Update Ollama context length configuration

- Rename OLLAMA_NUM_CTX to OLLAMA_LLM_NUM_CTX
- Increase default context window size
- Add requirement for minimum context size
- Update documentation examples

env.example

@@ -118,8 +118,9 @@ LLM_MODEL=gpt-4o
 LLM_BINDING_HOST=https://api.openai.com/v1
 LLM_BINDING_API_KEY=your_api_key
 
-### Set as num_ctx option for Ollama LLM
-# OLLAMA_NUM_CTX=32768
+### Set as num_ctx option for Ollama LLM (Must be larger than MAX_TOTAL_TOKENS+2000)
+### see also env.ollama-binding-options.example for fine tuning ollama
+# OLLAMA_LLM_NUM_CTX=32768
 
 ### Optional for Azure
 # AZURE_OPENAI_API_VERSION=2024-08-01-preview

lightrag/api/README-zh.md

@@ -69,8 +69,8 @@ LLM_BINDING=ollama
 LLM_MODEL=mistral-nemo:latest
 LLM_BINDING_HOST=http://localhost:11434
 # LLM_BINDING_API_KEY=your_api_key
-###  Ollama 服务器上下文 token 数（基于您的 Ollama 服务器容量）
-OLLAMA_NUM_CTX=8192
+###  Ollama 服务器上下文 token 数（必须大于 MAX_TOTAL_TOKENS+2000）
+OLLAMA_LLM_NUM_CTX=8192
 
 EMBEDDING_BINDING=ollama
 EMBEDDING_BINDING_HOST=http://localhost:11434

lightrag/api/README.md

@@ -69,8 +69,8 @@ LLM_BINDING=ollama
 LLM_MODEL=mistral-nemo:latest
 LLM_BINDING_HOST=http://localhost:11434
 # LLM_BINDING_API_KEY=your_api_key
-###  Ollama Server context length
-OLLAMA_NUM_CTX=8192
+###  Ollama Server context length (Must be larger than MAX_TOTAL_TOKENS+2000)
+OLLAMA_LLM_NUM_CTX=16384
 
 EMBEDDING_BINDING=ollama
 EMBEDDING_BINDING_HOST=http://localhost:11434

lightrag/llm/binding_options.py

@@ -240,7 +240,7 @@ class _OllamaOptionsMixin:
     """Options for Ollama bindings."""
 
     # Core context and generation parameters
-    num_ctx: int = 4096  # Context window size (number of tokens)
+    num_ctx: int = 32768  # Context window size (number of tokens)
     num_predict: int = 128  # Maximum number of tokens to predict
     num_keep: int = 0  # Number of tokens to keep from the initial prompt
     seed: int = -1  # Random seed for generation (-1 for random)
@@ -438,7 +438,7 @@ if __name__ == "__main__":
         # test LLM options
         ollama_options = OllamaLLMOptions.options_dict(args)
         print(ollama_options)
-        print(OllamaLLMOptions(num_ctx=32768).asdict())
+        print(OllamaLLMOptions(num_ctx=30000).asdict())
 
         # test embedding options
         embedding_options = OllamaEmbeddingOptions.options_dict(args)