juplo.de Git - demos/kafka/training/blob - src/main/java/de/juplo/kafka/ApplicationRebalanceListener.java

   1 package de.juplo.kafka;
   2
   3 import lombok.RequiredArgsConstructor;
   4 import lombok.extern.slf4j.Slf4j;
   5 import org.apache.kafka.common.TopicPartition;
   6
   7 import java.time.Clock;
   8 import java.time.Duration;
   9 import java.time.Instant;
  10 import java.util.Collection;
  11 import java.util.Map;
  12
  13
  14 @RequiredArgsConstructor
  15 @Slf4j
  16 public class ApplicationRebalanceListener implements PollIntervalAwareConsumerRebalanceListener
  17 {
  18   private final ApplicationRecordHandler recordHandler;
  19   private final StateRepository stateRepository;
  20   private final String id;
  21   private final Clock clock;
  22   private final Duration commitInterval;
  23
  24   private Instant lastCommit = Instant.EPOCH;
  25
  26   @Override
  27   public void onPartitionsAssigned(Collection<TopicPartition> partitions)
  28   {
  29     partitions.forEach(tp ->
  30     {
  31       Integer partition = tp.partition();
  32       log.info("{} - adding partition: {}", id, partition);
  33       StateDocument document =
  34           stateRepository
  35               .findById(Integer.toString(partition))
  36               .orElse(new StateDocument(partition));
  37       recordHandler.addPartition(partition, document.state);
  38     });
  39   }
  40
  41   @Override
  42   public void onPartitionsRevoked(Collection<TopicPartition> partitions)
  43   {
  44     partitions.forEach(tp ->
  45     {
  46       Integer partition = tp.partition();
  47       log.info("{} - removing partition: {}", id, partition);
  48       Map<String, Long> removed = recordHandler.removePartition(partition);
  49       for (String key : removed.keySet())
  50       {
  51         log.info(
  52             "{} - Seen {} messages for partition={}|key={}",
  53             id,
  54             removed.get(key),
  55             partition,
  56             key);
  57       }
  58       stateRepository.save(new StateDocument(partition, removed));
  59     });
  60   }
  61
  62
  63   @Override
  64   public void beforeNextPoll()
  65   {
  66     if (lastCommit.plus(commitInterval).isBefore(clock.instant()))
  67     {
  68       log.debug("Storing data, last commit: {}", lastCommit);
  69       recordHandler.getState().forEach((partiton, adder) -> stateRepository.save(
  70           new StateDocument(
  71               partiton,
  72               adder.getState())));
  73       lastCommit = clock.instant();
  74     }
  75   }
  76 }