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Caching

note

For OpenAI/Anthropic Prompt Caching, go here

Cache LLM Responses. LiteLLM's caching system stores and reuses LLM responses to save costs and reduce latency. When you make the same request twice, the cached response is returned instead of calling the LLM API again.

Supported Caches​

  • In Memory Cache
  • Redis Cache
  • Qdrant Semantic Cache
  • Redis Semantic Cache
  • s3 Bucket Cache

Quick Start​

Caching can be enabled by adding the cache key in the config.yaml

Step 1: Add cache to the config.yaml​

model_list:
  - model_name: gpt-3.5-turbo
    litellm_params:
      model: gpt-3.5-turbo
  - model_name: text-embedding-ada-002
    litellm_params:
      model: text-embedding-ada-002

litellm_settings:
  set_verbose: True
  cache: True          # set cache responses to True, litellm defaults to using a redis cache

[OPTIONAL] Step 1.5: Add redis namespaces, default ttl​

Namespace​

If you want to create some folder for your keys, you can set a namespace, like this:

litellm_settings:
  cache: true 
  cache_params:        # set cache params for redis
    type: redis
    namespace: "litellm.caching.caching"

and keys will be stored like:

litellm.caching.caching:<hash>

Redis Cluster​

model_list:
  - model_name: "*"
    litellm_params:
      model: "*"


litellm_settings:
  cache: True
  cache_params:
    type: redis
    redis_startup_nodes: [{"host": "127.0.0.1", "port": "7001"}]

Redis Sentinel​

model_list:
  - model_name: "*"
    litellm_params:
      model: "*"


litellm_settings:
  cache: true
  cache_params:
    type: "redis"
    service_name: "mymaster"
    sentinel_nodes: [["localhost", 26379]]
    sentinel_password: "password" # [OPTIONAL]

TTL​

litellm_settings:
  cache: true 
  cache_params:        # set cache params for redis
    type: redis
    ttl: 600 # will be cached on redis for 600s
    # default_in_memory_ttl: Optional[float], default is None. time in seconds. 
    # default_in_redis_ttl: Optional[float], default is None. time in seconds.

SSL​

just set REDIS_SSL="True" in your .env, and LiteLLM will pick this up. 

REDIS_SSL="True"

For quick testing, you can also use REDIS_URL, eg.:

REDIS_URL="rediss://.."

but we don't recommend using REDIS_URL in prod. We've noticed a performance difference between using it vs. redis_host, port, etc.

Step 2: Add Redis Credentials to .env​

Set either REDIS_URL or the REDIS_HOST in your os environment, to enable caching.

REDIS_URL = ""        # REDIS_URL='redis://username:password@hostname:port/database'
## OR ## 
REDIS_HOST = ""       # REDIS_HOST='redis-18841.c274.us-east-1-3.ec2.cloud.redislabs.com'
REDIS_PORT = ""       # REDIS_PORT='18841'
REDIS_PASSWORD = ""   # REDIS_PASSWORD='liteLlmIsAmazing'

Additional kwargs
You can pass in any additional redis.Redis arg, by storing the variable + value in your os environment, like this: 

REDIS_<redis-kwarg-name> = ""

See how it's read from the environment

Step 3: Run proxy with config​

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

Usage​

Basic​

Send the same request twice:

curl http://0.0.0.0:4000/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
     "model": "gpt-3.5-turbo",
     "messages": [{"role": "user", "content": "write a poem about litellm!"}],
     "temperature": 0.7
   }'

curl http://0.0.0.0:4000/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
     "model": "gpt-3.5-turbo",
     "messages": [{"role": "user", "content": "write a poem about litellm!"}],
     "temperature": 0.7
   }'

Dynamic Cache Controls​

ParameterTypeDescription
ttlOptional(int)Will cache the response for the user-defined amount of time (in seconds)
s-maxageOptional(int)Will only accept cached responses that are within user-defined range (in seconds)
no-cacheOptional(bool)Will not store the response in cache.
no-storeOptional(bool)Will not cache the response
namespaceOptional(str)Will cache the response under a user-defined namespace

Each cache parameter can be controlled on a per-request basis. Here are examples for each parameter:

ttl​

Set how long (in seconds) to cache a response.

from openai import OpenAI

client = OpenAI(
    api_key="your-api-key",
    base_url="http://0.0.0.0:4000"
)

chat_completion = client.chat.completions.create(
    messages=[{"role": "user", "content": "Hello"}],
    model="gpt-3.5-turbo",
    extra_body={
        "cache": {
            "ttl": 300  # Cache response for 5 minutes
        }
    }
)

s-maxage​

Only accept cached responses that are within the specified age (in seconds).

