We have a web site which produce roughly 100GB of IIS Web log files every month. We would like to get statistics from these logs, for instance the most visited URL's, authenticated users with most requests etc etc. We would also like some basic drill-down functionality, for instance to see what URL's the most frequent user accesses.
We've tested a few different tools for this but not found one which does't run into performance issues. For example, we tried SmarterStats and gave it 500GB of logs but it ran with 100% CPU usage for days and a few days later the service crashed. I know about Microsoft Log Parser, but what I'm looking for is a tool to generate easy-to-understand graphs which allows me to drill down.
Is there any tool to accomplish this, which can handle terabytes of log files?