library/Rediska/Command/GetRandomKey.php
public function create()
    {
        $connections = $this->_rediska->getConnections();
        $index = rand(0, count($connections) - 1);
        $connection = $connections[$index];

        $command = array('RANDOMKEY');

        return new Rediska_Connection_Exec($connection, $command);
    }
public function create()
    {
        $connections = $this->_rediska->getConnections();
        $index = rand(0, count($connections) - 1);
        $connection = $connections[$index];

        $command = array('RANDOMKEY');

        return new Rediska_Connection_Exec($connection, $command);
    }
Create command

@return Rediska_Connection_Exec