Logchecker

Lightweight, simple log checking utility. Checks log files for "unusual" entries and reports them. "Unusual" is defined as anything that does not match what the config says is "benign", so it's fail-safe.

You can define what is benign in two ways. The easy way is to let the program do it by itself automagically. Under certain circumstances this will not work very well (e.g. if there is part of the log entry that is often different), and then you can additionally use regular expressions.

This was originally written a long time ago, so there are probably more powerful options available out there now... but I still use it.