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.common.serialization.StringSerializer;
   5
   6 import java.time.Clock;
   7 import java.time.Duration;
   8 import java.time.LocalTime;
   9 import java.util.List;
  10 import java.util.Properties;
  11
  12 import org.apache.kafka.clients.producer.KafkaProducer;
  13 import org.apache.kafka.clients.producer.ProducerRecord;
  14 import org.slf4j.Logger;
  15 import org.slf4j.LoggerFactory;
  16 import org.springframework.scheduling.annotation.Scheduled;
  17
  18 import javax.annotation.PreDestroy;
  19
  20 import static org.apache.kafka.clients.CommonClientConfigs.BOOTSTRAP_SERVERS_CONFIG;
  21 import static org.apache.kafka.clients.producer.ProducerConfig.*;
  22
  23
  24 public class OutboxProducer
  25 {
  26   final static Logger LOG = LoggerFactory.getLogger(OutboxProducer.class);
  27
  28
  29   private final OutboxRepository repository;
  30   private final KafkaProducer<String, String> producer;
  31   private final String topic;
  32   private final Watermarks watermarks;
  33   private final Clock clock;
  34   private final Duration cleanupInterval;
  35
  36   private long sequenceNumber = 0l;
  37   private LocalTime nextCleanup;
  38
  39   public OutboxProducer(
  40       ApplicationProperties properties,
  41       OutboxRepository repository,
  42       Clock clock)
  43   {
  44     this.repository = repository;
  45
  46     Properties props = new Properties();
  47     props.put(BOOTSTRAP_SERVERS_CONFIG, properties.bootstrapServers);
  48     props.put(KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
  49     props.put(VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
  50     props.put(ENABLE_IDEMPOTENCE_CONFIG, true);
  51
  52     this.producer = new KafkaProducer<>(props);
  53     this.topic = properties.topic;
  54
  55     this.watermarks = new Watermarks();
  56     this.clock = clock;
  57     this.cleanupInterval = properties.cleanupInterval;
  58     this.nextCleanup = LocalTime.now(clock).plus(cleanupInterval);
  59   }
  60
  61   @Scheduled(fixedDelayString = "${de.juplo.kafka.outbox.interval}")
  62   public void poll()
  63   {
  64     List<OutboxItem> items;
  65     do
  66     {
  67       items = repository.fetch(sequenceNumber);
  68       LOG.debug("Polled {} new items", items.size());
  69       for (OutboxItem item : items)
  70         send(item);
  71       if (nextCleanup.isBefore(LocalTime.now(clock)))
  72       {
  73         int deleted = repository.delete(watermarks.getLowest());
  74         nextCleanup = LocalTime.now(clock).plus(cleanupInterval);
  75         LOG.info(
  76             "Cleaned up {} entries from outbox, next clean-up: {}",
  77             deleted,
  78             nextCleanup);
  79       }
  80     }
  81     while (items.size() > 0);
  82   }
  83
  84   void send(OutboxItem item)
  85   {
  86     final ProducerRecord<String, String> record =
  87         new ProducerRecord<>(topic, item.getKey(), item.getValue());
  88
  89     sequenceNumber = item.getSequenceNumber();
  90     record.headers().add("SEQ#", Longs.toByteArray(sequenceNumber));
  91
  92     producer.send(record, (metadata, e) ->
  93     {
  94       if (metadata != null)
  95       {
  96         watermarks.set(metadata.partition(), item.getSequenceNumber());
  97         LOG.info(
  98             "{}/{}:{} - {}:{}={}",
  99             metadata.topic(),
 100             metadata.partition(),
 101             metadata.offset(),
 102             item.getSequenceNumber(),
 103             record.key(),
 104             record.value());
 105       }
 106       else
 107       {
 108         // HANDLE ERROR
 109         LOG.error(
 110             "{}/{} - {}:{}={} -> ",
 111             record.topic(),
 112             record.partition(),
 113             item.getSequenceNumber(),
 114             record.key(),
 115             record.value(),
 116             e);
 117       }
 118     });
 119   }
 120
 121
 122   @PreDestroy
 123   public void close()
 124   {
 125     producer.close(Duration.ofSeconds(5));
 126   }
 127 }