Redis is an in-memory data structure project implementing a distributed, in-memory key–value database with optional durability. Redis supports different kinds of abstract data structures, such as strings, lists, maps, sets, sorted sets, HyperLogLogs, bitmaps, streams, and spatial indexes.

To use Redis client module on CentOS 7, you should run below commands:

sudo yum --enablerepo=epel -y install php-pecl-redis redis redis-server
sudo systemctl start redis
sudo systemctl enable redis


If everything is okay, you can simply test Redis like below in PHP:

<?php
$redis = new Redis();
$redis->connect("127.0.0.1",6379);
$redis->auth("password"); // if you assigned

// set and get Key
$redis->set('key01', 'value01');
print 'key01.value : ' . $redis->get('key01') . "\n";

// append and get Key
$redis->append('key01', ',value02');
print 'key01.value : ' . $redis->get('key01') . "\n";

$redis->set('key02', 1);
print 'key02.value : ' . $redis->get('key02') . "\n";

// increment
$redis->incr('key02', 100);
print 'key02.value : ' . $redis->get('key02') . "\n";

// decrement
$redis->decr('key02', 51);
print 'key02.value : ' . $redis->get('key02') . "\n";

// list
$redis->lPush('list01', 'value01');
$redis->rPush('list01', 'value02');
print 'list01.value : ';
print_r ($redis->lRange('list01', 0, -1));

// hash
$redis->hSet('hash01', 'key01', 'value01');
$redis->hSet('hash01', 'key02', 'value02');
print 'hash01.value : ';
print_r ($redis->hGetAll('hash01'));

// set
$redis->sAdd('set01', 'member01');
$redis->sAdd('set01', 'member02');
print 'set01.value : ';
print_r ($redis->sMembers('set01'));
?>

You will see the result like:

key01.value : value01
key01.value : value01,value02
key02.value : 1
key02.value : 101
key02.value : 50
list01.value : Array
(
    [0] => value01
    [1] => value02
)
hash01.value : Array
(
    [key01] => value01
    [key02] => value02
)
set01.value : Array
(
    [0] => member01
    [1] => member02
)

In case that you need to erase all the nodes in the database, you should run:

redis-cli FLUSHDB