Implementing Multi-Site and Multiple Instances in Vtiger CRM

Understanding Vtiger's Multi-Instance Architecture

Vtiger CRM, built on PHP and leveraging Apache or LiteSpeed web servers, supports multi-instance setups where each instance operates independently. This is particularly useful for organizations that need separate CRM environments for different departments or subsidiaries. Each instance requires its own PHP configuration, Apache virtual host, and database schema. The challenge lies in ensuring that these instances do not conflict with each other while sharing the same underlying server resources.

Configuring PHP for Multiple Instances

When setting up multiple Vtiger instances on a single server, PHP configuration becomes critical. Each instance should ideally use the same PHP version to avoid compatibility issues, but with distinct settings tailored to its specific needs. Modify the php.ini file for each instance to ensure optimal performance:

memory_limit = 512M
upload_max_filesize = 50M
post_max_size = 50M
max_execution_time = 300
error_reporting = E_WARNING & ~E_NOTICE & ~E_DEPRECATED & ~E_STRICT
display_errors = Off
log_errors = On
short_open_tag = Off

These settings ensure that each instance has sufficient resources and adheres to Vtiger's recommended PHP configuration. Additionally, use PHP-FPM pools to isolate resources and prevent one instance from affecting others.

Setting Up Apache Virtual Hosts

Apache virtual hosts allow you to host multiple Vtiger instances on the same server, each accessible via a unique domain or subdomain. Create a separate virtual host configuration for each instance:

<VirtualHost *:80>
   ServerName instance1.example.com
   DocumentRoot /var/www/vtiger_instance1

   <Directory /var/www/vtiger_instance1>
       Options -Indexes +FollowSymLinks
       AllowOverride All
       Require all granted
   </Directory>
</VirtualHost>

Repeat this process for each instance, modifying the ServerName and DocumentRoot accordingly. Enable the virtual hosts and restart Apache:

sudo a2ensite vtiger_instance1.conf
sudo systemctl restart apache2

Database Isolation and Optimization

Each Vtiger instance requires its own database to ensure data isolation and prevent conflicts. Create separate databases and users for each instance in MariaDB:

CREATE DATABASE vtiger_instance1;
CREATE USER 'vtiger_user1'@'localhost' IDENTIFIED BY 'secure_password';
GRANT ALL PRIVILEGES ON vtiger_instance1.* TO 'vtiger_user1'@'localhost';
FLUSH PRIVILEGES;

Optimize MariaDB for Vtiger's relational schema by adjusting the MySQL configuration file:

[mysqld]
sql_mode = ""
max_allowed_packet = 64M
innodb_file_per_table = 1

These settings ensure that each instance operates efficiently and avoids common database bottlenecks.

Automating Workflows and Security

To maintain operational integrity across multiple instances, automate workflows using Vtiger's internal cron script. Add the following to your system's crontab for each instance:

*/5 * * * * cd /var/www/vtiger_instance1 && /usr/bin/php -f cron.php > /dev/null 2>&1

Finally, secure each instance by deleting the installer directory and enforcing HTTPS with Let's Encrypt SSL certificates:

sudo rm -rf /var/www/vtiger_instance1/install/

By following these steps, you can successfully deploy and manage multiple Vtiger CRM instances on a single server, ensuring optimal performance and data isolation.