Question: Can Kafka Lose Messages?

How do I stop duplicate messages in Kafka?

At-least-once Kafka Consumer (One or More Message Deliveries, Duplicate Possible)Set ‘enable.

auto.

commit’ to false or.Set ‘enable.

auto.

Consumer should now then take control of the message offset commits to Kafka by making the following call consumer.

commitSync();.

Is Kafka a data store?

Kafka can be used for storing data. … Kafka, as an event streaming platform, works with streaming data. At the same time, Kafka can store data for some time before removing it. This means that Kafka is different from traditional message queues that drop messages as soon as they are read by the consumer.

What happens if zookeeper goes down in Kafka?

For example, if you lost the Kafka data in ZooKeeper, the mapping of replicas to Brokers and topic configurations would be lost as well, making your Kafka cluster no longer functional and potentially resulting in total data loss.

How does Kafka prevent data loss?

Instead of this, I will try to describe the most important configuration to prevent data loss in Kafka.Producer Acknowledgements. … Producer retries. … Replication. … Minimal in-sync replicas. … Unclean leader election. … Consumer auto commit. … Messages not synced to disk. … Summary.

Can I use Kafka as database?

The main idea behind Kafka is to continuously process streaming data; with additional options to query stored data. Kafka is good enough as database for some use cases. However, the query capabilities of Kafka are not good enough for some other use cases.

Is Kafka guaranteed delivery?

Now, Kafka provides “at-least-once” delivery guarantees, as each record will likely be delivered one time but in a failure case, data could be duplicated. … Processing in batches of records is available in Kafka as well.

Is Kafka a message bus?

Kafka is a message bus optimized for high-ingress data streams and replay. Kafka can be seen as a durable message broker where applications can process and re-process streamed data on disk.”

Which of the following is guaranteed by Kafka?

17. Which of the following is guaranteed by Kafka? A consumer instance gets the messages in the same order as they are produced. A consumer instance is guaranteed to get all the messages produced.

Which one is a messaging system in Kafka?

Which one functions as a messaging system? Kafka Based on the classification of messages Kafka categorizes messages into Topics In Kafka, the communication between the clients and servers is done with —– Protocol. TCP Which concept of Kafka helps scale processing and multi-subscription.

How does Kafka handle duplicate messages?

How do I get exactly-once messaging from Kafka?Use a single-writer per partition and every time you get a network error check the last message in that partition to see if your last write succeeded.Include a primary key (UUID or something) in the message and deduplicate on the consumer.

What happens when Kafka broker goes down?

Kafka does not create a new replica when a broker goes down. … If the offline broker was a follower, it will be marked a out of sync by the leader. When restarting the broker, it will try to get back in sync. Once done, whether it stays a follower or becomes the leader depends if it is the prefered replica.

Is Kafka at least once?

Introduction To Message Delivery Semantics In Kafka They are: At most once, at least once, exactly once. In at most once delivery, the message is either delivered or not delivered. This delivery semantic is suited for use cases where losing some messages do not affect the result of processing the complete data.

Why zookeeper is needed for Kafka?

Zookeeper keeps track of status of the Kafka cluster nodes and it also keeps track of Kafka topics, partitions etc. Zookeeper it self is allowing multiple clients to perform simultaneous reads and writes and acts as a shared configuration service within the system.

Where are Kafka messages stored?

Kafka stores all the messages with the same key into a single partition. Each new message in the partition gets an Id which is one more than the previous Id number. This Id number is also called as the Offset . So, the first message is at ‘offset’ 0, the second message is at offset 1 and so on.

How long does Kafka keep data?

The Kafka cluster retains all published messages—whether or not they have been consumed—for a configurable period of time. For example if the log retention is set to two days, then for the two days after a message is published it is available for consumption, after which it will be discarded to free up space.

How do I know if Kafka is running?

I would say that another easy option to check if a Kafka server is running is to create a simple KafkaConsumer pointing to the cluste and try some action, for example, listTopics(). If kafka server is not running, you will get a TimeoutException and then you can use a try-catch sentence.