Based on your question clarification. A Kafka Consumer can read multiple messages at a time. But a Kafka Consumer doesn’t really read messages, its more correct to say a Consumer reads a certain number of bytes and then based on the size of the individual messages, that determines how many messages will be read. Reading … Read more
The Exception you are referring to Exception in thread “main” org.apache.kafka.clients.consumer.CommitFailedException: Commit cannot be completed since the group has already rebalanced and assigned the partitions to another member. This means that the time between subsequent calls to poll() was longer than the configured max.poll.interval.ms, which typically implies that the poll loop is spending too much … Read more
This post already has answers, but I am adding my view with a few pictures from Kafka Definitive Guide Before answering the questions, let’s look at an overview of producer components: 1. When a producer is producing a message – It will specify the topic it wants to send the message to, is that right? … Read more
In Kafka, the responsibility of what has been consumed is the responsibility of the consumer and this is also one of the main reasons why Kafka has such great horizontal scalability. Using the high level consumer API will automatically do this for you by committing consumed offsets in Zookeeper (or a more recent configuration option … Read more
I came across this question when trying to also consume from the __consumer_offsets topic. I managed to figure it out for different Kafka versions and thought I’d share what I’d found For Kafka 0.8.2.x Note: This uses Zookeeper connection #Create consumer config echo “exclude.internal.topics=false” > /tmp/consumer.config #Consume all offsets ./kafka-console-consumer.sh –consumer.config /tmp/consumer.config \ –formatter “kafka.server.OffsetManager\$OffsetsMessageFormatter” … Read more
It is a bit more complex than you described. The auto.offset.reset config kicks in ONLY if your consumer group does not have a valid offset committed somewhere (2 supported offset storages now are Kafka and Zookeeper), and it also depends on what sort of consumer you use. If you use a high-level java consumer then … Read more
Before KIP-62, there is only session.timeout.ms (ie, Kafka 0.10.0 and earlier). max.poll.interval.ms is introduced via KIP-62 (part of Kafka 0.10.1). KIP-62, decouples heartbeats from calls to poll() via a background heartbeat thread, allowing for a longer processing time (ie, time between two consecutive poll()) than heartbeat interval. Assume processing a message takes 1 minute. If … Read more