Centos Install MemCached, Apcu and OpCache

This section provides instructions to install memcached on CentOS and Ubuntu. For additional information, consult the memcached

To install memcached on CentOS, perform the following tasks as a user with root privileges: 

Install memcached and its dependencies:

yum -y update
yum install -y libevent libevent-devel
yum install -y memcached
yum install -y php-pecl-memcache

Change the memcached configuration setting for CACHESIZE and OPTIONS:

Open /etc/sysconfig/memcached in a text editor.

Locate the value for CACHESIZE and change it to at least 1GB. 

For example

CACHESIZE="1GB"

Service memcached restart

Restart your web server.

systemctl restart nginx

Install Apcu

These section we will install APCu (Alternative PHP Cache) on CentOS 7. APCu provided both opcode caching (opcache) and object caching APCu is the replacement for the outdated APC extension. It's very easy to install. Just follow these steps:

1. Install APCu . Before installing APCu, if your server doesn't have Remi Repository, install that first using this command:

sudo yum install http://rpms.remirepo.net/enterprise/remi-release-7.rpm

Now run this command to install APCu:

sudo yum install php-pecl-apcu

2. Dependency Packages for APCu , By entering this command, you can install dependency packages for APCu:

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

3. Restart Web Server

sudo systemctl restart nginx php-fpm

Now check your phpinfo(); script to see APCu is installed or not:

4. APCu Admin Page

This is an optional step. I’m sharing a PHP file. You need to keep this file to your domain’s public html folder to see APCu admin page. Download this file from GitHub: Now open the file from browser (http://example.com/apcu.php):

The default username and password is: admin, admin. You can change this from the apcu.php file:

#0 or 1. 0 for disable user and pass 

defaults('USE_AUTHENTICATION',0); 

defaults('ADMIN_USERNAME','admin'); 

defaults('ADMIN_PASSWORD','admin');

5. Config APCu

We can easily configure APCu. Open /etc/php.ini file and add value like this:

#Enable/Disable 

apc.enabled=1 

# Memory Segments 

apc.shm_size=512M 

## PHP file cache 1 hour## 

apc.ttl=3600 

## User cache 2 hour ## 

apc.user_ttl=7200 

## Garbage collection 1 hour ##  

apc.gc_ttl=3600

6. Store and Fetch Data

Create a file named cache.php and paste this code:

Now visit the cache.php to see the output.

Install OpCache

sudo yum install php-opcache -y

Now we can set our own config like:

nano /etc/php.d/10-opcache.ini

opcache.enable_cli=1
opcache.memory_consumption=128
opcache.interned_strings_buffer=8
opcache.max_accelerated_files=4000
opcache.revalidate_freq=60
opcache.fast_shutdown=1