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Caching

Cache LLM Responses

LiteLLM supports:

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

Quick Start - Redis, s3 Cache, Semantic Cache

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"

and keys will be stored like:

litellm_caching:<hash>

TTL

litellm_settings:
cache: true
cache_params: # set cache params for redis
type: redis
ttl: 600 # will be cached on redis for 600s

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

Using Caching - /chat/completions

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
}'

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

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", "completion", "embedding", "aembedding"] # defaults to all litellm call types

Turn on / off caching per request.

The proxy support 3 cache-controls:

  • ttl: Optional(int) - Will cache the response for the user-defined amount of time (in seconds).
  • s-maxage: Optional(int) Will only accept cached responses that are within user-defined range (in seconds).
  • no-cache: Optional(bool) Will not return a cached response, but instead call the actual endpoint.
  • no-store: Optional(bool) Will not cache the response.

Let us know if you need more

Turn off caching

import os
from openai import OpenAI

client = OpenAI(
# This is the default and can be omitted
api_key=os.environ.get("OPENAI_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: {
"no-cache": True # will not return a cached response
}
}
)

Turn on caching

import os
from openai import OpenAI

client = OpenAI(
# This is the default and can be omitted
api_key=os.environ.get("OPENAI_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: {
"ttl": 600 # caches response for 10 minutes
}
}
)
import os
from openai import OpenAI

client = OpenAI(
# This is the default and can be omitted
api_key=os.environ.get("OPENAI_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: {
"s-maxage": 600 # only get responses cached within last 10 minutes
}
}
)

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,
}

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:
# 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:
- completion
- acompletion
- embedding
- aembedding

# 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

# 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.