X-Git-Url: https://juplo.de/gitweb/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fde%2Fjuplo%2Fkafka%2FApplicationRebalanceListener.java;fp=src%2Fmain%2Fjava%2Fde%2Fjuplo%2Fkafka%2FApplicationRebalanceListener.java;h=2fccb4f28209ff6ef4c268bcb7c9eb42cd444f08;hb=4abc82d5d4cc80feabee91a10749b40f9bcfd879;hp=0000000000000000000000000000000000000000;hpb=2768e0f97c441ade5ce8ff371aa590fdc3cfd6c6;p=demos%2Fkafka%2Ftraining diff --git a/src/main/java/de/juplo/kafka/ApplicationRebalanceListener.java b/src/main/java/de/juplo/kafka/ApplicationRebalanceListener.java new file mode 100644 index 0000000..2fccb4f --- /dev/null +++ b/src/main/java/de/juplo/kafka/ApplicationRebalanceListener.java @@ -0,0 +1,83 @@ +package de.juplo.kafka; + +import lombok.RequiredArgsConstructor; +import lombok.extern.slf4j.Slf4j; +import org.apache.kafka.clients.consumer.Consumer; +import org.apache.kafka.common.TopicPartition; + +import java.time.Clock; +import java.time.Duration; +import java.time.Instant; +import java.util.Collection; +import java.util.Map; + + +@RequiredArgsConstructor +@Slf4j +public class ApplicationRebalanceListener implements PollIntervalAwareConsumerRebalanceListener +{ + private final ApplicationRecordHandler recordHandler; + private final StateRepository stateRepository; + private final String id; + private final String topic; + private final Clock clock; + private final Duration commitInterval; + private final Consumer consumer; + + private Instant lastCommit = Instant.EPOCH; + + @Override + public void onPartitionsAssigned(Collection partitions) + { + partitions.forEach(tp -> + { + Integer partition = tp.partition(); + Long offset = consumer.position(tp); + log.info("{} - adding partition: {}, offset={}", id, partition, offset); + StateDocument document = + stateRepository + .findById(Integer.toString(partition)) + .orElse(new StateDocument(partition)); + if (document.offset >= 0) + { + // Only seek, if a stored offset was found + // Otherwise: Use initial offset, generated by Kafka + consumer.seek(tp, document.offset); + } + recordHandler.addPartition(partition, document.state); + }); + } + + @Override + public void onPartitionsRevoked(Collection partitions) + { + partitions.forEach(tp -> + { + Integer partition = tp.partition(); + Long newOffset = consumer.position(tp); + log.info( + "{} - removing partition: {}, offset of next message {})", + id, + partition, + newOffset); + Map removed = recordHandler.removePartition(partition); + stateRepository.save(new StateDocument(partition, removed, consumer.position(tp))); + }); + } + + + @Override + public void beforeNextPoll() + { + if (lastCommit.plus(commitInterval).isBefore(clock.instant())) + { + log.debug("Storing data and offsets, last commit: {}", lastCommit); + recordHandler.getState().forEach((partiton, state) -> stateRepository.save( + new StateDocument( + partiton, + state, + consumer.position(new TopicPartition(topic, partiton))))); + lastCommit = clock.instant(); + } + } +}