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Load Balancing - Config Setup

Load balance multiple instances of the same model

The proxy will handle routing requests (using LiteLLM's Router). Set rpm in the config if you want maximize throughput

info

For more details on routing strategies / params, see Routing

Quick Start - Load Balancing​

Step 1 - Set deployments on config​

Example config below. Here requests with model=gpt-3.5-turbo will be routed across multiple instances of azure/gpt-3.5-turbo

model_list:
  - model_name: gpt-3.5-turbo
    litellm_params:
      model: azure/<your-deployment-name>
      api_base: <your-azure-endpoint>
      api_key: <your-azure-api-key>
      rpm: 6      # Rate limit for this deployment: in requests per minute (rpm)
  - model_name: gpt-3.5-turbo
    litellm_params:
      model: azure/gpt-turbo-small-ca
      api_base: https://my-endpoint-canada-berri992.openai.azure.com/
      api_key: <your-azure-api-key>
      rpm: 6
  - model_name: gpt-3.5-turbo
    litellm_params:
      model: azure/gpt-turbo-large
      api_base: https://openai-france-1234.openai.azure.com/
      api_key: <your-azure-api-key>
      rpm: 1440

Step 2: Start Proxy with config​

$ litellm --config /path/to/config.yaml

Step 3: Use proxy - Call a model group [Load Balancing]​

Curl Command

curl --location 'http://0.0.0.0:4000/chat/completions' \
--header 'Content-Type: application/json' \
--data ' {
      "model": "gpt-3.5-turbo",
      "messages": [
        {
          "role": "user",
          "content": "what llm are you"
        }
      ],
    }
'

Usage - Call a specific model deployment​

If you want to call a specific model defined in the config.yaml, you can call the litellm_params: model

In this example it will call azure/gpt-turbo-small-ca. Defined in the config on Step 1

curl --location 'http://0.0.0.0:4000/chat/completions' \
--header 'Content-Type: application/json' \
--data ' {
      "model": "azure/gpt-turbo-small-ca",
      "messages": [
        {
          "role": "user",
          "content": "what llm are you"
        }
      ],
    }
'

Load Balancing using multiple litellm instances (Kubernetes, Auto Scaling)​

LiteLLM Proxy supports sharing rpm/tpm shared across multiple litellm instances, pass redis_host, redis_password and redis_port to enable this. (LiteLLM will use Redis to track rpm/tpm usage )

Example config

model_list:
  - model_name: gpt-3.5-turbo
    litellm_params:
      model: azure/<your-deployment-name>
      api_base: <your-azure-endpoint>
      api_key: <your-azure-api-key>
      rpm: 6      # Rate limit for this deployment: in requests per minute (rpm)
  - model_name: gpt-3.5-turbo
    litellm_params:
      model: azure/gpt-turbo-small-ca
      api_base: https://my-endpoint-canada-berri992.openai.azure.com/
      api_key: <your-azure-api-key>
      rpm: 6
router_settings:
  redis_host: <your redis host>
  redis_password: <your redis password>
  redis_port: 1992

Router settings on config - routing_strategy, model_group_alias​

litellm.Router() settings can be set under router_settings. You can set model_group_alias, routing_strategy, num_retries,timeout . See all Router supported params here

Example config with router_settings

model_list:
  - model_name: gpt-3.5-turbo
    litellm_params:
      model: azure/<your-deployment-name>
      api_base: <your-azure-endpoint>
      api_key: <your-azure-api-key>
      rpm: 6      # Rate limit for this deployment: in requests per minute (rpm)
  - model_name: gpt-3.5-turbo
    litellm_params:
      model: azure/gpt-turbo-small-ca
      api_base: https://my-endpoint-canada-berri992.openai.azure.com/
      api_key: <your-azure-api-key>
      rpm: 6
router_settings:
  model_group_alias: {"gpt-4": "gpt-3.5-turbo"} # all requests with `gpt-4` will be routed to models with `gpt-3.5-turbo`
  routing_strategy: least-busy                  # Literal["simple-shuffle", "least-busy", "usage-based-routing", "latency-based-routing"]
  num_retries: 2
  timeout: 30                                  # 30 seconds
  redis_host: <your redis host>
  redis_password: <your redis password>
  redis_port: 1992