discodb looks great for analysing analytics data appending data to a file is a pretty cheap operation, just make sure you append properly and dont do something

discodb looks great for analysing analytics data appending data to a file is a pretty cheap operation, just make sure you append properly and dont do something like read the whole file, append the string, then write it all, a lightweight server like mochiweb will probably have you handling more traffic than you can handle for a while before having to do a proper logging queue.