sglang0.4.5.post1/python/sglang/srt/disaggregation/mini_lb.py

286 lines
10 KiB
Python

"""
Minimal HTTP load balancer for prefill and decode servers for testing purpose.
"""
import asyncio
import random
import urllib
from itertools import chain
import aiohttp
import orjson
import uvicorn
from fastapi import FastAPI, HTTPException
from fastapi.responses import ORJSONResponse, Response, StreamingResponse
class MiniLoadBalancer:
def __init__(self, prefill_servers, decode_servers):
self.prefill_servers = prefill_servers
self.decode_servers = decode_servers
def select_pair(self):
return random.choice(self.prefill_servers), random.choice(self.decode_servers)
async def generate_request(self, request_data):
prefill_server, decode_server = self.select_pair()
# Parse and transform prefill_server
parsed_url = urllib.parse.urlparse(prefill_server)
hostname = parsed_url.hostname
bootstrap_host = f"{hostname}"
modified_request = request_data.copy()
modified_request.update(
{
"bootstrap_host": bootstrap_host,
"bootstrap_room": random.randint(0, 2**63 - 1),
}
)
async with aiohttp.ClientSession() as session:
# Create the tasks
tasks = [
session.post(f"{prefill_server}/generate", json=modified_request),
session.post(f"{decode_server}/generate", json=modified_request),
]
prefill_response = None
decode_response = None
# Process responses as they arrive
for i, response in enumerate(asyncio.as_completed(tasks)):
response = await response
# Check if this is the prefill or decode response based on order created
if i == 0: # First completed task
if str(response.url).startswith(prefill_server):
prefill_response = response
if response.status != 200:
raise HTTPException(
status_code=response.status,
detail=f"Prefill server error: Status {response.status} Details: {await response.text()}",
)
else:
decode_response = response
if response.status != 200:
raise HTTPException(
status_code=response.status,
detail=f"Decode server error: Status {response.status} Details: {await response.text()}",
)
else: # Second completed task
if str(response.url).startswith(prefill_server):
prefill_response = response
else:
decode_response = response
if response.status != 200:
raise HTTPException(
status_code=response.status,
detail=f"{'Prefill' if str(response.url).startswith(prefill_server) else 'Decode'} server error: Status {response.status} Details: {await response.text()}",
)
return await decode_response.json()
app = FastAPI()
load_balancer = None
@app.get("/health")
async def health_check():
return Response(status_code=200)
@app.get("/health_generate")
async def health_check():
prefill_servers, decode_servers = (
load_balancer.prefill_servers,
load_balancer.decode_servers,
)
async with aiohttp.ClientSession() as session:
# Create the tasks
tasks = []
for server in chain(prefill_servers, decode_servers):
tasks.append(session.post(f"{server}/health_generate"))
for i, response in enumerate(asyncio.as_completed(tasks)):
await response
return Response(status_code=200)
@app.post("/flush_cache")
async def flush_cache():
prefill_servers, decode_servers = (
load_balancer.prefill_servers,
load_balancer.decode_servers,
)
async with aiohttp.ClientSession() as session:
# Create the tasks
tasks = []
for server in chain(prefill_servers, decode_servers):
tasks.append(session.post(f"{server}/flush_cache"))
for i, response in enumerate(asyncio.as_completed(tasks)):
await response
return Response(status_code=200)
@app.get("/get_server_info")
async def get_server_info():
prefill_servers, decode_servers = (
load_balancer.prefill_servers,
load_balancer.decode_servers,
)
prefill_infos = []
decode_infos = []
async with aiohttp.ClientSession() as session:
for server in chain(prefill_servers):
server_info = await session.get(f"{server}/get_server_info")
prefill_infos.append(await server_info.json())
for server in chain(decode_servers):
