By reference from error level of PHP, defined the error level of a service system.
As internet service or any system need to online 7*24 and service down was intolerable. A monitor system was needed to inform the person in charge. But the level of emergence need to be writing in advance. Below it’s my defination and explain.
The service was interrupted or Users can’t access. Had to active emergency plan or writting apologize letter.
Something big was happened. But thanks god, the service still accessable. You still have time to fix it before the boss found it.
Something wrong, better take a look.
You got unnormal active messege, maybe somewhere can tune better.
Messeges describe things happens. In easy words, “all quiet on the west front".