Steps to delete data inside the Kafka Topic on Windows? - apache-kafka

Question

I am working on Spring Batch and Apache Kafka Integration. Before posting the question I went over web : Is there a way to delete all the data from a topic or delete the topic before every run? to find out better solution, but did not find out.
I am using Kafka version 2.11.
I want to delete all data under the topic without stopping either Zookeeper or Kafka. How can we do that ?
Below commands causes lot of issues in windows
C:\kafka_2.11-2.3.1\bin\windows>kafka-topics.bat --zookeeper localhost:2181 --delete --topic customers
Topic customers is marked for deletion.
Note: This will have no impact if delete.topic.enable is not set to true.
C:\kafka_2.11-2.3.1\bin\windows>kafka-topics.bat --zookeeper localhost:2181 --delete --topic test
C:\kafka_2.11-2.3.1\bin\windows>kafka-console-consumer.bat --bootstrap-server localhost:9092 --topic customers --from-beginning
[2020-04-21 10:25:02,812] WARN [Consumer clientId=consumer-1, groupId=console-consumer-65075] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-21 10:25:04,886] WARN [Consumer clientId=consumer-1, groupId=console-consumer-65075] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-21 10:25:06,996] WARN [Consumer clientId=consumer-1, groupId=console-consumer-65075] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-21 10:25:09,267] WARN [Consumer clientId=consumer-1, groupId=console-consumer-65075] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
[2020-04-21 10:25:11,744] WARN [Consumer clientId=consumer-1, groupId=console-consumer-65075] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available. (org.apache.kafka.clients.NetworkClient)
Processed a total of 0 messages
Terminate batch job (Y/N)?
^C
C:\kafka_2.11-2.3.1\bin\windows>

Answer 1

I am using Kafka version 2.11.
There is no Kafka 2.11. Your command prompt says kafka_2.11-2.3.1: hence, you are using Kafka 2.3.1. The 2.11 part is the Scala version that was used during compilation.
Note: This will have no impact if delete.topic.enable is not set to true.
Did you check your broker configs if delete.topic.enable is set to true? If yes, you should be able to delete a topic without stopping ZK or the brokers. Note though, that deleting topics is async, i.e., when you command returns the topic is not deleted yet and it will take some time until the command is executed.