vibed services stop response after several days of work

[Suliman via Digitalmars-d-learn]

I got same problem on Windows Server 2016 and on Linux Debian 8.5.
I have few very simple backend based on vibed 0.8.1, compiler dmd 
2.075.1.

nginx servise is do port forwarding. Nothing more is used.

After several days of working I am begining to get "502 Bad 
Gateway" error. The service is not down, it's continue to 
working, but on Windows task manager I seen very low memory usage 
(0.4MB) and on Linux I see next: https://snag.gy/ban3jX.jpg (i am 
not familiar with Linux and do not sure if process is alive or 
not because htop do not show it)

The code is *very* simple https://github.com/bubnenkoff/dlang.ru

Is there any ideas how to diagnostic the problem?