Can't see any changes in nohup.out

Question

I have a python script that I run on a server with this command:

sudo nohup python fetch_script.py &

It creates a nohup.out file on the same directory.

After a few days I came back and tried to check it, I did:

tail -f nohup.out

It gave me a result:

root@xx-xxx-xxx-xx:/home/ubuntu# tail -f nohup.out 
8809896
8809897
8809898
8809899
8809900
8809901
8809902
8809903
8809904
8809905

I waited a little bit but nothing happend. The script supposed to send messages to the RabbitMQ and update count and print it. The script was running the whole time, I know for sure, because I could see new messages where coming constantly. But nohup.out stuck. I also checked it with ls -l command to see if the size changed, but still no luck. Do you know what could be the reason for that? I assume that it will be eventually updated but don't know how long it would take. So are there any ways to constantly update this file? Will nice -20 help in this case?

UPDATE

Just rotate the Log, with /usr/sbin/logrotate waited a bit and saw changes in fresh nohup.out

Answer 1

The nohup.out file is written directly by the program that is being run under nohup, just like with normal shell redirection. If it's not being updated the problem is with the Python program, not with nohup itself.