Run it

mongooseimctl live

Linux: Deleted a File and Its NOT Freeing Up Space?

noreply@blogger.com (Unknown) — Mon, 30 Jun 2014 14:03:00 +0000

There is only one reason for it - the file is held by a process.

To fix the issue:

1) Find which process is holding it.

Check open files and return the process using an unlinked file (deleted file)
# lsof +L1

2) Kill the process

# kill -9 <pid>

For a graceful kill but can/may take a while.

# kill -15 <pid>

PayPal: You must specify valid values for the A3, P3, and T3 parameters

noreply@blogger.com (Unknown) — Fri, 30 May 2014 19:54:00 +0000

When you the error "You must specify valid values for the A3, P3, and T3 parameters" it means that the values you sent to PayPal are invalid.

It could mean that,

1) A3 is not a number
2) P3 is beyond the acceptable limits
3) T3 is not valid.

Usually, the problem is a combination of P3 and T3 issue.

In my case, it was sending more than 24 mos for P3. The solution is to convert T3=M to T3=Y and change the P3 to rounded up years, so P3=3. This solve the issue. I wasn't able to find any documentation associated with the acceptable ranges and user inputs to these 3 required parameters for integration recurring payment button.

Install Jenkins on Ubuntu/Debian

noreply@blogger.com (Unknown) — Mon, 19 May 2014 06:33:00 +0000

If you wish to install Jenkins (fork of Hudson, maintained by original developers), do the following:

sudo -i

wget -q -O - http://pkg.jenkins-ci.org/debian/jenkins-ci.org.key | sudo apt-key add -

sh -c 'echo deb http://pkg.jenkins-ci.org/debian binary/ > /etc/apt/sources.list.d/jenkins.list'
apt-get update
apt-get install jenkins


Note: make sure JAVA is installed.

Install ElasticSearch 1.0.x on Ubuntu/Debian

noreply@blogger.com (Unknown) — Mon, 19 May 2014 05:17:00 +0000

ES released an apt-get repo for ElasticSearch. It is the recommended package-driven deployment.

sudo -i
apt-get install openjdk-7-jre-headless -y
wget -O - http://packages.elasticsearch.org/GPG-KEY-elasticsearch | apt-key add -

vim /etc/apt/sources.list

#Append the following, then save

deb http://packages.elasticsearch.org/elasticsearch/1.0/debian stable main



apt-get update
apt-get install elasticsearch


service elasticsearch start

Yum Install ElasticSearch 1.x

noreply@blogger.com (Unknown) — Thu, 15 May 2014 19:58:00 +0000

Note: Works for CentOS/RHEL/Fedora.

rpm --import http://packages.elasticsearch.org/GPG-KEY-elasticsearch

vim /etc/yum.repos.d/elasticsearch.repo

[elasticsearch-1.0]
name=Elasticsearch repository for 1.0.x packages
baseurl=http://packages.elasticsearch.org/elasticsearch/1.0/centos
gpgcheck=1
gpgkey=http://packages.elasticsearch.org/GPG-KEY-elasticsearch
enabled=1

yum update
yum install java-1.7.0-openjdk.i686 -y
yum install elasticsearch

Start ElasticSearch

/etc/init.d/elasticsearch start

If you are wondering where the data directory is for this installations steps, it is stored at:

/var/lib/elasticsearch/elasticsearch

The Idiot PHP Developer's Creed

noreply@blogger.com (Unknown) — Mon, 24 Mar 2014 11:08:00 +0000

I am a PHP Developer and this is my creed.

PHP is the best programming language, ever.

I don't need no framework or library, my native code is light and fast.

I can code anywhere, as long as it works, it is correct.

I don't need OOP, best practices, design patterns, software architecture and all that crap. They slow me down.

I rate myself 9 out of 10 because I memorised most of the native functions or pretend to be.

I rate myself 10 out of 10 because I can build a shopping cart website within 3 days or because of whatever.

I prefer the use of arrays because they are better than objects.

I believe project managers, business analysts and QA are useless.

I don't have to test my work, somebody else should.

