This document discusses big data architectures using Splunk, Hadoop, and relational databases. It begins with an overview of Splunk's scalability and real-time analytics capabilities. It then discusses Hunk, an analytics platform for Hadoop that provides self-service analytics. The document also examines using structured data in Splunk and connecting to relational databases. A case study examines challenges with the open source Hadoop ecosystem. Finally, it outlines a real-world customer architecture that uses Splunk for machine data, Hadoop for storage, Hunk for analytics, and connects to relational databases.