How to configure Redis on managed servers

This article describes how to use Redis on the following hosting packages:

• Managed VPS
• Managed Dedicated server
• Turbo shared hosting accounts
• Turbo reseller accounts

Redis is an open-source memory object caching system that web sites can use to help accelerate page load times. Redis caches in RAM frequently accessed data, such as the results of API calls, database calls, and more.

Redis can significantly help improve site performance.

If you have a Turbo shared hosting account, you should use the Hostvento Hosting Optimized plugin to configure and manage Redis for many popular web applications (such as WordPress, Drupal, Joomla, and several others). The following information only applies if you want to use Redis in an application you have developed yourself, or if you are using an application that the Hostvento Optimized plugin does not support.Table of Contents

• Managed VPS and Dedicated servers
• Connection parameters
• Diagnostics
• Code sample
• Turbo shared hosting accounts
• Code sample
• Using Redis with web applications
• More Information

Managed VPS and Dedicated servers

Redis is installed and ready to use on managed VPS and managed Dedicated servers.

Connection parameters

You can connect to Redis using the following parameters:

• Hostname: localhostAlternatively, you can use the IP address 127.0.0.1.
• Port: 6379

Diagnostics

To verify Redis is running, type the following command:

Copysystemctl status redis

You can also use the redis-cli program to connect to Redis directly.

For example, the following commands demonstrate how to use redis-cli to dump all of the cached key-value pairs, and then display rolling statistics for Redis:

Copyredis-cli KEYS '*'
redis-cli --stat

To clear the entire Redis cache at once, type the following command:

Copyredis-cli FLUSHALL

Code sample

There are numerous PHP libraries available for integration with Redis. The following procedure demonstrates how to use the Predis library to connect to Redis and store a key/value pair:

1. Log in to your server using SSH.
2. At the command prompt, type the following commands:Copycd ~ composer require predis/predis
3. Using your preferred text editor, create a file named redis-test.php. Copy and then paste the following code into the redis-test.php file:
   <?php require ‘./vendor/predis/predis/autoload.php’; Predis\Autoloader::register(); $client = new Predis\Client(); $client->set(‘test’, ‘hello’); $value = $client->get(‘test’); print “test = ” . $value . “\n”; ?>
4. Save your changes to the redis-test.php file.
5. Type the following command to run the script:
   Copyphp redis-test.php
6. You should receive the following output:
   test = hello To confirm the key/value pair is stored in the Redis cache, type the following command:
   Copyredis-cli GET test

For more information about how to use PHP with Redis, please visit https://docs.redis.com/latest/rs/references/client_references/client_php.

Turbo shared hosting accounts

To connect to Redis on a Turbo shared hosting account, use the following Unix socket path. Replace username with your own account username:

/home/username/.redis/redis.sock

To verify that the Redis socket is active for your account, type the following command. Replace username with your own account username:

Copyls -l /home/username/.redis/redis.sock

If you receive a No such file or directory error message, then the socket has not been activated for your account yet. To do this, type the following command:

Copytouch ~/.redis.on

The server checks for this file every five minutes, and starts the Redis process for the account if it does not already exist. After five minutes, run the ls command above again, and you should see the redis.sock file in the directory listing.

Before you try to use Redis with PHP on your account, make sure the correct PHP extension is enabled. To do this, follow these steps:

1. Log in to cPanel.
2. In the SOFTWARE section of the cPanel home screen, click Select PHP Version.
3. In the list of PHP extensions, confirm that the Redis check box is selected. (If you do not see a list of PHP extensions, click the Extensions tab.)

Code sample

The following PHP code demonstrates how to connect to Redis and store a key-value pair in the cache.

If you run this code, remember to replace username with your own account username.

<?php

$redis = new Redis();
$redis->connect('/home/username/.redis/redis.sock');

$redis->set('test', 'hello');
$value = $redis->get('test');

print "test = " . $value . "\n";

?>

When you run this script, you should receive the following output:

test = hello

To confirm the key/value pair is stored in the Redis cache, type the following command:

Copyredis-cli -s ~/.redis/redis.sock GET test

Note that you must explicitly provide the socket path to redis-cli, or the command will fail.

Using Redis with web applications

A frequent use for Redis is to help improve performance in a CMS (content management system) like WordPress or Drupal. Redis can also help accelerate performance in e-commerce applications like PrestaShop or Magento:

• For information about how to configure WordPress to use Redis.
• For information about how to configure Drupal to use Redis.
• For information about how to configure Joomla to use Redis.
• For information about how to configure PrestaShop to use Redis.
• For information about how to configure Magento to use Redis.

More Information

• For more information about Redis, please visit https://redis.io.
• For more information about how to use PHP with Redis, please visit https://redis.io/docs/clients/#php.
• For more information about the Predis PHP library for Redis, please visit https://github.com/predis/predis.