I don't have to look at the error logs, my code is perfect.

I copy-paste code that the first page of my Google search results which seems cool and working.

I don't need to understand what I copy-pasted.

I claim the copy-pasted code as my own and grin with pride.

If my code CANNOT be understood, then I am super awesome.

The hardest thing I did is to build a website using WordPress.

I don't need Math, Statistics, Science, or Business to level up in my field. I can do anything with PHP.

I develop PHP using WAMP and use a Windows-based IDE while production deployment is in Linux/Unix.

I use get_browser() function to detect user agent.

I use static methods, globals, constants every chance I get.

I only need if-then-else to implement logic and algorithm. The longer, the better. I love spaghetti.

I loop through an external resource call.

It takes an FTP uploader to deploy my code.

I have hardcoded stuff everywhere.

I don't need to document my code or put doc blocks for that matter. It takes away precious development time.

(to be continued)

Kill Sleeping MySQL Processes using Quick PHP Script

noreply@blogger.com (Unknown) — Tue, 18 Mar 2014 20:31:00 +0000

Our server was getting swamped with too many sleeping connections causing "too many connections" error. During production hours, manually killing them isn't an option, there are just too many and MySQL nor MariaDB doesn't have a native tool for it. I needed it fast, so I wrote a quick PHP code which can then be run every minute as a CRON job.

Here's the code:

<?php
mysql_connect('yourhost', 'username', 'password');
$res = mysql_query("SHOW FULL PROCESSLIST");
while ($row=mysql_fetch_array($res)) {
  $pid=$row["Id"];
  if ($row['Command']=='Sleep') {
      if ($row["Time"] > 3 ) { //any sleeping process more than 3 secs
         $sql="KILL $pid";
         echo "\n$sql"; //added for log file
         mysql_query($sql);
      }
  }
}

You can then save this to a file mysqlkillsleeping.php, and add it as a CRON job running every minute

vim /etc/crontab

*/1 * * * * root php /path/of/mysqlkillsleeping.php 2>&1 >> /var/log/mysqlsleep.log

Yum Install ImageMagick

noreply@blogger.com (Unknown) — Fri, 14 Feb 2014 05:18:00 +0000

ImageMagick is an image manipulation application which supports most of the standard image formats. It is also a very powerful command line tool for batch processing images. If you wish to use it in CentOS or Fedora, just install it using YUM package manager.

# yum install ImageMagick

How to Add 3rd Party Libraries to Zend Framework 2

noreply@blogger.com (Unknown) — Thu, 13 Feb 2014 20:26:00 +0000

You can easily add other libraries to Zend Framework 2 whether they are your custom libraries, 3rd party libraries or standard packages from packagist.org or Github. However, the explanation and method on how to add and autoload them properly to the software architecture was not easy find, at least for me.

Since you're here, I've made it a tad easier for you and itemised the use-cases.

1) Adding custom libraries which are GLOBAL to your application

Edit composer.json and add within the closure,

"autoload": {
"psr-0": {"MyLibrary\\":"vendor/my/library/path"}
}

Then run "composer update" from the CLI under your application root directory. This will add an entry to your <APPLICATION_PATH>/vendor/composer/autoload_namespaces.php.

Alternatively, you can directly add an entry to it.

return array(
'Zend\\' => array($vendorDir . '/zendframework/zendframework/library'),
'MyLibrary\\' => array($vendorDir . '/my/library/path'),
);

2) Adding custom libraries specific to a module

Edit <APPLICATION_PATH>/module/Yourmodule/Module.php

public function getAutoloaderConfig()
{
return array(
'Zend\Loader\ClassMapAutoloader' => array(
__DIR__ . '/autoload_classmap.php',
),
'Zend\Loader\StandardAutoloader' => array(
'namespaces' => array(
__NAMESPACE__ => __DIR__ . '/src/' . __NAMESPACE__,
'YourLibrary' => __DIR__ . '/../../vendor/your/Library' <<---- add something similar to the following
)
),
);
}

3) Adding standard / accepted libraries from packagist.org or any repositories which supports composer

Edit composer.json and add the following entry,

"require": {
"php": ">=5.3.3",
"zendframework/zendframework": "2.2.*",
"package/name": ">=1.0" <<--- add something similar to the following
},

And if you want to include the packages required for the development of the packages like running tests etc. you can add/modify require-dev as well.

