|
| 1 | +# About GraphRAG LLMs |
| 2 | + |
| 3 | +## Overview |
| 4 | + |
| 5 | +GraphRAG uses three distinct LLMs, each optimized for different tasks in the pipeline: |
| 6 | + |
| 7 | +1. Dataprep LLM |
| 8 | +2. Retriever LLM |
| 9 | +3. Final LLM |
| 10 | + |
| 11 | +## 1. Dataprep LLM |
| 12 | + |
| 13 | +Used during data ingestion phase to: |
| 14 | + |
| 15 | +- Process and understand document structure |
| 16 | +- Extract entities and relationships between entities |
| 17 | +- Generate and store community summaries in Neo4j: |
| 18 | + |
| 19 | +```python |
| 20 | +# neo4j_llamaindex.py |
| 21 | +async def generate_community_summary(self, text): |
| 22 | + """Generate summary for a given text using an LLM.""" |
| 23 | + messages = [ |
| 24 | + ChatMessage( |
| 25 | + role="system", |
| 26 | + content=( |
| 27 | + "You are provided with a set of relationships from a knowledge graph... " |
| 28 | + "Your task is to create a summary of these relationships..." |
| 29 | + ), |
| 30 | + ) |
| 31 | + ] |
| 32 | + response = await self.llm.achat(trimmed_messages) |
| 33 | +``` |
| 34 | + |
| 35 | +**Key Requirements:** |
| 36 | + |
| 37 | +- High-quality model for accurate relationship understanding |
| 38 | +- Larger context window for document processing |
| 39 | +- Can be slower since it's one-time processing |
| 40 | + |
| 41 | +## 2. Retriever LLM |
| 42 | + |
| 43 | +Used during query processing to: |
| 44 | + |
| 45 | +- Evaluate relevance of pre-computed community summaries |
| 46 | +- Generate specific answers from relevant communities |
| 47 | +- Process multiple communities in parallel |
| 48 | + |
| 49 | +```python |
| 50 | +def generate_answer_from_summary(self, community_summary, query): |
| 51 | + """Generate an answer from a community summary based on a given query using LLM.""" |
| 52 | + prompt = ( |
| 53 | + f"Given the community summary: {community_summary}, " |
| 54 | + f"how would you answer the following query? Query: {query}" |
| 55 | + ) |
| 56 | + response = self._llm.chat(messages) |
| 57 | +``` |
| 58 | + |
| 59 | +**Key Requirements:** |
| 60 | + |
| 61 | +- Fast inference for real-time processing |
| 62 | +- Efficient batch processing capabilities |
| 63 | +- Balance between quality and speed |
| 64 | + |
| 65 | +## 3. Final LLM |
| 66 | + |
| 67 | +Used as the last step to: |
| 68 | + |
| 69 | +- Process all retriever-generated answers |
| 70 | +- Synthesize information from multiple communities |
| 71 | +- Generate coherent final response |
| 72 | + |
| 73 | +```python |
| 74 | +# In graphrag.py |
| 75 | +llm = MicroService( |
| 76 | + name="llm", |
| 77 | + host=LLM_SERVER_HOST_IP, |
| 78 | + port=LLM_SERVER_PORT, |
| 79 | + endpoint="/v1/chat/completions", |
| 80 | + service_type=ServiceType.LLM, |
| 81 | +) |
| 82 | +``` |
| 83 | + |
| 84 | +**Key Requirements:** |
| 85 | + |
| 86 | +- Good at synthesizing multiple sources |
| 87 | +- Strong natural language generation |
| 88 | +- Maintains context across multiple inputs |
| 89 | + |
| 90 | +## Data Flow |
| 91 | + |
| 92 | +1. **Ingestion Phase** |
| 93 | + |
| 94 | + - Documents → Dataprep LLM → Community Summaries |
| 95 | + - Summaries stored in Neo4j |
| 96 | + |
| 97 | +2. **Query Phase** |
| 98 | + - Query → Retriever LLM → Individual Community Answers |
| 99 | + - Answers → Final LLM → Coherent Response |
| 100 | + |
| 101 | +## Configuration |
| 102 | + |
| 103 | +Each LLM can be configured independently through environment variables: |
| 104 | + |
| 105 | +- `DATAPREP_LLM_ENDPOINT` and `DATAPREP_LLM_MODEL_ID` |
| 106 | +- `RETRIEVER_LLM_ENDPOINT` and `RETRIEVER_LLM_MODEL_ID` |
| 107 | +- `FINAL_LLM_ENDPOINT` and `FINAL_LLM_MODEL_ID` |
| 108 | + |
| 109 | +This allows for optimization of each LLM for its specific task in the pipeline. |
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