Fix RAG Retrieval Errors with CRAG, LangGraph, and Milvus

What this post added

This post details the implementation of a Corrective Retrieval-Augmented Generation (CRAG) system, enhancing RAG pipelines by adding an evaluation and correction step between retrieval and generation. It highlights Milvus's suitability for CRAG in production due to its multi-tenant isolation (Partition Key), hybrid retrieval capabilities (dense vectors, sparse vectors, scalar metadata filtering with RRF), and flexible schema management (dynamic JSON fields). The post provides a practical example of building a CRAG system using LangGraph middleware and Milvus, addressing common RAG failures like retrieval mismatch, stale content, and memory contamination.