What's the limit of drupal? I want to know what's the limit of drupal?:  


Maximum number of nodes .
Maximum number of content type .
Maximum of files 's size .  


And That without interruption of service . 
I am using Apache + mysql +redhat  .
Thank you very much
That depends on a lot of factors: hardware, configuration of your LAMP stack, ... 

The only real way to test this is to benchmark it yourself, on your hardware, under your circumstances. 

There's no real answer to this question.