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(AUTO_OFFSET_RESET_CONFIG, "earliest");
  66     props.put(KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
  67     props.put(VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
  68
  69     List<PartitionInfo> partitions = consumer.listTopics().get(this.topic);
  70     Set<TopicPartition> assignment = new HashSet<>();
  71     for (PartitionInfo info : partitions)
  72     {
  73       LOG.debug("Found {}/{} (ISR: {})", info.topic(), info.partition(), info.inSyncReplicas());
  74       assignment.add(new TopicPartition(info.topic(), info.partition()));
  75     }
  76
  77     LOG.info("Using topic {} with {} partitions", topic, partitions);
  78
  79     KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
  80     consumer.assign(assignment);
  81
  82     long[] currentOffsets = new long[partitions.size()];
  83     for (Map.Entry<TopicPartition, OffsetAndMetadata> entry : consumer.committed(assignment).entrySet())
  84     {
  85       if (entry.getValue() == null)
  86       {
  87         LOG.debug("Found no offset for partition {}", entry.getKey());
  88         currentOffsets[entry.getKey().partition()] = -1l;
  89       }
  90       else
  91       {
  92         LOG.debug("Found current offset {} for partition {}", entry.getValue(), entry.getKey());
  93         currentOffsets[entry.getKey().partition()] = entry.getValue().offset() - 1l;
  94       }
  95     }
  96     LOG.info("Current offsets: {}", currentOffsets);
  97
  98     long[] endOffsets = new long[partitions.size()];
  99     for (Map.Entry<TopicPartition, Long> entry : consumer.endOffsets(assignment).entrySet())
 100     {
 101       LOG.debug("Found next offset {} for partition {}", entry.getValue(), entry.getKey());
 102       endOffsets[entry.getKey().partition()] = entry.getValue() - 1l;
 103     }
 104     LOG.info("End-offsets: {}", endOffsets);
 105
 106     int deleted = 0;
 107     while(!Arrays.equals(currentOffsets, endOffsets))
 108     {
 109       ConsumerRecords<String, String> records = consumer.poll(Duration.ofSeconds(1));
 110       LOG.debug("Fetched {} records", records.count());
 111       records.forEach(record ->
 112       {
 113         long recordSequenceNumber = Longs.fromByteArray(record.headers().lastHeader(HEADER).value());
 114         LOG.debug(
 115             "Found message #{} on offset {} of partition {}",
 116             recordSequenceNumber,
 117             record.offset(),
 118             record.partition());
 119         send.add(recordSequenceNumber);
 120         currentOffsets[record.partition()] = record.offset();
 121       });
 122       deleted += cleanUp();
 123       LOG.debug("Current offsets: {}", currentOffsets);
 124     }
 125
 126     LOG.info("Cleaned up {} already send entries from outbox table", deleted);
 127
 128     consumer.close();
 129
 130     this.clock = clock;
 131     this.cleanupInterval = properties.cleanupInterval;
 132     this.nextCleanup = LocalTime.now(clock).plus(this.cleanupInterval);
 133   }
 134
 135   @Scheduled(fixedDelayString = "${de.juplo.kafka.outbox.interval}")
 136   public void poll()
 137   {
 138     List<OutboxItem> items;
 139     do
 140     {
 141       items = repository.fetch(sequenceNumber);
 142       LOG.debug("Polled {} new items", items.size());
 143       for (OutboxItem item : items)
 144         send(item);
 145       if (nextCleanup.isBefore(LocalTime.now(clock)))
 146       {
 147         cleanUp();
 148         nextCleanup = LocalTime.now(clock).plus(cleanupInterval);
 149         LOG.debug("Next clean-up: {}", nextCleanup);
 150       }
 151     }
 152     while (items.size() > 0);
 153   }
 154
 155   int cleanUp()
 156   {
 157     int deleted = repository.delete(send);
 158     LOG.debug("Cleaned up {}/{} entries from outbox", deleted, send.size());
 159     send.clear();
 160     return deleted;
 161   }
 162
 163   void send(OutboxItem item)
 164   {
 165     final ProducerRecord<String, String> record =
 166         new ProducerRecord<>(topic, item.getKey(), item.getValue());
 167
 168     sequenceNumber = item.getSequenceNumber();
 169     record.headers().add(HEADER, Longs.toByteArray(sequenceNumber));
 170
 171     producer.send(record, (metadata, e) ->
 172     {
 173       if (metadata != null)
 174       {
 175         send.add(item.getSequenceNumber());
 176         LOG.info(
 177             "{}/{}:{} - {}:{}={}",
 178             metadata.topic(),
 179             metadata.partition(),
 180             metadata.offset(),
 181             item.getSequenceNumber(),
 182             record.key(),
 183             record.value());
 184       }
 185       else
 186       {
 187         // HANDLE ERROR
 188         LOG.error(
 189             "{}/{} - {}:{}={} -> ",
 190             record.topic(),
 191             record.partition(),
 192             item.getSequenceNumber(),
 193             record.key(),
 194             record.value(),
 195             e);
 196       }
 197     });
 198   }
 199
 200
 201   @PreDestroy
 202   public void close()
 203   {
 204     producer.close(Duration.ofSeconds(5));
 205   }
 206 }