sudo apt-get install php7.1 php7.1-imap php7.1-xml php7.1-dom php7.1-intl

sudo update-alternatives --set php /usr/bin/php7.1

php -f bin/magento cache:enable

php -f bin/magento cache:flush

sudo apt-get update
sudo apt-get install build-essential tcl8.5
sudo apt-get install make
wget http://download.redis.io/redis-stable.tar.gz
tar xvzf redis-stable.tar.gz
cd redis-stable
make
cd utils/
sudo ./install_server.sh

'cache' =>
  array (
    'frontend' =>
    array (
      'default' =>
      array (
        'backend' => 'Cm_Cache_Backend_Redis',
        'backend_options' =>
        array (
          'server' => '127.0.0.1',
          'database' => '0',
          'port' => '6379',
        ),
      ),
      'page_cache' =>
      array (
        'backend' => 'Cm_Cache_Backend_Redis',
        'backend_options' =>
        array (
          'server' => '127.0.0.1',
          'port' => '6379',
          'database' => '1',
          'compress_data' => '0',
        ),
      ),
    ),
  ),

apt-get install php7.1-fpm
a2enmod proxy_fcgi setenvif
a2enconf php7.1-fpm
sudo service php7.1-fpm restart
sudo service apache2 restart

opcache.enable=1