On the shell, xargs can be used to queue parallel command processing. For example, for having always 3 sleeps in parallel, sleeping for 1 second each, and executing 10 sleeps in total do
echo {1..10} | xargs -d ' ' -n1 -P3 sh -c 'sleep 1s' _
And it would sleep for 4 seconds in total. If you have a list of names, and want to pass the names to commands executed, again executing 3 commands in parallel, do
cat names | xargs -n1 -P3 process_name
Would execute the command process_name alice, process_name bob and so on.