title: How to fix "Predis \ Response \ ServerException ERR syntax error"?
body: <p>It seems that my redis server is not working,anybody how to fix this?
  Thank you in advance</p>
  
  <pre class="lang-php prettyprint-override"><code>public static function getActiveUser($len = 10)
      {
          $key = config('rket.active_key');
          $users = Redis::zrevrange($key, 0, $len, 'WITHSOCRES');
          if (empty($users)) {
              return false;
          }
  
          return $users;
      }
  </code></pre>
  
  <p>this is where the problem happened.</p>