How I Built Sherlog: an AI Log Analyzer with RAG, Spring AI, Groq & pgvector

Every developer knows the feeling: production throws an error, and you're staring at a wall of stack-trace text trying to find the one line that matters. So I built Sherlog — an AI "log detective" that reads an application log, figures out the root cause, and hands you a step-by-step fix as clean JSON. The twist: it doesn't just ask an LLM blindly. It uses RAG (Retrieval-Augmented Generation) to ground every answer in a knowledge base of past incidents. In this post I'll walk through how it wor