The first part is to identify the PPID. I used this command to get my PPID for the mysql user:
# ps -A -mPl | grep mysql
I then used this command to get the total count for all child processes for the given PPID for the mysql user:
# ps -elm|grep 902|grep -v grep |wc -l
If you want to get a count of ALL processes, use the following command:
# ps -elm|wc -l
Kevin is putting a script together that will collect these counts periodically. One of us will post it to the article when tested and complete.