Why my shell scripts are dying?

Question

Observation1

logic.sh

#!/bin/bash
#get system metrics
#do stuff and echo it
echo "put metrics" | nc $ip $port
echo "Metrics $metrics"

run_logic.sh

#!/bin/bash
while true;do
  sh logic.sh >> test.log 2>&1 &
  sleep 60
done

start_logic.sh

#!/bin/bash
case $1 in
  start)
       #start the run_logic.sh
       ;;
   stop)
      #stop the run_logic.sh
      ;;
    *)
     echo "Invalid Option!"
     exit 1
esac
exit0

Observation2

logic.sh

#!bin/bash
while true;do
  #do stuff and echo it
  #get System Metrics and put it
  echo $stuff
  sleep 60
done

start_logic.sh

#!/bin/bash
case $1 in
  start)
       #do some stuff, check already started or not
       sh logic.sh >> test.log 2>&1 &
       ;;
   stop)
      #do some stuff
      #Kill the process
      ;;
    *)
     echo "Invalid Option!"
     exit 1
esac
exit0

Now!, In observation1, the scripts are dying in middle of execution. I checked the logs, but I didn't see any error messages. In observation2, the scripts works fine(99% fine!). So, what is difference observation1 and observation2, why scripts are dying in the first case?

Answer 1

In observation 1, you start a shell, executing logic.sh every 60 seconds in the background (&). The used command netcat is supposed to send data to an ip/port, but if there is no-one listening on the remote end (tcp as default), it will exit with error.