CODEWITHSUNDEEP
pythonsshremote-server
diviquery
diviquery

Reputation: 759

Can't execute a remote Python script with sleep(.) from SSH

I am trying to execute a Python script on a remote server via SSH. The script is supposed to run a certain function every few seconds. A minimal working snippet is as follows:

# test.py (this is on the remote server in $HOME)
import sys
import time

def test(num_samples):
    # First start with a monitoring period of 50 seconds.
    monitoring_period = 5
    a = 0
    
    while a < num_samples:
        print(a, num_samples)
        time.sleep(monitoring_period)        
        a += 1000

if __name__ == "__main__":
    print("Start")
    test(int(sys.argv[1]))

When I run the above script directly on the remote server, it executes successfully:

node0:~$ python test.py 500
Start
0 500

However, when I try to run the same script via SSH - it just stalls (and note that even the first print statement "Start" is also not executed:

❯ ssh -o StrictHostKeyChecking=no <user>@<remote-server> "pushd \$HOME; python test.py 500"
~ ~
// It stalls here

More interestingly, if I remove the time.sleep(.) statement from the above script, it executes just fine:

❯ ssh -o StrictHostKeyChecking=no <user>@<remote-server> "pushd \$HOME; python test.py 500"
~ ~
Start
0 500
  1. What exactly is going on? Does the sleep(.) statement cause this issue?
  2. If so, is the Python interpreter somehow checking for it before even executing the first statement in the script (the print("Start") statement)?

Upvotes: 0

Views: 22

Answers (0)

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