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#!/usr/bin/env python
# flake8: noqa
# Copyright 2019 Confluent Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# Companion code to the blog post "Integrating Kafka With Python
# Asyncio Web Applications"
# https://www.confluent.io/blog/kafka-python-asyncio-integration/
#
# Example Siege [https://github.com/JoeDog/siege] test:
# $ siege -c 400 -r 200 'http://localhost:8000/items1 POST {"name":"testuser"}'
import asyncio
import confluent_kafka
from confluent_kafka import KafkaException
from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
from time import time
from threading import Thread
import uvicorn
class AIOProducer:
def __init__(self, configs, loop=None):
self._loop = loop or asyncio.get_event_loop()
self._producer = confluent_kafka.Producer(configs)
self._cancelled = False
self._poll_thread = Thread(target=self._poll_loop)
self._poll_thread.start()
def _poll_loop(self):
while not self._cancelled:
self._producer.poll(0.1)
def close(self):
self._cancelled = True
self._poll_thread.join()
def produce(self, topic, value):
"""
An awaitable produce method.
"""
result = self._loop.create_future()
def ack(err, msg):
if err:
self._loop.call_soon_threadsafe(result.set_exception, KafkaException(err))
else:
self._loop.call_soon_threadsafe(result.set_result, msg)
self._producer.produce(topic, value, on_delivery=ack)
return result
def produce2(self, topic, value, on_delivery):
"""
A produce method in which delivery notifications are made available
via both the returned future and on_delivery callback (if specified).
"""
result = self._loop.create_future()
def ack(err, msg):
if err:
self._loop.call_soon_threadsafe(
result.set_exception, KafkaException(err))
else:
self._loop.call_soon_threadsafe(
result.set_result, msg)
if on_delivery:
self._loop.call_soon_threadsafe(
on_delivery, err, msg)
self._producer.produce(topic, value, on_delivery=ack)
return result
class Producer:
def __init__(self, configs):
self._producer = confluent_kafka.Producer(configs)
self._cancelled = False
self._poll_thread = Thread(target=self._poll_loop)
self._poll_thread.start()
def _poll_loop(self):
while not self._cancelled:
self._producer.poll(0.1)
def close(self):
self._cancelled = True
self._poll_thread.join()
def produce(self, topic, value, on_delivery=None):
self._producer.produce(topic, value, on_delivery=on_delivery)
config = {"bootstrap.servers": "localhost:9092"}
app = FastAPI()
class Item(BaseModel):
name: str
aio_producer = None
producer = None
@app.on_event("startup")
async def startup_event():
global producer, aio_producer
aio_producer = AIOProducer(config)
producer = Producer(config)
@app.on_event("shutdown")
def shutdown_event():
aio_producer.close()
producer.close()
@app.post("/items1")
async def create_item1(item: Item):
try:
result = await aio_producer.produce("items", item.name)
return {"timestamp": result.timestamp()}
except KafkaException as ex:
raise HTTPException(status_code=500, detail=ex.args[0].str())
cnt = 0
def ack(err, msg):
global cnt
cnt = cnt + 1
@app.post("/items2")
async def create_item2(item: Item):
try:
aio_producer.produce2("items", item.name, on_delivery=ack)
return {"timestamp": time()}
except KafkaException as ex:
raise HTTPException(status_code=500, detail=ex.args[0].str())
@app.post("/items3")
async def create_item3(item: Item):
try:
producer.produce("items", item.name, on_delivery=ack)
return {"timestamp": time()}
except KafkaException as ex:
raise HTTPException(status_code=500, detail=ex.args[0].str())
@app.post("/items4")
async def create_item4(item: Item):
try:
producer.produce("items", item.name)
return {"timestamp": time()}
except KafkaException as ex:
raise HTTPException(status_code=500, detail=ex.args[0].str())
@app.post("/items5")
async def create_item5(item: Item):
return {"timestamp": time()}
if __name__ == '__main__':
uvicorn.run(app, host='127.0.0.1', port=8000)
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