One logfile for multiple sites

How should we approach breaking them up?

[stuartmcdonald]

A client has set up a series of sites (dozens) in a rather peculiar manner which results in all of the sites having their logfiles recorded into the one central logfile.

Now she wants to be able to offer separate stats to each site but most of the stats programs choke on this multiple site logfile.

Initially we thought about splitting the logs out on a nightly basis but we couldn't get that to work properly without server performance issues. Now we're considering "duplicating" the logfile for each site, by writing every request to a textfile for each site. The site is IIS/ASP -- if anyone has any warnings/suggestions about an approach like this, it would be much appreciated.

[cgrantski]

I have no warnings but we've accomplished the same goal without stress to the server by copying the log nightly to another machine where the more CPU-intensive splitting-out happens.

Or you could skip the splitting out if your software is able to produce separate reports from one log. That's a pretty common feature.