from openai import OpenAI

client = OpenAI(
    api_key="your-api-key",
    base_url="http://0.0.0.0:4000"
)

chat_completion = client.chat.completions.create(
    messages=[{"role": "user", "content": "Hello"}],
    model="gpt-3.5-turbo",
    extra_body={
        "cache": {
            "s-maxage": 600  # Only use cache if less than 10 minutes old
        }
    }
)

no-cache​

Force a fresh response, bypassing the cache.

from openai import OpenAI

client = OpenAI(
    api_key="your-api-key",
    base_url="http://0.0.0.0:4000"
)

chat_completion = client.chat.completions.create(
    messages=[{"role": "user", "content": "Hello"}],
    model="gpt-3.5-turbo",
    extra_body={
        "cache": {
            "no-cache": True  # Skip cache check, get fresh response
        }
    }
)

no-store​

Will not store the response in cache.

from openai import OpenAI

client = OpenAI(
    api_key="your-api-key",
    base_url="http://0.0.0.0:4000"
)

chat_completion = client.chat.completions.create(
    messages=[{"role": "user", "content": "Hello"}],
    model="gpt-3.5-turbo",
    extra_body={
        "cache": {
            "no-store": True  # Don't cache this response
        }
    }
)

namespace​

Store the response under a specific cache namespace.

from openai import OpenAI

client = OpenAI(
    api_key="your-api-key",
    base_url="http://0.0.0.0:4000"
)

chat_completion = client.chat.completions.create(
    messages=[{"role": "user", "content": "Hello"}],
    model="gpt-3.5-turbo",
    extra_body={
        "cache": {
            "namespace": "my-custom-namespace"  # Store in custom namespace
        }
    }
)

Set cache for proxy, but not on the actual llm api call​

Use this if you just want to enable features like rate limiting, and loadbalancing across multiple instances.

Set supported_call_types: [] to disable caching on the actual api call. 

litellm_settings:
  cache: True
  cache_params:
    type: redis
    supported_call_types: []

Debugging Caching - /cache/ping​

LiteLLM Proxy exposes a /cache/ping endpoint to test if the cache is working as expected

Usage

curl --location 'http://0.0.0.0:4000/cache/ping'  -H "Authorization: Bearer sk-1234"

Expected Response - when cache healthy

{
    "status": "healthy",
    "cache_type": "redis",
    "ping_response": true,
    "set_cache_response": "success",
    "litellm_cache_params": {
        "supported_call_types": "['completion', 'acompletion', 'embedding', 'aembedding', 'atranscription', 'transcription']",
        "type": "redis",
        "namespace": "None"
    },
    "redis_cache_params": {
        "redis_client": "Redis<ConnectionPool<Connection<host=redis-16337.c322.us-east-1-2.ec2.cloud.redislabs.com,port=16337,db=0>>>",
        "redis_kwargs": "{'url': 'redis://:******@redis-16337.c322.us-east-1-2.ec2.cloud.redislabs.com:16337'}",
        "async_redis_conn_pool": "BlockingConnectionPool<Connection<host=redis-16337.c322.us-east-1-2.ec2.cloud.redislabs.com,port=16337,db=0>>",
        "redis_version": "7.2.0"
    }
}

Advanced​

Control Call Types Caching is on for - (/chat/completion, /embeddings, etc.)​

By default, caching is on for all call types. You can control which call types caching is on for by setting supported_call_types in cache_params

Cache will only be on for the call types specified in supported_call_types

litellm_settings:
  cache: True
  cache_params:
    type: redis
    supported_call_types: ["acompletion", "atext_completion", "aembedding", "atranscription"]
                          # /chat/completions, /completions, /embeddings, /audio/transcriptions

Set Cache Params on config.yaml​

model_list:
  - model_name: gpt-3.5-turbo
    litellm_params:
      model: gpt-3.5-turbo
  - model_name: text-embedding-ada-002
    litellm_params:
      model: text-embedding-ada-002

litellm_settings:
  set_verbose: True
  cache: True          # set cache responses to True, litellm defaults to using a redis cache
  cache_params:         # cache_params are optional
    type: "redis"  # The type of cache to initialize. Can be "local" or "redis". Defaults to "local".
    host: "localhost"  # The host address for the Redis cache. Required if type is "redis".
    port: 6379  # The port number for the Redis cache. Required if type is "redis".
    password: "your_password"  # The password for the Redis cache. Required if type is "redis".
    
