Many struggle in their job with the decision of what events to log in battle against costly increases to their licensing of a commercial SIEM or other logging solution. Leveraging the open source solutions used for "big-data" that have been proven by many can help build a scalable, reliable, and hackable event logging and security intelligence system to address security and (cringe) compliance requirements. We’ll walk through the various components and simple steps to building your own logging environment that can extensively grow (or keep sized just right) with just additional hardware cost and show numerous examples you can implement as soon as you get back to work (or home).