HTTP 503 – Service Unavailable – craft\web\ServiceUnavailableHttpException I have a problem with my page after upload on server. Currently a enabled devMode and while loading it shows 


  HTTP 503 – Service Unavailable – craft\web\ServiceUnavailableHttpException 
  
  whatmore:
  
  vendor/yiisoft/yii2/base/Application.php at line 386 – craft\web\Application::handleRequest(craft\web\Request)


web.log below:


  2018-07-19 07:11:06 [80.55.43.241][-][72baf4994c2e29ee1f32982349aec971][info][yii\db\Connection::open] Opening DB connection: mysql:host=localhost;dbname=my_database;port=3306;
  2018-07-19 07:11:06 [80.55.43.241][-][72baf4994c2e29ee1f32982349aec971][profile begin][yii\db\Connection::open] Opening DB connection: mysql:host=localhost;dbname=my_database;port=3306;
  2018-07-19 07:11:06 [80.55.43.241][-][72baf4994c2e29ee1f32982349aec971][profile end][yii\db\Connection::open] Opening DB connection: mysql:host=localhost;dbname=my_database;port=3306;
  2018-07-19 07:11:06 [80.55.43.241][-][72baf4994c2e29ee1f32982349aec971][error][craft\db\Connection::open] SQLSTATE[HY000] [2002] No such file or directory
  2018-07-19 07:11:06 [80.55.43.241][-][72baf4994c2e29ee1f32982349aec971][error][craft\db\Connection::open] SQLSTATE[HY000] [2002] No such file or directory
  2018-07-19 07:11:06 [80.55.43.241][-][72baf4994c2e29ee1f32982349aec971][info][yii\web\Session::open] Session started
  2018-07-19 07:11:06 [80.55.43.241][-][72baf4994c2e29ee1f32982349aec971][error][yii\web\HttpException:503] craft\web\ServiceUnavailableHttpException in /path/to/public_html/www/vendor/craftcms/cms/src/web/Application.php:507
  Stack trace:
  
  0 /home/cluster-sites/3/t/toolmach.co.uk/public_html/www/vendor/craftcms/cms/src/web/Application.php(184): craft\web\Application->_processInstallRequest(Object(craft\web\Request))
  
  1 /home/cluster-sites/3/t/toolmach.co.uk/public_html/www/vendor/yiisoft/yii2/base/Application.php(386): craft\web\Application->handleRequest(Object(craft\web\Request))
  
  2 /home/cluster-sites/3/t/toolmach.co.uk/public_html/www/web/index.php(21): yii\base\Application->run()
  
  3 {main}
  2018-07-19 07:11:07 [80.55.43.241][-][72baf4994c2e29ee1f32982349aec971][trace][yii\base\View::renderFile] Rendering view file: /path/to/public_html/www/vendor/yiisoft/yii2/views/errorHandler/exception.php
  2018-07-19 07:11:07 [80.55.43.241][-][72baf4994c2e29ee1f32982349aec971][trace][yii\base\View::renderFile] Rendering view file: /path/to/public_html/www/vendor/yiisoft/yii2/views/errorHandler/callStackItem.php
  2018-07-19 07:11:07 [80.55.43.241][-][72baf4994c2e29ee1f32982349aec971][trace][yii\base\View::renderFile] Rendering view file: /path/to/public_html/www/vendor/yiisoft/yii2/views/errorHandler/callStackItem.php
  2018-07-19 07:11:07 [80.55.43.241][-][72baf4994c2e29ee1f32982349aec971][trace][yii\base\View::renderFile] Rendering view file: /path/topublic_html/www/vendor/yiisoft/yii2/views/errorHandler/callStackItem.php
  2018-07-19 07:11:07 [80.55.43.241][-][72baf4994c2e29ee1f32982349aec971][trace][yii\base\View::renderFile] Rendering view file: /path/topublic_html/www/vendor/yiisoft/yii2/views/errorHandler/callStackItem.php
  2018-07-19 07:11:05 [80.55.43.241][-][72baf4994c2e29ee1f32982349aec971][info][application] $_GET = []
  
  $_POST = []
  
  $_FILES = []
This isn't a direct answer to your question, but the first place I'd look is your logs on your server. As an example, I'm running nginx on my server and the logs are located in /var/log/nginx/.