Description:
If your website is not responding and you see an Error 503 it means your website is currently inaccessible due to it consuming all of its allocated resources (RAM, CPU, Processes). It is not a problem with your web hosting service.This can happen if your website suddenly encounters a lot of visitors or if you are using a faulty WordPress plugin. This error is 'by design' to ensure you stay inside your hosting plan resource allocation. If the issue persists you may be able to upgrade to a higher tier package with more resources.
To see resource using login to DirectAdmin then click 'Extra Faatures' followed by 'Resource Usage'.