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.

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: localhost
  Alternatively, you can use the IP address 127.0.0.1.
• Port: 6379

Diagnostics

To verify Redis is running, type the following command:

systemctl 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:

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

redis-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:

   cd ~
   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:
   

   php 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:
   

   redis-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:

ls -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:

touch ~/.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.

Code sample

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

<?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

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

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, please see this article.
• For information about how to configure Drupal to use Redis, please see this article.
• For information about how to configure Joomla to use Redis, please see this article.
• For information about how to configure PrestaShop to use Redis, please see this article.
• For information about how to configure Magento to use Redis, please see this article.

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.