    # Optional configurations
    supported_call_types: ["acompletion", "atext_completion", "aembedding", "atranscription"]
                      # /chat/completions, /completions, /embeddings, /audio/transcriptions

Deleting Cache Keys - /cache/delete​

In order to delete a cache key, send a request to /cache/delete with the keys you want to delete

Example 

curl -X POST "http://0.0.0.0:4000/cache/delete" \
  -H "Authorization: Bearer sk-1234" \
  -d '{"keys": ["586bf3f3c1bf5aecb55bd9996494d3bbc69eb58397163add6d49537762a7548d", "key2"]}'
# {"status":"success"}

Viewing Cache Keys from responses​

You can view the cache_key in the response headers, on cache hits the cache key is sent as the x-litellm-cache-key response headers

curl -i --location 'http://0.0.0.0:4000/chat/completions' \
    --header 'Authorization: Bearer sk-1234' \
    --header 'Content-Type: application/json' \
    --data '{
    "model": "gpt-3.5-turbo",
    "user": "ishan",
    "messages": [
        {
        "role": "user",
        "content": "what is litellm"
        }
    ],
}'

Response from litellm proxy 

date: Thu, 04 Apr 2024 17:37:21 GMT
content-type: application/json
x-litellm-cache-key: 586bf3f3c1bf5aecb55bd9996494d3bbc69eb58397163add6d49537762a7548d

{
    "id": "chatcmpl-9ALJTzsBlXR9zTxPvzfFFtFbFtG6T",
    "choices": [
        {
            "finish_reason": "stop",
            "index": 0,
            "message": {
                "content": "I'm sorr.."
                "role": "assistant"
            }
        }
    ],
    "created": 1712252235,
}

Set Caching Default Off - Opt in only ​

  1. Set mode: default_off for caching
model_list:
  - model_name: fake-openai-endpoint
    litellm_params:
      model: openai/fake
      api_key: fake-key
      api_base: https://exampleopenaiendpoint-production.up.railway.app/

# default off mode
litellm_settings:
  set_verbose: True
  cache: True
  cache_params:
    mode: default_off # 👈 Key change cache is default_off
  1. Opting in to cache when cache is default off
import os
from openai import OpenAI

client = OpenAI(api_key=<litellm-api-key>, base_url="http://0.0.0.0:4000")

chat_completion = client.chat.completions.create(
    messages=[
        {
            "role": "user",
            "content": "Say this is a test",
        }
    ],
    model="gpt-3.5-turbo",
    extra_body = {        # OpenAI python accepts extra args in extra_body
        "cache": {"use-cache": True}
    }
)

Turn on batch_redis_requests​

What it does? When a request is made:

  • Check if a key starting with litellm:<hashed_api_key>:<call_type>: exists in-memory, if no - get the last 100 cached requests for this key and store it

  • New requests are stored with this litellm:.. as the namespace

Why? Reduce number of redis GET requests. This improved latency by 46% in prod load tests.

Usage

litellm_settings:
  cache: true
  cache_params:
    type: redis
    ... # remaining redis args (host, port, etc.)
  callbacks: ["batch_redis_requests"] # 👈 KEY CHANGE!

SEE CODE

Supported cache_params on proxy config.yaml​

cache_params:
  # ttl 
  ttl: Optional[float]
  default_in_memory_ttl: Optional[float]
  default_in_redis_ttl: Optional[float]

  # Type of cache (options: "local", "redis", "s3")
  type: s3

  # List of litellm call types to cache for
  # Options: "completion", "acompletion", "embedding", "aembedding"
  supported_call_types: ["acompletion", "atext_completion", "aembedding", "atranscription"]
                      # /chat/completions, /completions, /embeddings, /audio/transcriptions

  # Redis cache parameters
  host: localhost  # Redis server hostname or IP address
  port: "6379"  # Redis server port (as a string)
  password: secret_password  # Redis server password
  namespace: Optional[str] = None,
  

  # S3 cache parameters
  s3_bucket_name: your_s3_bucket_name  # Name of the S3 bucket
  s3_region_name: us-west-2  # AWS region of the S3 bucket
  s3_api_version: 2006-03-01  # AWS S3 API version
  s3_use_ssl: true  # Use SSL for S3 connections (options: true, false)
  s3_verify: true  # SSL certificate verification for S3 connections (options: true, false)
  s3_endpoint_url: https://s3.amazonaws.com  # S3 endpoint URL
  s3_aws_access_key_id: your_access_key  # AWS Access Key ID for S3
  s3_aws_secret_access_key: your_secret_key  # AWS Secret Access Key for S3
  s3_aws_session_token: your_session_token  # AWS Session Token for temporary credentials

Advanced - user api key cache ttl​

Configure how long the in-memory cache stores the key object (prevents db requests)

general_settings:
  user_api_key_cache_ttl: <your-number> #time in seconds

By default this value is set to 60s.