在特定时间段内从kafka获取结果

Question

这是我的代码，它使用kafka-python 。

now = datetime.now()
month_ago = now - relativedelta(month=1)
topic = 'some_topic_name'
consumer = KafkaConsumer(topic, bootstrap_servers=PROD_KAFKA_SERVER,
                         security_protocol=PROTOCOL,
                         group_id=GROUP_ID,
                         enable_auto_commit=False,
                         sasl_mechanism=SASL_MECHANISM, sasl_plain_username=SASL_USERNAME,
                         sasl_plain_password=SASL_PASSWORD)


for msg in consumer:
    print(msg)

我想循环从now到month_ago之间的主题获取结果。 我怎样才能做到这一点？

谢谢你的帮助！

Answer 1

获取分配给您的消费者的主题分区：

partitions = consumer.assignment()

按日期时间获取分区的偏移量：

month_ago_timestamp = int(month_ago.timestamp() * 1000)
partition_to_timestamp = {part: month_ago_timestamp for part in partitions}
mapping = consumer.offsets_for_times(partition_to_timestamp)

寻找偏移量的分区：

for partition, offset_and_timestamp in partition_to_offset_and_timestamp.items():
    consumer.seek(partition, offset_and_timestamp[0])

警告，在缺少主题、缺少分区或没有时间戳的消息等情况下，消费者可以返回无、设置为零或无限期阻塞

Answer 2

最后，我这样做了 :) 我的代码如下所示：

topic = 'some_topic_name'
consumer = KafkaConsumer(bootstrap_servers=PROD_KAFKA_SERVER,
                         security_protocol=PROTOCOL,
                         group_id=GROUP_ID,
                         sasl_mechanism=SASL_MECHANISM, sasl_plain_username=SASL_USERNAME,
                         sasl_plain_password=SASL_PASSWORD)

month_ago = (datetime.now() - relativedelta(months=1)).timestamp()
topic_partition = TopicPartition(topic, 0)
assigned_topic = [topic_partition]
consumer.assign(assigned_topic)

partitions = consumer.assignment()
partition_to_timestamp = {part: int(month_ago * 1000) for part in partitions}
end_offsets = consumer.end_offsets(list(partition_to_timestamp.keys()))

mapping = consumer.offsets_for_times(partition_to_timestamp)
for partition, ts in mapping.items():
    end_offset = end_offsets.get(partition)
    consumer.seek(partition, ts[0])
    for msg in consumer:
        value = json.loads(msg.value.decode('utf-8'))
        # do something
        if msg.offset == end_offset - 1:
            consumer.close()
            break