https://github.com/rbiedrawa/spring-kafka-non-blocking-retries
This repository demonstrates how to handle Kafka Consumer exceptions in a non-blocking manner using retry topics and DLQ (Dead Letter Queue).
https://github.com/rbiedrawa/spring-kafka-non-blocking-retries
apache-kafka dlq docker docker-compose gradle kafka kafka-consumer kowl retries spring-boot spring-kafka
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This repository demonstrates how to handle Kafka Consumer exceptions in a non-blocking manner using retry topics and DLQ (Dead Letter Queue).
- Host: GitHub
- URL: https://github.com/rbiedrawa/spring-kafka-non-blocking-retries
- Owner: rbiedrawa
- License: mit
- Created: 2021-06-15T15:49:52.000Z (over 4 years ago)
- Default Branch: master
- Last Pushed: 2022-01-31T02:04:23.000Z (over 3 years ago)
- Last Synced: 2025-03-21T23:43:26.543Z (7 months ago)
- Topics: apache-kafka, dlq, docker, docker-compose, gradle, kafka, kafka-consumer, kowl, retries, spring-boot, spring-kafka
- Language: Java
- Homepage:
- Size: 305 KB
- Stars: 1
- Watchers: 1
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: Readme.md
- License: LICENSE
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README
# Non-Blocking Retries in Kafka Consumers (demo)
This repository demonstrates how to handle Kafka Consumer exceptions in a non-blocking manner using retry topics and DLQ (Dead Letter Queue).
## Getting Started
### Prerequisites
* Java 11
* Docker
### Usage
* Start docker-compose.
```shell
docker-compose -f docker/docker-compose.yml up -d
```
* Start application.
```shell
./gradlew bootRun
```
* Run below command to produce random messages.
```shell
(cd docker && docker-compose exec broker bash -c "seq 2 | kafka-console-producer --request-required-acks 1 --broker-list localhost:29092 --topic my.topic.events && echo 'Produced 2 messages.'")
# >>>Produced 2 messages.
```
* Investigate application logs.
```shell
# 2021-06-15 17:20:12.200 [-listener-0-C-1] com.rbiedrawa.kafka.app.MyTopicListener : Received event 1 from topic my.topic.events
# 2021-06-15 17:20:12.710 [-listener-0-C-1] o.a.k.clients.consumer.KafkaConsumer : [Consumer clientId=consumer-my-topic-listener-1, groupId=my-topic-listener] Seeking to offset 3 for partition my.topic.events-0
# 2021-06-15 17:20:12.711 [etry-1000-0-C-1] o.a.k.clients.consumer.KafkaConsumer : [Consumer clientId=consumer-my-topic-listener-retry-1000-2, groupId=my-topic-listener-retry-1000] Seeking to offset 2 for partition my.topic.events-retry-1000-0
# 2021-06-15 17:20:12.711 [etry-1000-0-C-1] essageListenerContainer$ListenerConsumer : Seek to current after exception; nested exception is org.springframework.kafka.listener.ListenerExecutionFailedException: Listener failed; nested exception is org.springframework.kafka.listener.KafkaBackoffException: Partition 0 from topic my.topic.events-retry-1000 is not ready for consumption, backing off for approx. 490 millis.
# 2021-06-15 17:20:12.720 [-listener-0-C-1] com.rbiedrawa.kafka.app.MyTopicListener : Received event 2 from topic my.topic.events
# 2021-06-15 17:20:13.223 [etry-1000-0-C-1] com.rbiedrawa.kafka.app.MyTopicListener : Received event 1 from topic my.topic.events-retry-1000
# 2021-06-15 17:20:13.238 [etry-2000-0-C-1] o.a.k.clients.consumer.KafkaConsumer : [Consumer clientId=consumer-my-topic-listener-retry-2000-3, groupId=my-topic-listener-retry-2000] Seeking to offset 2 for partition my.topic.events-retry-2000-0
# 2021-06-15 17:20:13.238 [etry-2000-0-C-1] essageListenerContainer$ListenerConsumer : Seek to current after exception; nested exception is org.springframework.kafka.listener.ListenerExecutionFailedException: Listener failed; nested exception is org.springframework.kafka.listener.KafkaBackoffException: Partition 0 from topic my.topic.events-retry-2000 is not ready for consumption, backing off for approx. 1986 millis.