"require-dev": {
"package/name": ">=1.0" <<--- add something similar to the following
},

For adding additional repositories other than packagist.org, get more info here.

WARNING: Zend Framework 2, even the earlier version, is sensitive with the usage of underscores. So, if you don't want unnecessary complications due to the autoloading quirks, avoid them. Anyway, it is why namespaces are introduced in the first place.

How to Make Your Module Default in Zend Framework 2

noreply@blogger.com (Unknown) — Mon, 27 Jan 2014 12:27:00 +0000

Just make sure you have the proper route to slash (/) and the first in the alphabetical hierarchy of the other modules.

/module/modulename/config/module.config.php

'router' => array(
'routes' => array(
'home' => array(
'type' => 'Zend\Mvc\Router\Http\Literal',
'options' => array(
'route' => '/',
'defaults' => array(
'controller' => 'Account\Controller\Index',
'action' => 'index',
),
),
),
),
);

How To Set-up ZendFramework 2 for Developers from Scratch

noreply@blogger.com (Unknown) — Fri, 24 Jan 2014 09:58:00 +0000

Here are a few easy steps to bootstrap your development using Zend Framework 2.x. This assumes that you are using PHP 5.3.x or higher on a *nix machine. Was tested to work on Fedora and CentOS.

1) Install composer

(make sure you are a root user)
# sudo -i
# curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/src/
# mv /usr/local/src/composer.phar /usr/local/bin/composer

# chmod +x /usr/local/bin/composer

2) Download and install ZendFramework Skeletion Application

# composer create-project --repository-url="http://packages.zendframework.com" zendframework/skeleton-application /path/to/install/skeleton/app dev-master

3) Create your Apache virtual host (or any web server for that matter which you can easily find tutorials - search google: configure NGINX virtual host).

Add your vhost configuration file by copying the sample virtual host configuration to a vhost file. The file path may vary depending on your OS and filesystem setup.

# vim /etc/httpd/conf.d/vhosts/local.dev.ulaptech.conf

<VirtualHost *:80>
ServerName local.dev.ulaptech.com
DocumentRoot /path/to/install/skeleton/app/public
ServerAdmin root@localhost
ErrorLog logs/dev.ulaptech.com-error_log
CustomLog logs/dev.ulaptech.com-access_log common
SetEnv APPLICATION_ENV local
<Directory /path/to/install/skeleton/app>
Order deny,allow
Allowoverride All
</Directory>
</VirtualHost>
# /etc/init.d/httpd configtest
If everything is in order, restart Apache
# /etc/init.d/httpd restart

4) Add entry to your local host file, so you can check the skeleton App from your browser.

# vim /etc/hosts
127.0.0.1 local.dev.ulaptech.com
<Enter.your.local.IP> local.dev.ulaptech.com

5) Check your running ZF2 skeleton Application from your browser.

6) Add your setup to you favorite SCM tool (SVN or Git)

# cd /path/to/install/skeleton/app
SVN: svn import https://your.svn.host/your/trunk -m "importing ulaptech files for the first time"
Git: git init; git commit -m "initial commit"; git add remote origin https://your.git.host/your/trunk.git; git push origin master;

7) Point your skeleton app to your favorite PHP IDE/Editor - PhpStorm, NetBeans, SublimeText, Eclipse etc.

8) Start coding :)

PHP: Detect Credit Card Type and Simplify Payment Form

noreply@blogger.com (Unknown) — Wed, 18 Dec 2013 13:38:00 +0000

Simplifying forms is the way to go to improve the payment experience. It's pretty much becoming the standard to not ask the credit card type anymore.

Here's a clean way to do it in PHP 5.4+.
Note: To work with PHP 5.3 below, change square brackets with "array()".

function getCreditCardType($str, $format = 'string')
    {
        if (empty($str)) {
            return false;
        }

        $matchingPatterns = [
            'visa' => '/^4[0-9]{12}(?:[0-9]{3})?$/',
            'mastercard' => '/^5[1-5][0-9]{14}$/',
            'amex' => '/^3[47][0-9]{13}$/',
            'diners' => '/^3(?:0[0-5]|[68][0-9])[0-9]{11}$/',
            'discover' => '/^6(?:011|5[0-9]{2})[0-9]{12}$/',
            'jcb' => '/^(?:2131|1800|35\d{3})\d{11}$/',
            'any' => '/^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|6(?:011|5[0-9][0-9])[0-9]{12}|3[47][0-9]{13}|3(?:0[0-5]|[68][0-9])[0-9]{11}|(?:2131|1800|35\d{3})\d{11})$/'
        ];

        $ctr = 1;
        foreach ($matchingPatterns as $key=>$pattern) {
            if (preg_match($pattern, $str)) {
                return $format == 'string' ? $key : $ctr;
            }
            $ctr++;
        }
    }

You can further enhance the experience on the UI part by adding a javascript equivalent of the above function and have it dynamically change credit card logos indicating credit card type dynamically as people type their credit card number.

This implementation was based on an answer found here. Fyi, Google, Github etc are using the same method for their payment forms and a lot more are doing so as the day pass by to improve their conversions.

PHP: posix_getpid() is Undefined

noreply@blogger.com (Unknown) — Thu, 12 Dec 2013 22:55:00 +0000

With the most recent versions of Fedora / CentOS, the function posix_getpid() maybe undefined because it has been moved to php-process module.

To fix:

yum install php-process

Or,

simply use getmypid() as alternative.

Yum Install Percona Toolkit (Maatkit)

noreply@blogger.com (Unknown) — Wed, 06 Nov 2013 13:31:00 +0000

You need the some tools for MySQL / MariaDb administration and Percona Toolkit (formerly Maatkit) is just the right tools for you. Here's how to install them,

1) Install the Repo.

For 64-bit: rpm -Uhv http://www.percona.com/downloads/percona-release/percona-release-0.0-1.x86_64.rpm

For 32-bit: rpm -Uhv http://www.percona.com/downloads/percona-release/percona-release-0.0-1.i386.rpm

2) Yum Install Percona Toolkit.

yum install percona-toolkit-2.2.5-2.noarch

3) Then use the tools as it is.

pt-agent
pt-duplicate-key-checker
pt-index-usage
pt-pmp
pt-slave-restart
pt-upgrade
pt-align
pt-fifo-split
pt-ioprofile
pt-query-digest
pt-stalk
pt-variable-advisor
pt-archiver
pt-find
pt-kill
pt-show-grants
pt-summary
pt-visual-explain
pt-config-diff
pt-fingerprint
pt-mext
pt-sift
pt-table-checksum
ptar
pt-deadlock-logger
pt-fk-error-logger
pt-mysql-summary
pt-slave-delay
pt-table-sync
ptardiff
pt-diskstats
pt-heartbeat
pt-online-schema-change
pt-slave-find
pt-table-usage
ptx

Usage info here and here.

How To Redirect From the Bootstrap in Zend Framework 1x

noreply@blogger.com (Unknown) — Sat, 19 Oct 2013 19:23:00 +0000

If you need to redirect from the Bootrstrap context, you can do:

$front = Zend_Controller_Front::getInstance();
$response = new Zend_Controller_Response_Http();
$response->setRedirect(Zend_Registry::get('config')->et->core->url . '/' . $args[1]);
$front->setResponse($response);

The most simplistic, basic PHP approach would be:

header("Location: " . Zend_Registry::get('config')->et->core->url . '/' . $args[1]);
ob_end_clean();
ob_end_flush();

Note: The ob_* functions are to terminate the output buffering routine of Zend Framework and start sending headers to the browser.

Or,

header("Location: " . Zend_Registry::get('config')->et->core->url . '/' . $args[1]);
exit;

Note: the "exit" will force Zend Framework to reach the EOF (end of file) and thus start sending the headers to the browser.

