juplo.de Git - demos/kafka/outbox/blob - delivery/src/main/java/de/juplo/kafka/outbox/delivery/OutboxProducer.java

   1 package de.juplo.kafka.outbox.delivery;
   2
   3 import com.google.common.primitives.Longs;
   4 import org.apache.kafka.clients.consumer.ConsumerRecords;
   5 import org.apache.kafka.clients.consumer.KafkaConsumer;
   6 import org.apache.kafka.clients.consumer.OffsetAndMetadata;
   7 import org.apache.kafka.common.PartitionInfo;
   8 import org.apache.kafka.common.TopicPartition;
   9 import org.apache.kafka.common.serialization.StringDeserializer;
  10 import org.apache.kafka.common.serialization.StringSerializer;
  11
  12 import java.time.Clock;
  13 import java.time.Duration;
  14 import java.time.LocalTime;
  15 import java.util.*;
  16
  17 import org.apache.kafka.clients.producer.KafkaProducer;
  18 import org.apache.kafka.clients.producer.ProducerRecord;
  19 import org.slf4j.Logger;
  20 import org.slf4j.LoggerFactory;
  21 import org.springframework.scheduling.annotation.Scheduled;
  22
  23 import javax.annotation.PreDestroy;
  24
  25 import static org.apache.kafka.clients.CommonClientConfigs.BOOTSTRAP_SERVERS_CONFIG;
  26 import static org.apache.kafka.clients.consumer.ConsumerConfig.*;
  27 import static org.apache.kafka.clients.producer.ProducerConfig.*;
  28
  29
  30 public class OutboxProducer
  31 {
  32   final static Logger LOG = LoggerFactory.getLogger(OutboxProducer.class);
  33
  34   public final static String HEADER = "#";
  35
  36   private final OutboxRepository repository;
  37   private final KafkaProducer<String, String> producer;
  38   private final String topic;
  39   private final Set<Long> send = new HashSet<>();
  40   private final Clock clock;
  41   private final Duration cleanupInterval;
  42
  43   private long sequenceNumber = 0l;
  44   private LocalTime nextCleanup;
  45
  46   public OutboxProducer(
  47       ApplicationProperties properties,
  48       OutboxRepository repository,
  49       Clock clock)
  50   {
  51     this.repository = repository;
  52
  53     Properties props = new Properties();
  54     props.put(BOOTSTRAP_SERVERS_CONFIG, properties.bootstrapServers);
  55     props.put(KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
  56     props.put(VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
  57     props.put(ENABLE_IDEMPOTENCE_CONFIG, true);
  58
  59     this.producer = new KafkaProducer<>(props);
  60     this.topic = properties.topic;
  61
  62     props = new Properties();
  63     props.put(BOOTSTRAP_SERVERS_CONFIG, properties.bootstrapServers);
  64     props.put(GROUP_ID_CONFIG, "outbox");
  65     props.put(KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
  66     props.put(VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
  67
  68     List<PartitionInfo> partitions = consumer.listTopics().get(this.topic);
  69     Set<TopicPartition> assignment = new HashSet<>();
  70     for (PartitionInfo info : partitions)
  71     {
  72       LOG.debug("Found {}/{} (ISR: {})", info.topic(), info.partition(), info.inSyncReplicas());
  73       assignment.add(new TopicPartition(info.topic(), info.partition()));
  74     }
  75
  76     LOG.info("Using topic {} with {} partitions", topic, partitions);
  77
  78     KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
  79     consumer.assign(assignment);
  80
  81     long[] currentOffsets = new long[partitions.size()];
  82     for (Map.Entry<TopicPartition, OffsetAndMetadata> entry : consumer.committed(assignment).entrySet())
  83     {
  84       LOG.info("Found current offset {} for partition {}", entry.getValue(), entry.getKey());
  85       currentOffsets[entry.getKey().partition()] = entry.getValue().offset() - 1l;
