我的堆栈是uwsgi与gevents.我试图用装饰器包装我的api端点,将所有请求数据(url,方法,正文和响应)推送到kafka主题,但它不起作用.我的理论是因为我正在使用gevents,并且我试图在异步模式下运行它们,实际推送到kafka的异步线程无法与gevents一起运行.并且如果我尝试使方法同步,那么它也不起作用,它在产品工作者中死亡,即在产生调用后永远不会返回.虽然这两种方法在python shell上运行良好,但是我在线程上运行uwsgi.
按照示例代码:
1.使用kafka-python(异步)
try:
kafka_producer = KafkaProducer(bootstrap_servers=KAFKAHOST.split(','))
except NoBrokersAvailable:
logger.info(u'Kafka Host not available: {}'.format(KAFKAHOST))
kafka_producer = None
def send_message_to_kafka(topic, key, message):
"""
:param topic: topic name
:param key: key to decide partition
:param message: json serializable object to send
:return:
"""
if not kafka_producer:
logger.info(u'Kafka Host not available: {}'.format(KAFKAHOST))
return
data = json.dumps(message)
try:
start = time.time()
kafka_producer.send(topic, key=str(key), value=data)
logger.info(u'Time take to push to Kafka: {}'.format(time.time() - start))
except KafkaTimeoutError as e:
logger.info(u'Message not sent: {}'.format(KAFKAHOST))
logger.info(e)
pass
except Exception as e:
logger.info(u'Message not sent: {}'.format(KAFKAHOST))
logger.exception(e)
pass
>使用py-kafka(同步):
try:
client = KafkaClient(hosts=KAFKAHOST)
except Exception as e:
logger.info(u'Kafka Host Not Found: {}'.format(KAFKAHOST))
client = None
def send_message_to_kafka(topic, key, message):
"""
:param topic: topic name
:param key: key to decide partition
:param message: json serializable object to send
:return:
"""
if not client:
logger.info(u'Kafka Host is None')
return
data = json.dumps(message)
try:
start = time.time()
topic = client.topics[topic]
with topic.get_sync_producer() as producer:
producer.produce(data, partition_key='{}'.format(key))
logger.info(u'Time take to push to Kafka: {}'.format(time.time() - start))
except Exception as e:
logger.exception(e)
pass
最佳答案:
我对pykafka有更多经验,所以我可以回答那一节. pykafka使用可插入的线程处理程序,并且内置了gevent支持.您需要使用use_greenlets = True来实例化KafkaClient. Docs here
关于你的方法的其他想法.为每条消息创建一个新的主题对象和生产者是非常昂贵的.最好创建一次并重用.
# setup once
client = KafkaClient(hosts=KAFKAHOST, use_greenlets=True)
topic = client.topics[topic]
producer = topic.get_sync_producer()
def send_message_to_kafka(producer, key, message):
"""
:param producer: pykafka producer
:param key: key to decide partition
:param message: json serializable object to send
:return:
"""
data = json.dumps(message)
try:
start = time.time()
producer.produce(data, partition_key='{}'.format(key))
logger.info(u'Time take to push to Kafka: {}'.format(time.time() - start))
except Exception as e:
logger.exception(e)
pass # for at least once delivery you will need to catch network errors and retry.
最后,kafka从批处理和压缩中获得了所有速度.使用同步生成器可以防止客户端利用这些功能.它会工作,但速度较慢,占用空间更多.某些应用程序需要同步,但如果您遇到性能瓶颈,则可能需要将应用程序重新考虑为批处理消息.