The problem with fuzzy matching is that you will not be able to assign meaning without considerable manual labor after the analysis phase, and the analysis will probably break lines into pieces a human would not consider reasonable.

Instead, protect your head and consider the perl package "logwatch", which summarizes log files via email. It comes with ~60 service-specific filters to parse many unix log files. Unrecognized lines are simply passed through un-summarized, and then you'll know what filters you need to write/update.

It will at least get you started and may help you choose a solution path.