Tableau does not currently have a native connector to point directly to (and parse out) web server log files. However, it is entirely possible to get the data from a log file into Tableau. We just first need to parse the log and put it into a format or database that Tableau can connect natively to, like Splunk, SQL Server, or a CSV.
1. Use Microsoft Log Parser To output to a CSV. We can then plug Tableau on top of the CSV and start playing with the data easily.
• This blog has a pretty straightforward walkthrough on how to do this (I tested it and it worked for me no problem), with various queries to pull specific things from an iis log into a csv: https://blogs.msdn.microsoft.com/carlosag/2010/03/25/analyze-your-iis-log-files-favorite-log-parser-queries/
• This github page just shows the single line command needed to put everything from an IIS log into CSV (once you have installed Microsoft Log Parser): https://gist.github.com/GuyHarwood/5540179
Or, you could use Microsoft Log Parser to put the files into SQL Server (this requires a powershell script. I have not tested this, bear in mind): http://www.technologytoolbox.com/blog/jjameson/archive/2012/02/29/import-website-iis-logs-into-sql-server-using-log-parser.aspx
2. If you have a Splunk server, connect Splunk to the IIS logs (http://docs.splunk.com/Documentation/AddOns/released/MSIIS/Setupaddon), then connect Tableau to Splunk.