{"id":7931,"date":"2022-01-25T14:56:50","date_gmt":"2022-01-25T14:56:50","guid":{"rendered":"https:\/\/www.npntraining.com\/blog\/?p=7931"},"modified":"2022-01-25T14:57:29","modified_gmt":"2022-01-25T14:57:29","slug":"kafka-hands-on-commands","status":"publish","type":"post","link":"https:\/\/www.npntraining.com\/blog\/kafka-hands-on-commands\/","title":{"rendered":"Kafka Commands"},"content":{"rendered":"

Kafka Commands<\/h1>\n

Starting Zookeeper & Kafka<\/h2>\n
[npntraining ~]$ cd \\opt\\kafka\\zookeeper-3.5.6-bin\\bin\n[npntraining ~]$ zkserver.sh<\/code><\/pre>\n
Starting Kafka<\/strong><\/p>\n
[npntraining ~]$ cd \\opt\\kafka\\kafka_2.12-2.4.0\\bin\\\n[npntraining ~]$ kafka-server-start.sh \\opt\\kafka\\kafka_2.12-2.4.0\\config\\server.properties<\/code><\/pre>\n
Kafka Topic<\/h2>\n
You can create a new Kafka topic named simple-producer-consumer<\/code> as follows:<\/p>\n
[npntraining ~]$ cd \\opt\\kafka\\kafka_2.12-2.4.0\\bin\\\n[npntraining ~]$ kafka-topics.sh --create --zookeeper localhost:2181 --partitions 1 --replication-factor 1 --topic simple-producer-consumer<\/code><\/pre>\n
List all topics<\/strong><\/p>\n
You can verify that the simple-producer-consumer<\/code> topic was successfully created by listing all available topics:<\/p>\n
[npntraining ~]$ kafka-topics.sh --list --zookeeper localhost:2181<\/code><\/pre>\n
Deleting Topic<\/strong><\/p>\n
You can delete a topic named simple-producer-consumer<\/code> as follows:<\/p>\n
[npntraining ~]$ kafka-topics.sh --delete --zookeeper localhost:2181 --topic simple-producer-consumer\n\n[npntraining ~]$ kafka-topics.sh --delete --bootstrap-server localhost:9092 --topic simple-producer-consumer<\/code><\/pre>\n
Describing Topic<\/strong><\/p>\n
You can find more details about a topic named simple-producer-consumer<\/code><\/p>\n
[npntraining ~]$ kafka-topics.sh --describe --bootstrap-server localhost:9092 --topic <topic-name> <\/code><\/pre>\n
Creating topic with multiple partitions<\/strong><\/p>\n
You can add more partitions as follows:<\/p>\n
[npntraining ~]$ kafka-topics.sh --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic simple-producer-consumer<\/code><\/pre>\n
Under-replicated partitions<\/strong><\/p>\n
You can see the under-replicated partitions for all topics as follows:<\/p>\n
[npntraining ~]$ kafka-topics.sh --zookeeper localhost:2181\/kafka-cluster --describe --under-replicated-partitions<\/code><\/pre>\n
Producing and Consuming Messages<\/h2>\n
Starting Kafka Console Producer<\/strong><\/p>\n
You can produce messages from standard input as follows:<\/p>\n
[npntraining ~]$ kafka-console-producer.sh --broker-list localhost:9092 --topic simple-producer-consumer\nMessage 01<\/code><\/pre>\n
Starting Kafka Console Consumer<\/strong><\/p>\n
[npntraining ~]$ kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic simple-producer-consumer\nMessage01<\/code><\/pre>\n
You can begin a consumer from the beginning of the log as follows:<\/p>\n
[npntraining ~]$ kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic simple-producer-consumer --from-beginning<\/code><\/pre>\n
Running JAR from Command Line<\/strong><\/p>\n
java -cp kafka-producer-0.0.1-SNAPSHOT-jar-with-dependencies.jar com.npntraining.SimpleProducer first-topic\njava -cp kafka-producer-0.0.1-SNAPSHOT-jar-with-dependencies.jar com.npntraining.SimpleConsumer my-first-topic<\/code><\/pre>\n
Producers<\/h2>\n
You can begin a consumer from the beginning of the log as follows:<\/p>\n
kafka-console-producer --broker-list localhost:9092 --topic test < messages.txt<\/code><\/pre>\n
You can produce Avro messages as follows:<\/p>\n
kafka-avro-console-producer --broker-list localhost:9092 --topic my.Topic --property value.schema='{"type":"record","name":"myrecord","fields":[{"name":"name","type":"string"}]}' --property schema.registry.url=http:\/\/localhost:8081<\/code><\/pre>\n
You can enter a few new values from the console as follows:<\/p>\n
{"name": "Naveen"}<\/code><\/pre>\n
Consumers<\/h2>\n
You can consume a single message as follows:<\/p>\n
kafka-console-consumer --bootstrap-server localhost:9092 --topic my-topic  --max-messages 1<\/code><\/pre>\n
You can consume 10 Avro messages from a topic named position-reports<\/code> as follows:<\/p>\n
kafka-avro-console-consumer --topic position-reports --new-consumer --bootstrap-server localhost:9092 --from-beginning --property schema.registry.url=localhost:8081 --max-messages 10<\/code><\/pre>\n
You can consume all existing Avro messages from a topic named position-reports<\/code> as follows:<\/p>\n
kafka-avro-console-consumer --topic position-reports --new-consumer --bootstrap-server localhost:9092 --from-beginning --property schema.registry.url=localhost:8081<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
Kafka Commands Starting Zookeeper & Kafka [npntraining ~]$ cd \\opt\\kafka\\zookeeper-3.5.6-bin\\bin [npntraining ~]$ zkserver.sh Starting Kafka [npntraining ~]$ cd \\opt\\kafka\\kafka_2.12-2.4.0\\bin\\ [npntraining ~]$ kafka-server-start.sh \\opt\\kafka\\kafka_2.12-2.4.0\\config\\server.properties Kafka Topic You can create a new…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-7931","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/www.npntraining.com\/blog\/wp-json\/wp\/v2\/posts\/7931","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.npntraining.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.npntraining.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.npntraining.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.npntraining.com\/blog\/wp-json\/wp\/v2\/comments?post=7931"}],"version-history":[{"count":2,"href":"https:\/\/www.npntraining.com\/blog\/wp-json\/wp\/v2\/posts\/7931\/revisions"}],"predecessor-version":[{"id":7933,"href":"https:\/\/www.npntraining.com\/blog\/wp-json\/wp\/v2\/posts\/7931\/revisions\/7933"}],"wp:attachment":[{"href":"https:\/\/www.npntraining.com\/blog\/wp-json\/wp\/v2\/media?parent=7931"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.npntraining.com\/blog\/wp-json\/wp\/v2\/categories?post=7931"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.npntraining.com\/blog\/wp-json\/wp\/v2\/tags?post=7931"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}