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;
14 @RequiredArgsConstructor
16 public class ApplicationRebalanceListener implements PollIntervalAwareConsumerRebalanceListener
18 private final ApplicationRecordHandler recordHandler;
19 private final AdderResults adderResults;
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 final Set<Integer> partitions = new HashSet<>();
29 private Instant lastCommit = Instant.EPOCH;
30 private boolean commitsEnabled = true;
33 public void onPartitionsAssigned(Collection<TopicPartition> partitions)
35 partitions.forEach(tp ->
37 Integer partition = tp.partition();
38 this.partitions.add(partition);
39 StateDocument document =
41 .findById(Integer.toString(partition))
42 .orElse(new StateDocument(partition));
43 log.info("{} - adding partition: {}, offset={}", id, partition, document.offset);
44 if (document.offset >= 0)
46 // Only seek, if a stored offset was found
47 // Otherwise: Use initial offset, generated by Kafka
48 consumer.seek(tp, document.offset);
50 recordHandler.addPartition(partition, document.state);
51 adderResults.addPartition(partition, document.results);
56 public void onPartitionsRevoked(Collection<TopicPartition> partitions)
58 partitions.forEach(tp ->
60 Integer partition = tp.partition();
61 this.partitions.remove(partition);
62 Long offset = consumer.position(tp);
64 "{} - removing partition: {}, offset of next message {})",
70 Map<String, AdderResult> state = recordHandler.removePartition(partition);
71 Map<String, List<AdderResult>> results = adderResults.removePartition(partition);
72 stateRepository.save(new StateDocument(partition, state, results, offset));
76 log.info("Offset commits are disabled! Last commit: {}", lastCommit);
83 public void beforeNextPoll()
87 log.info("Offset commits are disabled! Last commit: {}", lastCommit);
91 if (lastCommit.plus(commitInterval).isBefore(clock.instant()))
93 log.debug("Storing data and offsets, last commit: {}", lastCommit);
94 partitions.forEach(partition -> stateRepository.save(
97 recordHandler.getState(partition).getState(),
98 adderResults.getState(partition),
99 consumer.position(new TopicPartition(topic, partition)))));
100 lastCommit = clock.instant();
105 public void enableCommits()
107 commitsEnabled = true;
111 public void disableCommits()
113 commitsEnabled = false;