1 package de.juplo.kafka;
3 import lombok.RequiredArgsConstructor;
4 import lombok.extern.slf4j.Slf4j;
5 import org.apache.kafka.clients.consumer.Consumer;
6 import org.apache.kafka.common.TopicPartition;
8 import java.time.Clock;
9 import java.time.Duration;
10 import java.time.Instant;
11 import java.util.Collection;
15 @RequiredArgsConstructor
17 public class ApplicationRebalanceListener implements PollIntervalAwareConsumerRebalanceListener
19 private final ApplicationRecordHandler recordHandler;
20 private final StateRepository stateRepository;
21 private final String id;
22 private final String topic;
23 private final Clock clock;
24 private final Duration commitInterval;
25 private final Consumer<String, String> consumer;
27 private Instant lastCommit = Instant.EPOCH;
28 private boolean commitsEnabled = true;
31 public void onPartitionsAssigned(Collection<TopicPartition> partitions)
33 partitions.forEach(tp ->
35 Integer partition = tp.partition();
36 StateDocument document =
38 .findById(Integer.toString(partition))
39 .orElse(new StateDocument(partition));
40 log.info("{} - adding partition: {}, offset={}", id, partition, document.offset);
41 if (document.offset >= 0)
43 // Only seek, if a stored offset was found
44 // Otherwise: Use initial offset, generated by Kafka
45 consumer.seek(tp, document.offset);
47 recordHandler.addPartition(partition, document.state);
52 public void onPartitionsRevoked(Collection<TopicPartition> partitions)
54 partitions.forEach(tp ->
56 Integer partition = tp.partition();
57 Long offset = consumer.position(tp);
59 "{} - removing partition: {}, offset of next message {})",
65 Map<String, Long> removed = recordHandler.removePartition(partition);
66 stateRepository.save(new StateDocument(partition, removed, offset));
70 log.info("Offset commits are disabled! Last commit: {}", lastCommit);
77 public void beforeNextPoll()
81 log.info("Offset commits are disabled! Last commit: {}", lastCommit);
85 if (lastCommit.plus(commitInterval).isBefore(clock.instant()))
87 log.debug("Storing data and offsets, last commit: {}", lastCommit);
88 recordHandler.getState().forEach((partiton, adder) -> stateRepository.save(
92 consumer.position(new TopicPartition(topic, partiton)))));
93 lastCommit = clock.instant();
98 public void enableCommits()
100 commitsEnabled = true;
104 public void disableCommits()
106 commitsEnabled = false;