server_info = await session.get(f"{server}/get_server_info")
decode_infos.append(await server_info.json())
return {"prefill": prefill_infos, "decode": decode_infos}
@app.get("/get_model_info")
async def get_model_info():
# Dummy model information
model_info = {
"model_path": "/path/to/dummy/model",
"tokenizer_path": "/path/to/dummy/tokenizer",
"is_generation": True,
"preferred_sampling_params": {"temperature": 0.7, "max_new_tokens": 128},
}
return ORJSONResponse(content=model_info)
@app.post("/generate")
async def handle_generate_request(request_data: dict):
prefill_server, decode_server = load_balancer.select_pair()
# Parse and transform prefill_server for bootstrap data
parsed_url = urllib.parse.urlparse(prefill_server)
hostname = parsed_url.hostname
modified_request = request_data.copy()
modified_request.update(
{
"bootstrap_host": hostname,
"bootstrap_room": random.randint(0, 2**63 - 1),
}
)
# Check if streaming is requested
if request_data.get("stream", False):
async def stream_results():
async with aiohttp.ClientSession(
timeout=aiohttp.ClientTimeout(total=3600)
) as session:
try:
# Create the tasks
tasks = [
session.post(
f"{prefill_server}/generate", json=modified_request
),
session.post(
f"{decode_server}/generate", json=modified_request
),
]
prefill_response = None
decode_response = None
# Process responses as they arrive
for i, response_task in enumerate(asyncio.as_completed(tasks)):
response = await response_task
# Check the response immediately
if str(response.url).startswith(prefill_server):
prefill_response = response
if response.status != 200:
error_msg = {
"error": {
"message": f"Prefill server error: Status {response.status}, Details: {await response.text()}"
}
}
yield b"data: " + orjson.dumps(
error_msg, option=orjson.OPT_NON_STR_KEYS
) + b"\n\n"
return
else:
decode_response = response
if response.status != 200:
error_msg = {
"error": {
"message": f"Decode server error: Status {response.status}"
}
}
yield b"data: " + orjson.dumps(
error_msg, option=orjson.OPT_NON_STR_KEYS
) + b"\n\n"
return
# Stream successful decode server response
async for line in decode_response.content:
yield line
yield b"data: [DONE]\n\n"
except Exception as e:
error_msg = {
"error": {"message": f"Stream processing error: {str(e)}"}
}
yield b"data: " + orjson.dumps(
error_msg, option=orjson.OPT_NON_STR_KEYS
) + b"\n\n"
return StreamingResponse(
stream_results(),
media_type="text/event-stream",
)
# Non-streaming case
result = await load_balancer.generate_request(request_data)
return ORJSONResponse(content=result)
@app.get("/v1/models")
async def get_models():
prefill_server = load_balancer.prefill_servers[0] # Get the first prefill server
async with aiohttp.ClientSession() as session:
try:
response = await session.get(f"{prefill_server}/v1/models")
if response.status != 200:
raise HTTPException(
status_code=response.status,
detail=f"Prefill server error: Status {response.status}",
)
return ORJSONResponse(content=await response.json())
except Exception as e:
raise HTTPException(status_code=500, detail=str(e))
def run(prefill_addrs, decode_addrs, host, port):
global load_balancer
load_balancer = MiniLoadBalancer(prefill_addrs, decode_addrs)
uvicorn.run(app, host=host, port=port)
if __name__ == "__main__":
import argparse
parser = argparse.ArgumentParser(description="Mini Load Balancer Server")
parser.add_argument(
"--prefill", required=True, help="Comma-separated URLs for prefill servers"
)
parser.add_argument(
"--decode", required=True, help="Comma-separated URLs for decode servers"
)
parser.add_argument(
"--host", default="0.0.0.0", help="Host to bind the server (default: 0.0.0.0)"
)
parser.add_argument(
"--port", type=int, default=8000, help="Port to bind the server (default: 8000)"
)
args = parser.parse_args()
run(args.prefill.split(","), args.decode.split(","), args.host, args.port)