class IBUSStreamingDownsamplingConsumer:
LOG_FORMAT ="{} UTC_TS\t"\
"{}"
def __init__(self, kafkaHost, kafkaPort, tcpHost, tcpPort, group_id, topic,
logTopic, interval):
self.kafkaHost = kafkaHost
self.kafkaPort = kafkaPort
self.tcpHost = tcpHost
self.tcpPort = tcpPort
self.group_id = group_id
self.topic = topic
self.logTopic = logTopic
self.interval = int(interval)
self.consumer = KafkaConsumer(
topic,
bootstrap_servers=["{}:{}".format(kafkaHost, kafkaPort)],
group_id=group_id,
enable_auto_commit=False)
self.producer = KafkaProducer(
bootstrap_servers=["{}:{}".format(kafkaHost, kafkaPort)])
self.tcpWriter = None
def getTopicPartitions(self):
self.consumer.topics() #This ensures local cache is updated with
# information about partitions, offsets etc.
pids = self.consumer.partitions_for_topic(self.topic)
tps = [TopicPartition(self.topic, pid) for pid in pids]
return tps
def getTopicPartitionsCommittedPositions(self):
tps = self.getTopicPartitions()
ret = [(tp, self.consumer.committed(tp)) for tp in tps]
return ret
async def tcp_server_handler(self, reader, writer):
addr = str(writer.get_extra_info("socket").getpeername())
if self.tcpWriter is not None:
self.log("refused " + addr)
writer.write(b"Connection limit reached; connection refused.")
writer.close()
return
self.log("accepted " + addr)
self.tcpWriter = writer
t1 = asyncio.create_task(self.poll_from_Kafka(writer))
try:
while True:
data = await reader.read(1) # 1024*16 bytes
if not data:
break
except BrokenPipeError:
"""
Catches connecton reset by peer when we are sending the batched data,
which is also when we cannot check for reader. The broken connection
on the writer side will ultimately lead to BrokenPipeError on the
reader side. Hence
"""
pass
finally:
t1.cancel()
self.log("closed " + addr)
writer.close()
self.tcpWriter = None
async def poll_from_Kafka(self, writer):
while True:
prevPos = self.getTopicPartitionsCommittedPositions()
polled = self.consumer.poll(timeout_ms=1000)
records = [
record.value for recordList in polled.values()
for record in recordList
]
try:
for record in records:
writer.write(record)
await writer.drain()
except ConnectionResetError:
"""
The error is not thrown reliably. If a connection is broken, and
one try to
writer.write(record)
await writer.drain()
This error may not manifest. It is thrown more often when one try
to repeatedly write to and drain a broken connection.
"""
print("Last batch not fully sent, not commited.")
for tp, pos in prevPos:
self.consumer.seek(tp, pos)
break
else:
self.consumer.commit()
await asyncio.sleep(self.interval)
def log(self, msg):
self.producer.send( self.logTopic,
self.LOG_FORMAT.format( datetime.now().timestamp(),
msg
) \
.encode()
)
def cleanup(self):
self.log("shutdown")
self.consumer.close()
self.producer.flush()
self.producer.close()
def run(self):
self.log("running")
asyncio.run(self._async_run())
async def _async_run(self):
tcpServer = await asyncio.start_server(self.tcp_server_handler,
self.tcpHost, self.tcpPort)
await tcpServer.serve_forever()
def getMsgData(topic, group, result, maxsize):
try:
saveResult = SaveDataResult()
saveResult.guid = str(uuid.uuid4())
saveResult.CreateDate = datetime.datetime.now().strftime(
"%Y-%m-%d %H:%M:%S")
msgInfos = []
result.guid = saveResult.guid
result.topic_messages = []
consumer = KafkaConsumer(bootstrap_servers=tmpbootstrap_servers,
enable_auto_commit=False,
group_id=group)
# Get all partitions by topic
par = consumer.partitions_for_topic(topic)
now_count = 0
for p in par:
tp = TopicPartition(topic, p)
consumer.assign([tp])
print(tp)
info = MsgPartitionInfo()
# Get committed offset
print('start to get committed offset.....')
try:
committed = consumer.committed(tp) or 0
except Exception, e_commit:
print(str(e_commit))
# Move consumer to end to get the last position
consumer.seek_to_end(tp)
last_offset = consumer.position(tp)
# Move consumer to beginning to get the first position
consumer.seek_to_beginning()
now_offset = consumer.position(tp)
from_offset = committed
if from_offset is None:
from_offset = now_offset
if from_offset < now_offset:
from_offset = now_offset
info.partition_ID = tp.partition
info.get_last_offset = last_offset
msgInfos.append(info)
print("[%s] partition(%s) -> now:%s, last:%s, committed:%s" %
(tp.topic, tp.partition, now_offset, last_offset, committed))
# Get msg from position to offset
while (from_offset < last_offset) and (now_count < maxsize):
consumer.seek(tp, from_offset)
polldata = consumer.poll(100)
from_offset += 1
now_count += 1
print('now_count=' + str(now_count))
result.topic_messages.append(polldata[tp][0].value)
saveResult.MsgInfo = json.dumps(msgInfos,
default=encode_MsgPartitionInfo,
ensure_ascii=False)
print(saveResult.MsgInfo)
consumer.close()
saveResult.message = "Success"
saveResult.Code = 200
producer = KafkaProducer(bootstrap_servers=tmpbootstrap_servers)
producer.send(topic + "_log",
json.dumps(saveResult, default=encode_SaveDataResult))
producer.flush()
# https://github.com/cuyu/python-demo/blob/master/demo_kafka.py
_TOPIC_NAME = 'anomaly'
_BROKERS = ['localhost:9092'
] #['localhost.com:9092', 'systest-auto-deployer:9092']
_GROUP_ID = 'my_group'
consumer = KafkaConsumer(
group_id='ddd',
auto_offset_reset='smallest', #largest
enable_auto_commit=
False, ## true时，Consumer会在消费消息后将offset同步到zookeeper，这样当Consumer失败后，新的consumer就能从zookeeper获取最新的offset
bootstrap_servers=_BROKERS)
# consumer = KafkaConsumer(bootstrap_servers=_BROKERS)
consumer.assign([TopicPartition(_TOPIC_NAME, 0)])
tp = TopicPartition(_TOPIC_NAME, 0)
print(consumer.committed(TopicPartition(_TOPIC_NAME, 0)))
# consumer.subscribe(topics=[_TOPIC_NAME])
# # Subscribe to a regex topic pattern
# consumer.subscribe(pattern='^awesome.*')
print(consumer.topics())
# partition = TopicPartition(topic=_TOPIC_NAME, partition=consumer.partitions_for_topic(_TOPIC_NAME))
# consumer.seek_to_beginning()
# consumer.seek(TopicPartition(_TOPIC_NAME, 0), 0)
consumer.seek(tp, 50) # 10 stands for start consumer from 10th offset
a = []
for m in consumer:
if len(a) < 5:
print(m.offset)
a.append(m.offset)
# consumer.commit()
# else:
