The plugin "access_logs" analyzes all existing HTTP access logs on a system for multiple HTTP server software (like Apache, Tomcat or nginx).
It reads the current access log file backwards an catches all requests within the last 5 minutes (can be configured). It counts the HTTP response status codes to generate an overview and checks the percentual failure rate.
tac
command available within PATH environment. (part of GNU coreutils) gzip
command available within PATH environment. Needed, in case your access logs get gzip'ed during log rotation