grepodata-websocket

ReactPHP WebSocket server for grepodata.com.

We use a Redis PubSub architecture for communication between the REST backend and websocket server.

Building

• Run composer install to install the required packages
• Copy config.example.php to config.private.php and set the Redis connection details
• Run Software/Application/WebSocket/server.php to start the WebSocket server

Deploy with supervisor

Install LibEv

LibEv is needed to get around the default open file limit of 1024.

• sudo apt install php-dev (Needed to run PHPIZE in the next step)
• sudo pecl install ev
• echo 'extension=ev.so' > /etc/php/7.2/mods-available/ev.ini
• sudo phpenmod ev

If the install was successful, the event loop should now be of type React\EventLoop\ExtEvLoop

Setup Supervisor

• Install supervisor: sudo apt-get install supervisor
• Override main supervisor conf: sudo cp supervisor/supervisord.conf /etc/supervisor/supervisord.conf
• Register websocket server as supervisor program: sudo cp supervisor/ratchet.conf /etc/supervisor/conf.d/ratchet.conf
• Enable as systemd service: sudo systemctl enable supervisor
• Start service: sudo systemctl start supervisor

Operational commands

• Reread updated config files: sudo supervisorctl reread
• Apply updates to conf: sudo supervisorctl update
• Check program status: sudo supervisorctl status
• Restart the websocket server: sudo supervisorctl restart ratchet:Ratchet

Scheduled Restart

The ReactPHP server is a bit unstable. A small amount of connections is never properly closed, leading to an accumulation of ghost connections. For this reason, we restart the server every other night using the following crontab: 11 02 */2 * * /usr/bin/supervisorctl restart ratchet:Ratchet