In this chapter we have covered different IIS log sources for understanding performance, reliability, and security in IIS server. Besides understanding the IIS logging structure, the general request processing flows, and running the sample queries, the core values delivered here are to help you realize what data is available in different log files and inspire creative thinking to derive meaningful information from this data. Microsoft Log parser is a free-form tool; it is up to system administrators like you to create useful queries and discover its true value.