# 2021-06-15 17:20:13.245 [etry-1000-0-C-1] o.a.k.clients.consumer.KafkaConsumer : [Consumer clientId=consumer-my-topic-listener-retry-1000-2, groupId=my-topic-listener-retry-1000] Seeking to offset 3 for partition my.topic.events-retry-1000-0
# 2021-06-15 17:20:13.245 [etry-1000-0-C-1] essageListenerContainer$ListenerConsumer : Seek to current after exception; nested exception is org.springframework.kafka.listener.ListenerExecutionFailedException: Listener failed; nested exception is org.springframework.kafka.listener.KafkaBackoffException: Partition 0 from topic my.topic.events-retry-1000 is not ready for consumption, backing off for approx. 476 millis.
# 2021-06-15 17:20:13.867 [etry-1000-0-C-1] com.rbiedrawa.kafka.app.MyTopicListener : Received event 2 from topic my.topic.events-retry-1000
# 2021-06-15 17:20:15.298 [etry-2000-0-C-1] com.rbiedrawa.kafka.app.MyTopicListener : Received event 1 from topic my.topic.events-retry-2000
# 2021-06-15 17:20:15.810 [etry-2000-0-C-1] o.a.k.clients.consumer.KafkaConsumer : [Consumer clientId=consumer-my-topic-listener-retry-2000-3, groupId=my-topic-listener-retry-2000] Seeking to offset 3 for partition my.topic.events-retry-2000-0
# 2021-06-15 17:20:15.812 [tener-dlt-0-C-1] com.rbiedrawa.kafka.app.MyTopicListener : Event 1 handled by dlq topic: my.topic.events-dlt
# 2021-06-15 17:20:15.819 [etry-2000-0-C-1] o.a.k.clients.consumer.KafkaConsumer : [Consumer clientId=consumer-my-topic-listener-retry-2000-3, groupId=my-topic-listener-retry-2000] Seeking to offset 3 for partition my.topic.events-retry-2000-0
# 2021-06-15 17:20:15.819 [etry-2000-0-C-1] essageListenerContainer$ListenerConsumer : Seek to current after exception; nested exception is org.springframework.kafka.listener.ListenerExecutionFailedException: Listener failed; nested exception is org.springframework.kafka.listener.KafkaBackoffException: Partition 0 from topic my.topic.events-retry-2000 is not ready for consumption, backing off for approx. 49 millis.
# 2021-06-15 17:20:16.326 [etry-2000-0-C-1] com.rbiedrawa.kafka.app.MyTopicListener : Received event 2 from topic my.topic.events-retry-2000
# 2021-06-15 17:20:16.841 [tener-dlt-0-C-1] com.rbiedrawa.kafka.app.MyTopicListener : Event 2 handled by dlq topic: my.topic.events-dlt
```
* Open your web browser and go to [Kowl Web UI page](http://localhost:8080/).
* Check how many consumer groups are active.
* Check kafka topics
* Investigate kafka message headers in retry and dlq topics
## Important Endpoints
| Name | Endpoint |
| -------------:|:--------:|
| `Kowl Web UI` | http://localhost:8080 |
## References
* [Spring Kafka docs - Non-Blocking Retries](https://docs.spring.io/spring-kafka/reference/html/#retry-topic)
* [@RetryableTopic](https://docs.spring.io/spring-kafka/docs/current/api/org/springframework/kafka/annotation/RetryableTopic.html)
* [Uber - Building Reliable Reprocessing and Dead Letter Queues with Apache Kafka](https://eng.uber.com/reliable-reprocessing/)
## License
Distributed under the MIT License. See `LICENSE` for more information.