Merge pull request confluentinc#716 from confluentinc/asyncioeg

mhowlett · web-flow · commit fe8596887f62 · 2019-12-05T09:10:06.000-08:00
Added asyncio producer example
diff --git a/examples/asyncio.py b/examples/asyncio.py
@@ -0,0 +1,178 @@
+# 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/[path-to-blog-post]
+
+# 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)
