A nagios plugin script in python that calls top. This command does offer the percentage of CPU during a given interval, not for the whole lifetime of the process, like ps does. Additionally, with this script, one is able to monitor all the processes with the same name and check which one has the highest percent of CPU. Finally, there is a limitation in the top command, that it only allows up to twenty processes to be monitored at once, given their PID. In order to get over this limitation, a pool of threads is used and launches parallel top forks with twenty PIDs each.