from kafka import KafkaClient, SimpleConsumer
from sys import argv
kafka = KafkaClient("10.0.1.100:6667")
consumer = SimpleConsumer(kafka, "my-group", argv[1])
consumer.max_buffer_size=0
consumer.seek(0,2)
for message in consumer:
print("OFFSET: "+str(message[0])+"\t MSG: "+str(message[1][3]))
Max Buffer Size
There are two lines I wanted to focus on in particular. The first is the “max_buffer_size” setting:
consumer.max_buffer_size=0
When subscribing to a topic with a high level of messages that have not been received before, the consumer/client can max out and fail. Setting an infinite buffer size (zero) allows it to take everything that is available.
If you kill and restart the script it will continue where it last left off, at the last offset that was received. This is pretty cool but in some environments it has some trouble, so I changed the default by adding another line.
Offset Out of Range Error
As I regularly kill the servers running Kafka and the producers feeding it (yes, just for fun), things sometimes go a bit crazy, not entirely sure why but I got the error:
kafka.common.OffsetOutOfRangeError: FetchResponse(topic='my_messages', partition=0, error=1, highwaterMark=-1, messages=)
To fix it I added the “seek” setting:
consumer.seek(0,2)
