How To Enable PHP 5.5 Opcache

Install Requirements

yum install gcc httpd-devel php-pear pcre-devel

Install Zend Opcache

yum install php-pecl-zendopcache

This will install Zend Opcache.

Restart Server

You will need to restart your server after installation for this to take effect:

sudo service httpd restart
Stopping httpd:                                            [  OK  ]
Starting httpd:                                            [  OK  ]

Test Installation

[root@ip-172-31-29-134 ec2-user]# php -v
PHP 5.6.9 (cli) (built: May 28 2015 00:59:21)
Copyright (c) 1997-2015 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2015 Zend Technologies
    with Zend OPcache v7.0.4-dev, Copyright (c) 1999-2015, by Zend Technologies 

On nginx (php-fpm)

[root@ip-172-31-29-134 ec2-user]# php-fpm -v
PHP 5.6.9 (fpm-fcgi) (built: May 28 2015 01:00:40)
Copyright (c) 1997-2015 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2015 Zend Technologies
    with Zend OPcache v7.0.4-dev, Copyright (c) 1999-2015, by Zend Technologies

Modify the Amount of RAM the Opcache Will Use

With Opcache, there is a trade-off between speed and the amount of RAM used.  The more RAM you are willing to dedicate to storing opcode, the more opcode that can be stored.  There is a diminishing return at some point because some code will execute rarely, or your code base might not be that big.  It is worth playing with this setting to see where you get the best performance vs. RAM trade-off.  This setting is in megabytes.

;opcache.memory_consumption=64

to

opcache.memory_consumption=128

Boost the Number of Scripts that Can Be Cached

Opcache has a strange setting that requires you to not only adjust the amount of RAM, but also define the number of scripts that can be cached.  You have the option of tuning this parameter for your own application too, especially if you find that your hit rate is not close to 100%.

;opcache.max_accelerated_files=2000

to
    
opcache.max_accelerated_files=4000

Change the Revalidate Frequency

To make sure that the Opcache notices when you change your PHP code, you can set the revalidate frequency.  Basically, this will tell the cache how often to check the timestamp on the files.  This is measured in seconds.

;opcache_revalidate_freq = 2

to

opcache_revalidate_freq = 240

Web Viewer (monitor tool)

1) Opcache-Status by Rasmus Lerdorf

Install

wget https://raw.github.com/rlerdorf/opcache-status/master/opcache.php

2) opcache-gui by amnuts

Install

wget https://raw.github.com/amnuts/opcache-gui/master/index.php -O op.php