Using Managed Service for Redis clusters as PHP session storage

You can use Managed Service for Redis clusters for storing PHP session data.

To configure a Managed Service for Redis cluster as PHP session storage:

1. Configure PHP to use the Managed Service for Redis cluster as storage for sessions.
2. Check whether PHP session data is saved to the Managed Service for Redis cluster.

If you no longer need the resources you created, delete them.

Getting startedGetting started

Prepare the infrastructurePrepare the infrastructure

Configure additional settingsConfigure additional settings

1. Connect to the VM with the web server via SSH and configure it:

   • Install certificates:

     sudo mkdir --parents /usr/local/share/ca-certificates/Yandex/ && \
     sudo wget "https://storage.yandexcloud.net/cloud-certs/CA.pem" \
         --output-document /usr/local/share/ca-certificates/Yandex/YandexInternalRootCA.crt
     

   • Prepare the environment and install the phpredis library using pecl:

     sudo apt update && \
     sudo apt install php-dev pkg-php-tools redis-tools --yes && \
     sudo pecl channel-update pecl.php.net && \
     sudo pecl install redis
     

   • Become the owner of the /var/www/html/ directory and delete all its contents:

     sudo chown <username> /var/www/html/ --recursive && \
     rm /var/www/html/*
     

Configure PHP to use the Managed Service for Redis cluster as storage for sessionsConfigure PHP to use the Managed Service for Redis cluster as storage for sessions

1. Make changes to the php.ini configuration file for your web server.

   The php.ini file is usually located in the following directory:

   • /etc/php/7.2/apache2/ for Apache.
   • /etc/php/7.2/fpm/ for NGINX.

   To find out the location of php.ini, run the command sudo find /etc/ -name php.ini.

   Note

   There is no need to make any changes to php.ini for the PHP CLI.

   Non-sharded cluster

   Sharded cluster

   [PHP]
   ...
   extension = redis
   ...
   [Session]
   session.save_handler = redis
   session.save_path = "tcp://<FQDN_of_Redis_master_host>:6379?auth=<password>"
   

   [PHP]
   ...
   extension = redis
   ...
   [Session]
   session.save_handler = rediscluster
   session.save_path = "seed[]=<FQDN1>:6379&seed[]=<FQDN2>:6379&seed[]=<FQDN3>:6379&auth=<password>"
   

   Where <FQDN1>, <FQDN2>, and <FQDN3> are fully qualified domain names of cluster master hosts. For example, for a cluster with three shards and the password password, the session.save_path parameter value will look like this:

   session.save_path = "seed[]=rc1a-t9h8gxqo********.mdb.yandexcloud.net:6379&seed[]=rc1b-7qxk0h3b********.mdb.yandexcloud.net:6379&seed[]=rc1c-spy1c1i4********.mdb.yandexcloud.net:6379&auth=password"
   

   For more information about how to connect to clusters, see Setting up a connection.

2. Restart the web server:

   • sudo systemctl restart apache2 for Apache.
   • sudo systemctl restart php7.2-fpm for NGINX.

Check whether PHP session data is saved to the Managed Service for Redis clusterCheck whether PHP session data is saved to the Managed Service for Redis cluster

1. In the /var/www/html/ directory, create a file index.php that will output powers of 2:

   <?php
   session_start();
   
   $count = isset($_SESSION['count']) ? $_SESSION['count'] : 1;
   
   echo $count;
   
   $_SESSION['count'] = $count * 2;
   

   Each time the page is refreshed, the output value will increase. The $count variable value will be saved in the session data. A unique key will be created for each session in Redis.

2. Connect to the Redis cluster from the VM via redis-cli:

   redis-cli -c -h <FQDN_of_master_host> -a <password>
   

   Enter the following command to see what keys are stored in Redis:

   KEYS *
   

   (empty list or set)
   

   The returned result shows that no data is currently stored in Redis.

3. Check whether user sessions are saved when connecting to the web server:

   1. Enter the public IP of the VM hosting the web server in the browser address bar. The first time you open the page, 1 is output.
   2. Refresh the page several times: the output value will increase.
   3. Open the page from a different browser: the count will start with 1.
   4. Refresh the page several times: the output value will increase, too.

   The fact that the value of the $count variable is saved between browser page updates shows that the configured PHP session storage mechanism in the Managed Service for Redis cluster works properly.

4. Repeat the query to view the keys stored in Redis:

   KEYS *
   

   1) "PHPREDIS_SESSION:keb02haicgi0ijeju3********"
   2) "PHPREDIS_SESSION:c5r0mbe1v84pn2b5kj********"
   

   The returned result shows that, for each session in Redis, its own key is created.

Delete the resources you createdDelete the resources you created

Delete the resources you no longer need to avoid paying for them: