How to Use Vultr Managed Database for Valkey in PHP

Introduction

Vultr Managed Database for Valkey is a highly available in-memory data store with flexible data structures such as strings, hashes, lists, and sets. You can use the database with PHP to build highly available applications with fast response rates as compared to disk-based databases.

This guide explains how to use a Vultr Managed Database for Valkey with PHP to interact with different data types in your web application.

Prerequisites

Before you begin:

• Deploy a Vultr Managed Database for Valkey
• Deploy a Vultr Ubuntu server to use as a development machine
• Using SSH, access the server as a non-root sudo user
• Install the Apache web server and PHP on the server

Prepare the Development Server

PHP is a server-side object-oriented programming language. To run PHP files, prepare the development server with the necessary packages and configurations. To integrate with a Vultr Managed Database for Valkey, install the php-redis extension and set up the web server configurations to read PHP files on the server.

1. Verify the installed PHP version on your server

    $ php -v

   Your output should look like the one below:

    PHP 8.1.2-1ubuntu2.14 (cli) (built: Aug 18 2023 11:41:11) (NTS)
    Copyright (c) The PHP Group
    Zend Engine v4.1.2, Copyright (c) Zend Technologies
        with Zend OPcache v8.1.2-1ubuntu2.14, Copyright (c), by Zend Technologies
   

2. Install the php-redis extension on your server

    $ sudo apt install php-redis
   

3. Enable the Apache PHP module on your server depending on your PHP version

    $ sudo a2enmod php8.1
   

4. Restart the Apache web server to save changes

    $ sudo systemctl restart apache2
   

5. Navigate to the Apache virtual host files directory

    $ cd /etc/apache2/sites-enabled
   

6. View your virtual host configuration file. By default, 000-default.conf

    $ cat 000-default.conf
   

7. Keep note of the configured DocumentRoot value. Usually, /var/www/html

    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/html
   

8. Allow the HTTP port 80 through your server firewall to access your PHP files

    $ sudo ufw allow 80/tcp
   

9. Using a text editor such as Nano, create a new info.php file in your web root directory

    $ nano /var/www/html/info.php
   

10. Add the following contents to the file to test your PHP and Valkey module configuration

     <?php
    
     if (extension_loaded('redis')) {
         echo 'The PHP Redis extension is installed on your server';
     } 
     else 
     {
         echo 'The PHP Redis extension is not installed. Please Install it and Restart Apache';
     }
    
     ?>

    Save and close the file

11. Visit your server IP address and load the info.php file

     http://SERVER-IP/info.php

    Verify that a PHP Valkey installed prompt displays on the web page

You have prepared your development server to read and serve PHP scripts. Integrate your Vultr Managed Database for Valkey to enhance your PHP application functions and sync with the database.

Create a Redis® PHP Database Class

To organize your PHP code, create a Redis® PHP database class to declare your database information. Within your PHP applications, you can import the class to use your Valkey database connection. Create a new connection class as described in the steps below.

1. Navigate to your web root directory to store PHP files

    $ cd /var/www/html/
   

2. Create a new RedisGateway.php file

    $ sudo nano RedisGateway.php
   

3. Add the following contents to the file. Replace the example values with your actual Vultr Managed Database for Valkey details in the $host, $port, $user, and $pass variables.

    <?php
   
    ini_set('display_errors', 1);
    ini_set('display_startup_errors', 1);
    error_reporting(E_ALL);
   
     class RedisGateway {
   
         public $redis_client;
   
         public function __construct()
         {
   
            $host = 'vultr-prod-example.vultrdb.com';
            $port = 16752;
            $user = "default";
            $pass = "example-password";   
   
            $redis = new Redis();
            $redis->connect("tls://" . $host, $port);
            $redis->auth([$user, $pass]);
   
            $this->redis_client = $redis;
         }
     }

   Save and close the file.

   Below is what the above PHP application methods and functions do:

   • __construct(): Initializes a connection to the Valkey server when you create an instance of the RedisGateway class using the PHP new keyword
   • $redis = new Redis();: imports the Redis® PHP driver
   • $redis->connect("tls://" . $host, $port);: Connects to the Vultr Managed Database for Valkey
   • $redis->auth([$user, $pass]);: Defines the Valkey database connection details
   • $this->redis_client = $redis;: Populates the $redis_client public property with the Valkey database connection details

4. To import the above PHP class, use the following declarations in your application

    require_once('RedisGateway.php');
   
    $redis_gateway = new RedisGateway();
    $redis_client  = $redis_gateway->redis_client;

Use Valkey Strings in PHP

A string is a collection of bytes. You can use the Valkey string data type to store text, binary arrays, and serialized objects. When using Valkey as a cache, you can use the string data type to store values such as login tokens, user profile information, and frequently visited HTML pages. Implement Valkey Strings in your application as described below.

1. Create a new redis_strings.php file

    $ sudo nano redis_strings.php
   

2. Add the following contents to the file

    <?php
   
        require_once('RedisGateway.php');
   
        $redis_gateway = new RedisGateway();
        $redis_client  = $redis_gateway->redis_client;
   
        $redis_key =  "john_doe";
        $key_value = "example-password";
   
        $redis_client->set($redis_key, $key_value); 
   
        $redis_client->expire($redis_key, 3600); 
   
        $redis_value = $redis_client->get($redis_key); 
   
        echo $redis_value ;

   Save and close the file.

