Recently I’ve been working a bit with Log Parser Lizard and it’s been very helpful.
You can take log files, import them, pick the expected format, and then query them in a SQL style manner.
So for example, I took a bunch of IIS log files and was able to easily run this query against it:
where sc-status = 404 and cs-uri-stem <> '/AzureFileHandler.ashx'
and cs-uri-stem <> '/js/jquery.1.11.1.min.js'