This repository contains a JVM agent that samples thread stack traces and sends profiling data to a Riemann server. The agent is implemented in Java (Agent.java) which boots a Clojure runtime to perform the actual profiling logic. The core functionality involves periodically sampling stack traces of all runnable threads (excluding the sampler thread itself), aggregating them into a radix tree to estimate time spent per function, and sending the top functions as events to Riemann via HTTP. The design is lightweight and configurable, intended for production use in distributed systems like Hadoop clusters to identify CPU hotspots across thousands of nodes. The agent requires no application code changes and works with any JVM language.