How does Kafka define partition key?

As I mentioned in the part about the Kafka record, the key is used for partitioning. By default, Kafka producer relies on the key of the record to decide to which partition to write the record. For two records with the same key, the producer will always choose the same partition.

How does Kafka write to partition?

kafka producers write cadence and partitioning of records the producers get to configure their consistency/durability level (ack=0, ack=all, ack=1), which we will cover later. producers pick the partition such that record/messages go to a given partition based on the data.

What is true regarding partitions in Kafka?

Partitions are the main concurrency mechanism in Kafka. A topic is divided into 1 or more partitions, enabling producer and consumer loads to be scaled. Specifically, a consumer group supports as many consumers as partitions for a topic.

What is partition offset in Kafka?

Kafka maintains a numerical offset for each record in a partition. This offset acts as a unique identifier of a record within that partition, and also denotes the position of the consumer in the partition.

How does Kafka determine partition count?

Therefore, in general, the more partitions there are in a Kafka cluster, the higher the throughput one can achieve. A rough formula for picking the number of partitions is based on throughput. You measure the throughout that you can achieve on a single partition for production (call it p) and consumption (call it c).

How many Kafka partitions is too many?

Do not set up too many partitions The load on the CPU will also get higher with more partitions since Kafka needs to keep track of all of the partitions. More than 50 partitions for a topic are rarely recommended good practice.

How do you determine the number of partitions for a topic?

The unit of parallelism is the partition, so if you know the average processing time per message, then you should be able to calculate the number of partitions required to keep up. For example if each message takes 100ms to process and you receive 5k a second then you’ll need at least 50 partitions.

Do Kafka partitions have the same data?

Kafka sends all messages from a particular producer to the same partition, storing each message in the order it arrives. As Kafka adds each record to a partition, it assigns a unique sequential ID called an offset.

What is rebalancing in Kafka?

Rebalancing is the process where a group of consumer instances (belonging to the same group) co-ordinate to own a mutually exclusive set of partitions of topics that the group is subscribed to.

How do you choose the number of partitions in Kafka topic?

How to guarantee order in Kafka partition?

Lets first try and understand the problem statement. Let us assume we have a topic where messages are sent and there is a consumer who is consuming these messages.

What is the difference between Kafka and Cassandra?

Cassandra belongs to “Databases” category of the tech stack, while Kafka can be primarily classified under “Message Queue”. “Distributed”, “High performance” and “High availability” are the key factors why developers consider Cassandra; whereas “High-throughput”, “Distributed” and “Scalable” are the primary reasons why Kafka is favored.

What is the actual use of Kafka?

Messaging. Kafka works well as a replacement for a more traditional message broker.

What are some alternatives to Kafka?

Well, there is no system today built with the same concept which Kafka uses. And Kafka is much more than a message broker. So, considering you want an alternative message broker then there are lot of alternative such as ActiveMQ, ZeroMQ, RabbitMQ etc.