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.clients.consumer.ConsumerRebalanceListener;
   6 import org.apache.kafka.common.TopicPartition;
   7
   8 import java.time.Clock;
   9 import java.time.Duration;
  10 import java.time.Instant;
  11 import java.util.*;
  12
  13
  14 @RequiredArgsConstructor
  15 @Slf4j
  16 public class ApplicationRebalanceListener implements ConsumerRebalanceListener
  17 {
  18   private final ApplicationRecordHandler recordHandler;
  19   private final AdderResults adderResults;
  20   private final StateRepository stateRepository;
  21   private final String id;
  22
  23   private final Set<Integer> partitions = new HashSet<>();
  24
  25   @Override
  26   public void onPartitionsAssigned(Collection<TopicPartition> partitions)
  27   {
  28     partitions.forEach(tp ->
  29     {
  30       Integer partition = tp.partition();
  31       log.info("{} - adding partition: {}", id, partition);
  32       this.partitions.add(partition);
  33       StateDocument document =
  34           stateRepository
  35               .findById(Integer.toString(partition))
  36               .orElse(new StateDocument(partition));
  37       recordHandler.addPartition(partition, document.state);
  38       for (String user : document.state.keySet())
  39       {
  40         log.info(
  41             "{} - Restored state for partition={}|user={}: {}",
  42             id,
  43             partition,
  44             user,
  45             document.state.get(user));
  46       }
  47       adderResults.addPartition(partition, document.results);
  48     });
  49   }
  50
  51   @Override
  52   public void onPartitionsRevoked(Collection<TopicPartition> partitions)
  53   {
  54     partitions.forEach(tp ->
  55     {
  56       Integer partition = tp.partition();
  57       log.info("{} - removing partition: {}", id, partition);
  58       this.partitions.remove(partition);
  59       Map<String, AdderResult> state = recordHandler.removePartition(partition);
  60       for (String user : state.keySet())
  61       {
  62         log.info(
  63             "{} - Saved state for partition={}|user={}: {}",
  64             id,
  65             partition,
  66             user,
  67             state.get(user));
  68       }
  69       Map<String, List<AdderResult>> results = adderResults.removePartition(partition);
  70       stateRepository.save(new StateDocument(partition, state, results));
  71     });
  72   }
  73 }