  86     }
  87     LOG.info("Current offsets: {}", currentOffsets);
  88
  89     long[] endOffsets = new long[partitions.size()];
  90     for (Map.Entry<TopicPartition, Long> entry : consumer.endOffsets(assignment).entrySet())
  91     {
  92       LOG.info("Found next offset {} for partition {}", entry.getValue(), entry.getKey());
  93       endOffsets[entry.getKey().partition()] = entry.getValue() - 1l;
  94     }
  95     LOG.info("End-offsets: {}", endOffsets);
  96
  97     int deleted = 0;
  98     while(!Arrays.equals(currentOffsets, endOffsets))
  99     {
 100       ConsumerRecords<String, String> records = consumer.poll(Duration.ofSeconds(1));
 101       LOG.debug("Fetched {} records", records.count());
 102       records.forEach(record ->
 103       {
 104         long recordSequenceNumber = Longs.fromByteArray(record.headers().lastHeader(HEADER).value());
 105         LOG.debug(
 106             "Found message #{} on offset {} of partition {}",
 107             recordSequenceNumber,
 108             record.offset(),
 109             record.partition());
 110         send.add(recordSequenceNumber);
 111         currentOffsets[record.partition()] = record.offset();
 112       });
 113       deleted += cleanUp();
 114       LOG.debug("Current offsets: {}", currentOffsets);
 115     }
 116
 117     LOG.info("Cleaned up {} already send entries from outbox table", deleted);
 118
 119     consumer.close();
 120
 121     this.clock = clock;
 122     this.cleanupInterval = properties.cleanupInterval;
 123     this.nextCleanup = LocalTime.now(clock).plus(this.cleanupInterval);
 124   }
 125
 126   @Scheduled(fixedDelayString = "${de.juplo.kafka.outbox.interval}")
 127   public void poll()
 128   {
 129     List<OutboxItem> items;
 130     do
 131     {
 132       items = repository.fetch(sequenceNumber);
 133       LOG.debug("Polled {} new items", items.size());
 134       for (OutboxItem item : items)
 135         send(item);
 136       if (nextCleanup.isBefore(LocalTime.now(clock)))
 137       {
 138         cleanUp();
 139         nextCleanup = LocalTime.now(clock).plus(cleanupInterval);
 140         LOG.debug("Next clean-up: {}", nextCleanup);
 141       }
 142     }
 143     while (items.size() > 0);
 144   }
 145
 146   int cleanUp()
 147   {
 148     int deleted = repository.delete(send);
 149     LOG.debug("Cleaned up {}/{} entries from outbox, next clean-up: {}", deleted, send.size());
 150     send.clear();
 151     return deleted;
 152   }
 153
 154   void send(OutboxItem item)
 155   {
 156     final ProducerRecord<String, String> record =
 157         new ProducerRecord<>(topic, item.getKey(), item.getValue());
 158
 159     sequenceNumber = item.getSequenceNumber();
 160     record.headers().add(HEADER, Longs.toByteArray(sequenceNumber));
 161
 162     producer.send(record, (metadata, e) ->
 163     {
 164       if (metadata != null)
 165       {
 166         send.add(item.getSequenceNumber());
 167         LOG.info(
 168             "{}/{}:{} - {}:{}={}",
 169             metadata.topic(),
 170             metadata.partition(),
 171             metadata.offset(),
 172             item.getSequenceNumber(),
 173             record.key(),
 174             record.value());
 175       }
 176       else
 177       {
 178         // HANDLE ERROR
 179         LOG.error(
 180             "{}/{} - {}:{}={} -> ",
 181             record.topic(),
 182             record.partition(),
 183             item.getSequenceNumber(),
 184             record.key(),
 185             record.value(),
 186             e);
 187       }
 188     });
 189   }
 190
 191
 192   @PreDestroy
 193   public void close()
 194   {
 195     producer.close(Duration.ofSeconds(5));
 196   }
 197 }