Reading from Kafka with Spark in Apache Spark - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Apache Kafka used for in data processing?

Apache Kafka is a system that lets you send and receive streams of data in real time. It works like a messaging service where data is published and consumed continuously.

beginner

How does Spark connect to Kafka to read data?

Spark uses a special connector called the Kafka source. It reads data from Kafka topics as a stream or batch by specifying Kafka servers and topics in the Spark read options.

beginner

What is the role of 'subscribe' option when reading from Kafka in Spark?

The 'subscribe' option tells Spark which Kafka topic(s) to listen to for incoming data. You can list one or more topics separated by commas.

intermediate

What data format does Spark receive from Kafka by default?

Spark receives Kafka data as binary key and value columns. You often need to convert or decode these bytes into readable strings or structured data.

intermediate

Why is it important to set 'startingOffsets' when reading from Kafka with Spark?

The 'startingOffsets' option controls where Spark starts reading data in Kafka. For example, 'earliest' reads from the oldest data, and 'latest' reads only new data. This helps control what data you process.

Which Spark method is used to read data from Kafka?

A spark.read.format("kafka")

B spark.read.kafka()

C spark.readStream.kafka()

D spark.kafka.read()

To read from Kafka, you use spark.read.format("kafka") for batch or spark.readStream.format("kafka") for streaming.

What does the 'subscribe' option specify in Spark Kafka reading?

A Data format

B Kafka broker addresses

C Starting offset position

D Kafka topic names

The 'subscribe' option tells Spark which Kafka topic(s) to read from.

What data type are Kafka messages received as in Spark by default?

A String

B Binary

C Integer

D JSON

Kafka messages come as binary data in Spark and need decoding.

Which option controls where Spark starts reading Kafka data?

A subscribe

B kafka.bootstrap.servers

C startingOffsets

D group.id

'startingOffsets' sets the position to start reading from Kafka.

To read Kafka data as a continuous stream in Spark, which method is used?

A spark.readStream.format("kafka")

B spark.read.format("kafka")

C spark.kafka.stream()

D spark.stream.read()

spark.readStream.format("kafka") reads Kafka data as a streaming source.

Explain how to set up Spark to read data from a Kafka topic.

Think about the options needed to connect and select data from Kafka.

Describe how Kafka data appears in Spark and what you need to do to use it.

Consider the data type Spark receives and how to make it readable.