   Below is what the above PHP application functions do:

   • require_once('RedisGateway.php');: Imports the custom RedisGateway class to use the Valkey connection information
   • $redis_client->set($redis_key, $key_value);: Sets a new key in the Valkey database
   • $redis_key: Creates a new Valkey key with the value john_doe
   • $key_value: Sets the Valkey key value to example-password
   • $redis_client->expire($redis_key, 3600);: Sets the Valkey key expiration time in seconds. 3600 sets the expiration time to 1 hour
   • $redis_client->get($redis_key);: Retrieves the Valkey key value from the database
   • echo $redis_value: Prints the Valkey key value from the database

3. Using the curl utility, run the PHP application using your localhost IP Address

    $ curl http://127.0.0.1/redis_strings.php

   Output:

    example-password

   As displayed in the above output, the PHP application prints the Valkey key-value example-password from the database.

Implement Valkey Hashes

A hash is a collection of field-value pairs. Unlike strings, a Valkey hash allows you to store multiple field values under one key. For instance, you can use a hash to save user session data in a Valkey database in a single key. Implement Valkey hashes in your PHP application as described below

1. Create a new redis_hashes.php file

    $ sudo nano redis_hashes.php
   

2. Add the following contents to the file

    <?php
   
        require_once('RedisGateway.php');
   
        $redis_gateway = new RedisGateway();
        $redis_client  = $redis_gateway->redis_client; 
   
        $redis_hash_key =  "users";
   
        $username = "john_doe";
        $password = "example-strong-password";
   
        $redis_client->hset($redis_hash_key, $username, $password);
   
        echo $redis_client->hget($redis_hash_key, $username);

   Save and close the file.

   In the above application code:

   • $redis_hash_key: Defines the Valkey hash key
   • $username: Defines the key for each element in the Valkey hash
   • $password: Stores the value for each element in the key
   • $redis_client->hset($redis_hash_key, $username, $password);: Creates and populates the Valkey hash with data
   • echo $redis_client->hget($redis_hash_key, $username);: Retrieves the value of a given key from the hash

3. Run the redis_hashes.php application file

    $ curl http://127.0.0.1/redis_hashes.php

   Output:

     example-strong-password

Implement Valkey Sorted Sets

A sorted set is a collection of unique Valkey strings ordered by an associated score. For example, in a fitness PHP application, you can use the Valkey set data type to store and analyze walking distances for the application users. Implement Valkey sorted sets as described in the following PHP application.

1. Create a new redis_sorted_sets.php file

    $ sudo nano redis_sorted_sets.php
   

2. Add the following contents to the file

    <?php
   
        require_once('RedisGateway.php');
   
        $redis_gateway = new RedisGateway();
        $redis_client  = $redis_gateway->redis_client; 
   
        $redis_set_key = 'steps_per_day';
   
        $redis_client->zadd($redis_set_key, 1910, 'JOHN'); 
        $redis_client->zadd($redis_set_key, 2180, 'JAMES');  
        $redis_client->zadd($redis_set_key, 5780, 'PETER');   
   
        print_r($redis_client->zrange($redis_set_key, 0, 2, true));  

   Save and close the file.

   In the above application:

   • $redis_set_key: Defines the name of the sorted Valkey set
   • $redis_client->zadd(...);: Adds a string and the associated score to the Valkey database
   • $redis_client->zrange($redis_set_key, 0, 2, true): Retrieves the sorted sets values from the Valkey database

3. Run the redis_sorted_sets.php application file

    $ curl http://127.0.0.1/redis_sorted_sets.php

   Output:

    Array
    (
        [JOHN] => 1910
        [JAMES] => 2180
        [PETER] => 5780
    )

Implement Valkey Lists

In Valkey, a list is an ordered sequence of strings for implementing stacks and queue-based applications. Valkey allows you to add values to the left or right side of a list using the lpush and rpush directives. lPop and rPop retrieve and remove elements from a list respectively. Implement Valkey lists as described in the following example PHP application

1. Create a new redis_lists.php file

    $ sudo nano redis_lists.php
   

2. Add the following contents to the file

    <?php
   
        require_once('RedisGateway.php');
   
        $redis_gateway = new RedisGateway();
        $redis_client  = $redis_gateway->redis_client; 
   
        $list_key = "countries";         
   
        $redis_client->lpush($list_key, "India");
        $redis_client->lpush($list_key, "Brazil");
        $redis_client->rpush($list_key, "France");
   
        $keys = $redis_client->lrange($list_key, 0, 2);
   
        print_r($keys);
   
        $i = 0;
   
        while ($redis_client->llen($list_key) > 0) {    
   
            print_r($redis_client->lPop($list_key));
   
            $i++;
   
        }

   Save and close the file.

   In the above PHP application:

   • $list_key: Declares the Valkey key name
   • $redis_client->lrange($list_key, 0, 2);: Retrieves all the list values from the Valkey server
   • $redis_client->llen($list_key): Finds the length of a list or the total elements in the list
   • while ($redis_client->llen($list_key) > 0) {...}: loops through the Valkey list and runs the lPop('test_list') function to display and remove elements from the list

3. Run the redis_lists.php application file

    $ curl http://127.0.0.1/redis_lists.php

   Output:

    Array
    (
        [0] => India
        [1] => Brazil
        [2] => France
    )

Conclusion

In this article, you have integrated a Vultr Managed Database for Valkey with PHP and implemented several data types to work with the stored database values. By implementing Valkey in your PHP application, you can speed up your application processes as compared to relational databases.