Corpus 在 8GB RAM 下構建多租戶 RAG：為何不採用 Qdrant 和 Kafka（Phase 0）
Building a Multi-Tenant RAG in 8GB RAM: Why I Ditched Qdrant and Kafka (Phase 0)
Corpus 正以 8 GB RAM 和 6 vCPUs 構建多租戶 RAG 文件聊天平台，因硬件限制選用 PostgreSQL（pgvector）和 Redis，不自架 LLM，也不使用 Qdrant 或 Kafka。
I have 8 GB of RAM and 6 vCPUs. With those specs, I'm building and running a full production-ready RAG system.
I’m not self-hosting the LLM. I’m not spinning up Qdrant. I’m not adding Kafka.
Those aren't my personal preferences—they are constraints strictly dictated by the hardware. When you run a JVM alongside a Python AI worker on an 8 GB machine, every megabyte counts.
Today, I’m starting to build Corpus in public: a document chat platform where every answer strictly cites its sources, and each organization's data remains completely isolated from the rest (strict multi-tenancy).
The Stack (100% Dockerized)
- Backend API: Java 21 + Spring Boot 4
- AI & Embeddings Service: Python + FastAPI
-
Storage & Vector DB: PostgreSQL (
pgvector) + Redis - Frontend: React
Why this architecture?
-
PostgreSQL +
pgvectorover Qdrant/Milvus: Maintaining a dedicated vector database alongside a relational DB in 8 GB of RAM is overkill. Keeping relational metadata and vector embeddings in the same engine simplifies transactions and saves precious memory. - Redis over Kafka: I need asynchronous processing for document ingestion, not a massive distributed event-streaming cluster eating up heap memory.
Current Status: Phase 0
All 5 services spin up cleanly with a single docker compose up, and the core system design is locked in the repository. There is no live demo yet.
Next step: The ingestion pipeline—turning raw PDFs into queryable vector chunks without triggering the Linux OOM killer.
I’ll be documenting every architectural trade-off and every failure along the way.
🔗 GitHub Repository: aletgdev/corpus-rag
Looking for advice from the community 👇
For those of you who have built something similar under tight resource constraints: How would you handle local embedding generation within an 8 GB RAM budget while guaranteeing strict multi-tenant isolation in pgvector? (e.g., Row-Level Security vs. schema-per-tenant vs. metadata filtering).
Any war stories or tips are more than welcome in the comments!
來源：DEV Community · dev.to