Apache Kafka using Keys for Partition

1. How does Kafka choose partition key?
2. How does Kafka partition work?
3. How do you define a partitioning key?
4. What is the use of key in Kafka?
5. Does Kafka key need to be unique?
6. How many Kafka partitions is too many?
7. How many Kafka partitions do I need?
8. Is Kafka pull or push?
9. Can we increase Kafka partitions?
10. How do I choose my Cassandra partition key?
11. Is partition key a primary key?
12. What is DynamoDB partition key?

How does Kafka choose 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 partition work?

Partitions are spread across the nodes in a Kafka cluster. ... Partitions can have copies to increase durability and availability and enable Kafka to failover to a broker with a replica of the partition if the broker with the leader partition fails. This is called the Replication Factor and can be 1 or more.

How do you define a partitioning key?

The partitioning key consists of one or more columns that determine the partition where each row is stored. Oracle automatically directs insert, update, and delete operations to the appropriate partition with the partitioning key.

What is the use of key in Kafka?

The key is commonly used for data about the message and the value is the body of the message. Kafka uses the terms record and message interchangeably.

Does Kafka key need to be unique?

Optional Kafka event key. If configured, the event key must be unique and can be extracted from the event using a format string. i believe the documentation is incorrect, FYI: I set the following key and it works fine.

How many Kafka partitions is too many?

As guideline for optimal performance, you should not have more than 4000 partitions per broker and not more than 200,000 partitions in a cluster.

How many Kafka partitions do I need?

For most implementations you want to follow the rule of thumb of 10 partitions per topic, and 10,000 partitions per Kafka cluster. Going beyond that amount can require additional monitoring and optimization.

Is Kafka pull or push?

With Kafka consumers pull data from brokers. Other systems brokers push data or stream data to consumers. ... Since Kafka is pull-based, it implements aggressive batching of data. Kafka like many pull based systems implements a long poll (SQS, Kafka both do).

Can we increase Kafka partitions?

Apache Kafka provides us with alter command to change Topic behaviour and add/modify configurations. We will be using alter command to add more partitions to an existing Topic. Note: While Kafka allows us to add more partitions, it is NOT possible to decrease number of partitions of a Topic.

How do I choose my Cassandra partition key?

determine how the data is partitioned. determine what is phisically stored in a single row.
...
b1, b2, ... are column family fields used to cluster a row key in order to:

1. create logical sets inside a single row.
2. allow more flexible search schemes such as range range.
3. referred as column key or cluster key.

Is partition key a primary key?

The partition key is responsible for distributing data among nodes. A partition key is the same as the primary key when the primary key consists of a single column. Partition keys belong to a node. Cassandra is organized into a cluster of nodes, with each node having an equal part of the partition key hashes.

What is DynamoDB partition key?

Partition key – A simple primary key, composed of one attribute known as the partition key. DynamoDB uses the partition key's value as input to an internal hash function. The output from the hash function determines the partition (physical storage internal to DynamoDB) in which the item will be stored.