private void read(final KafkaStream<String, String> stream) {
while (stream.iterator().hasNext()) {
final int phase = phaser.register();
final MessageAndMetadata<String, String> msg = stream.iterator().next();
final long offset = msg.offset();
final long partition = msg.partition();
unacknowledgedOffsets.add(offset);
lastCommittedOffset.compareAndSet(0, offset);
currentPartition.compareAndSet(-1, partition);
final String jsonString = msg.message();
handler.handle(
configuration.getVertxAddress(),
jsonString,
() -> {
unacknowledgedOffsets.remove(offset);
phaser.arriveAndDeregister();
});
if (unacknowledgedOffsets.size() >= configuration.getMaxUnacknowledged()
|| partititionChanged(partition)
|| tooManyUncommittedOffsets(offset)) {
LOG.info(
"Got {} unacknowledged messages, waiting for ACKs in order to commit",
unacknowledgedOffsets.size());
if (!waitForAcks(phase)) {
return;
}
LOG.info("Continuing message processing");
commitOffsetsIfAllAcknowledged(offset);
}
}
}
public static VertxKafkaConsumer create(
final KafkaConfiguration configuration, final KafkaHandler handler) {
final Properties properties =
createProperties(
configuration.getZookeeper(),
configuration.getGroupId(),
configuration.getZookeeperTimeout());
final ConsumerConfig config = new ConsumerConfig(properties);
final ConsumerConnector connector = Consumer.createJavaConsumerConnector(config);
return new VertxKafkaConsumer(connector, configuration, handler);
}
public void start() {
final String kafkaTopic = configuration.getKafkaTopic();
final Map<String, List<KafkaStream<String, String>>> messageStreams =
connector.createMessageStreams(
ImmutableMap.of(kafkaTopic, 1), new StringDecoder(null), new StringDecoder(null));
final List<KafkaStream<String, String>> topicStreams = messageStreams.get(kafkaTopic);
final KafkaStream<String, String> topicStream = Iterables.getOnlyElement(topicStreams);
messageProcessorExececutor.submit(() -> read(topicStream));
}
private boolean waitForAcks(int phase) {
try {
phaser.awaitAdvanceInterruptibly(phase, 10, TimeUnit.MINUTES);
return true;
} catch (InterruptedException e) {
LOG.error("Interrupted while waiting for ACKs", e);
return false;
} catch (TimeoutException e) {
LOG.error(
"Waited for {} ACKs for longer than {} minutes, not making any progress ({}/{})",
new Object[] {
Integer.valueOf(unacknowledgedOffsets.size()),
Long.valueOf(configuration.getAckTimeoutMinutes()),
Integer.valueOf(phase), Integer.valueOf(phaser.getPhase())
});
return waitForAcks(phase);
}
}
private boolean tooManyUncommittedOffsets(final long offset) {
return lastCommittedOffset.get() + configuration.getMaxUncommitedOffsets() <= offset;
}