Whichever method you choose would work. Re: their advantages, convention-wise the first one is the most ideal, the fastest however would be the last.

PHP: XCache Don't and Won't Work on CLI

noreply@blogger.com (Unknown) — Sun, 06 Oct 2013 02:49:00 +0000

The makers of XCache, opcode cacher of PHP, decided not to support it on CLI. This is a design decision more than a defect. Here's more info http://xcache.lighttpd.net/ticket/317.

It's not the end of the world though, there are still options like Memcache, IPCS or APC that you can use for such. Also, so your CLI doesn't show any error messages, prevent it from being used by checking it's SAPI name.

if (function_exists('xcache_get') && php_sapi_name() != 'cli') {
//xcache_get
//xcache_set
}

Tracking Email Perfomance from Multiple ESPs Using Google Analytics

noreply@blogger.com (Unknown) — Thu, 19 Sep 2013 09:48:00 +0000

In order to diversify the sending and make it more cost effective for us. We are now using 3 email service providers. There are cost and technical advantages/disadvantages for each but generally, we managed to lower our cost by half and our deliverability by 25%. Now the question of how effective it is remain, answer the question - how many converted from which ESP (email service provider)?.

The solution, Google Analytics custom campaigns (https://support.google.com/analytics/answer/1033863?hl=en&ref_topic=1032998). Using it, we populated the links to our landing pages with utm_source, utm_medium and utm_campaign

utm_source

We added the ESP descriptor here - i.e aws, mailgun, mailjet

utm_medium

populated with 'email'

utm_campaign

We added the campaign name / ID here i.e product code, newsletter type

And optionally from time-to-time we add a value to utm_content, which can contain a variation of the same campaign name / ID.

The resulting landing page URL became:

http://yourdomain.com/landingpage.html?utm_source=aws&utm_medium=email&utm_campaign=newsletterX

In Google Analytics, we were now able to see under our Goal conversion dashboard (Conversions->Goals->Overview) a filter of our source/medium namely - aws/email, <other sources>/email which answered the question above - how many converted from which ESP?.

I just got reminded by Edison - Am I close?

noreply@blogger.com (Unknown) — Sat, 14 Sep 2013 22:07:00 +0000

Today is my first non-technical post. For some reason, two of the best quotes of Edison that I have known so far showed up in my face without intentionally looking for them. Here they are.

The first one I saw while browsing IdeaSpace,a startup incubator / investor.

"Vision without execution is hallucination"

- Thomas Edison

The second one, a defunct calling card of a former partner / colleague.

"Many of life's failures are experienced by people who did not realise how close they were to success when they gave up"

- Thomas Edison

Is this coincidence or some minority force of nature telling me something? Who knows? Let's see.

svn: E200033: database is locked, executing statement 'RELEASE s0'

noreply@blogger.com (Unknown) — Wed, 28 Aug 2013 01:38:00 +0000

Ok, so you're stuck when suddenly a commit transaction to svn repo crashes. SVN says you need to run "svn cleanup". That doesn't work either because of the error above. This means that your wc.db (working copy db) hasn't released its lock.

So how do you fix it? Replace your db with something new.

# cd /path/to/working/copy/.svn
# mv wc.db wc.db.old
# sqlite3 wc.db.old
sqlite> .backup main wc.db
sqlite> .exit

Got this amazing info here.

Yum Install Subversion 1.7x

noreply@blogger.com (Unknown) — Mon, 19 Aug 2013 12:02:00 +0000

If you're looking to upgrade your subversion client to 1.7 on CentOS 6 which most likely have a client version of 1.6x, then the easiest way to go is using Yum RPM manager.

