我刚接触Python并开始使用Kafka。因此,我设置了一个Kafka经纪人,并尝试使用confluent-kafka与它进行通信。 我已经能够使用它生成和使用简单的消息,但是,我有一些django对象,我需要对其进行序列化并将其发送给ti kafka。
以前,我使用的是kafka-python,可以在其上发送和使用json消息,但是我遇到了一些奇怪的问题。
#Producer.py
def send_message(topic,message) :
try :
try :
p.produce(topic,message,callback=delivery_callback)
except BufferError as b :
sys.stderr.write('%% Local producer queue is full (%d messages awaiting delivery): try again\n' %len(p))
# Serve delivery callback queue.
# NOTE: Since produce() is an asynchronous API this poll() call
# will most likely not serve the delivery callback for the
# last produce()d message.
p.poll(0)
# Wait until all messages have been delivered
sys.stderr.write('%% Waiting for %d deliveries\n' % len(p))
p.flush()
except Exception as e :
import traceback
print(traceback.format_exc())
#Consumer.py
conf = {'bootstrap.servers': "localhost:9092", 'group.id': 'test', 'session.timeout.ms': 6000,
'auto.offset.reset': 'earliest'}
c = Consumer(conf)
c.subscribe(["mykafka"])
try:
while True:
msg = c.poll(timeout=1.0)
if msg is None:
continue
if msg.error():
raise KafkaException(msg.error())
else:
sys.stderr.write('%% %s [%d] at offset %d with key %s:\n' %
(msg.topic(), msg.partition(), msg.offset(),
str(msg.key())))
print(msg.value())
except Exception as e:
import traceback
print(traceback.format_exc())
finally:
c.close()
我像这样序列化我的Django模型对象:
from django.core import serializers
# assuming obj is a model instance
serialized_obj = serializers.serialize('json', [ obj, ])
那么我需要在生产者和消费者中进行哪些更改以产生和使用json消息?
答案 0 :(得分:0)
尝试制作人
with ... <the same as above>
select id from second_query
minus
select id from first_query
使用者,您会将字节序列化为一个字符串
send_message(topic, serialized_obj)
如果您需要json对象,则可以使用print(msg.value().decode('utf8'))