Apache multi log analyze

[Eduard Ballester <ballester@ipsistemas.com>]

Hi
I've a web server farm in load balance...

I would like analyze all logs that they are rotated daily and kept in 
backup system.

I could consolidate them into a single log file (sorted by time) and then 
analize it but this single file is very large and I cannot keep it in disk 
by many days. I'm looking for a tool that is able to keep historical from 
each log analyzed and shows the accumulated results (by day, by week, by 
month, by year,...) something like MRTG (perhaps this is not a good 
comparison). do you understand me?

Do you know any tool to do this?

Thanks