A simple bash oneliner to parse the server's access.log file to split by http error codes and count them individually.

parse_access_log.sh

tail -n 5000 /var/log/access.log | awk '{print $9}' | sort | uniq -c | sort -nr | head -n15

# Example of output:
#   2625 499
#   1433 500
#    569 200
#    243 401
#    108 404
#     16 301
#      6 302