First, you would need the rpmforge repo.

vi /etc/yum.repos.d/rpmforge.repo

### Name: RPMforge RPM Repository for RHEL 6 - dag
### URL: http://rpmforge.net/
[rpmforge]
name = RHEL $releasever - RPMforge.net - dag
baseurl = http://apt.sw.be/redhat/el6/en/$basearch/rpmforge
mirrorlist = http://apt.sw.be/redhat/el6/en/mirrors-rpmforge
#mirrorlist = file:///etc/yum.repos.d/mirrors-rpmforge
enabled = 1
protect = 0
gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-rpmforge-dag
gpgcheck = 0

[rpmforge-extras]
name = RHEL $releasever - RPMforge.net - extras
baseurl = http://apt.sw.be/redhat/el6/en/$basearch/extras
mirrorlist = http://apt.sw.be/redhat/el6/en/mirrors-rpmforge-extras
#mirrorlist = file:///etc/yum.repos.d/mirrors-rpmforge-extras
enabled = 1
protect = 0
gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-rpmforge-dag
gpgcheck = 0

[rpmforge-testing]
name = RHEL $releasever - RPMforge.net - testing
baseurl = http://apt.sw.be/redhat/el6/en/$basearch/testing
mirrorlist = http://apt.sw.be/redhat/el6/en/mirrors-rpmforge-testing
#mirrorlist = file:///etc/yum.repos.d/mirrors-rpmforge-testing
enabled = 0
protect = 0
gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-rpmforge-dag
gpgcheck = 0

Then,

yum remove subversion
yum install subversion.x86_64 subversion-devel.x86_64

Test Harness for REST Services

noreply@blogger.com (Unknown) — Mon, 12 Aug 2013 01:33:00 +0000

You don't have to write one to have a GUI client to test your REST API/services layer. You can use Chrome plug-in Advance REST Client here :

https://chrome.google.com/webstore/detail/advanced-rest-client/hgmloofddffdnphfgcellkdfbfbjeloo

If you're having trouble with JSON posts, maybe this can help.

http://stackoverflow.com/questions/11688608/how-to-test-express-node-rest-api-backend-with-advanced-rest-client-or-postman

Yum Install XCache Admin

noreply@blogger.com (Unknown) — Sun, 04 Aug 2013 20:50:00 +0000

# yum install xcache-admin

Yum Install XCache - A Superb Production Alternative for PHP Opcode Caching

noreply@blogger.com (Unknown) — Sun, 04 Aug 2013 17:02:00 +0000

Wanna gain as much as 5X your current PHP applications performance? Install XCache now to your server. It is tested to run in production and very stable. With XCache, no crazy error messages that has nothing to do with your code - how can a native function be mssing (APC is making a mess, remove it immediately)!?????

PHP Fatal error:  Call to undefined function in_array()

Here's how to install it in RHEL/CentOS.

First, you need the Remi repo information added to Yum registry. Copy and paste the following to your server repo registry.

# vim /etc/yum.repos.d/remi.repo
Then paste the following,

[remi]
name=Les RPM de remi pour Enterprise Linux 6 - $basearch
#baseurl=http://rpms.famillecollet.com/enterprise/6/remi/$basearch/
mirrorlist=http://rpms.famillecollet.com/enterprise/6/remi/mirror
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-remi

[remi-test]
name=Les RPM de remi en test pour Enterprise Linux 6 - $basearch
#baseurl=http://rpms.famillecollet.com/enterprise/6/test/$basearch/
mirrorlist=http://rpms.famillecollet.com/enterprise/6/test/mirror
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-remi

[remi-debuginfo]
name=Les RPM de remi pour Enterprise Linux 6 - $basearch - debuginfo
baseurl=http://rpms.famillecollet.com/enterprise/6/debug-remi/$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-remi

[remi-test-debuginfo]
name=Les RPM de remi en test pour Enterprise Linux 6 - $basearch - debuginfo
baseurl=http://rpms.famillecollet.com/enterprise/6/debug-test/$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-remi

# yum install php-xcache

Then tweak the configuration to your desired setting in /etc/php.d/xcache.ini.
Finally, reload your webserver configuration for it to take effect.

For more info go to http://xcache.lighttpd.net/wiki/Introduction

I am currently using this technology for ExploreTalent.com and the speed gain (~300% faster) have been very satisfying. Not to mention the cache-hit ratio of ~97% which indicates that it is indeed wonderfully working as expected. No crashes and weird missing PHP functions that you can encounter using APC or the rest especially observable in a high-traffic environment and with many cached objects.