--- /dev/null
-import org.apache.kafka.clients.consumer.Consumer;
+ package de.juplo.kafka;
+
+ import lombok.RequiredArgsConstructor;
+ import lombok.extern.slf4j.Slf4j;
- private final String topic;
+ import org.apache.kafka.common.TopicPartition;
+
+ import java.time.Clock;
+ import java.time.Duration;
+ import java.time.Instant;
+ import java.util.Collection;
+ import java.util.Map;
+
+
+ @RequiredArgsConstructor
+ @Slf4j
+ public class ApplicationRebalanceListener implements PollIntervalAwareConsumerRebalanceListener
+ {
+ private final ApplicationRecordHandler recordHandler;
+ private final StateRepository stateRepository;
+ private final String id;
- private final Consumer<String, Long> consumer;
+ private final Clock clock;
+ private final Duration commitInterval;
- private boolean commitsEnabled = true;
+
+ private Instant lastCommit = Instant.EPOCH;
- log.info("{} - adding partition: {}, offset={}", id, partition, document.offset);
- if (document.offset >= 0)
- {
- // Only seek, if a stored offset was found
- // Otherwise: Use initial offset, generated by Kafka
- consumer.seek(tp, document.offset);
- }
+
+ @Override
+ public void onPartitionsAssigned(Collection<TopicPartition> partitions)
+ {
+ partitions.forEach(tp ->
+ {
+ Integer partition = tp.partition();
++ log.info("{} - adding partition: {}", id, partition);
+ StateDocument document =
+ stateRepository
+ .findById(Integer.toString(partition))
+ .orElse(new StateDocument(partition));
- Long offset = consumer.position(tp);
- log.info(
- "{} - removing partition: {}, offset of next message {})",
- id,
- partition,
- offset);
- if (commitsEnabled)
- {
- Map<String, Long> removed = recordHandler.removePartition(partition);
- stateRepository.save(new StateDocument(partition, removed, offset));
- }
- else
+ recordHandler.addPartition(partition, document.state);
+ });
+ }
+
+ @Override
+ public void onPartitionsRevoked(Collection<TopicPartition> partitions)
+ {
+ partitions.forEach(tp ->
+ {
+ Integer partition = tp.partition();
- log.info("Offset commits are disabled! Last commit: {}", lastCommit);
++ log.info("{} - removing partition: {}", id, partition);
++ Map<String, Long> removed = recordHandler.removePartition(partition);
++ for (String key : removed.keySet())
+ {
- if (!commitsEnabled)
- {
- log.info("Offset commits are disabled! Last commit: {}", lastCommit);
- return;
- }
-
++ log.info(
++ "{} - Seen {} messages for partition={}|key={}",
++ id,
++ removed.get(key),
++ partition,
++ key);
+ }
++ stateRepository.save(new StateDocument(partition, removed));
+ });
+ }
+
+
+ @Override
+ public void beforeNextPoll()
+ {
- log.debug("Storing data and offsets, last commit: {}", lastCommit);
- recordHandler.getState().forEach((partiton, state) -> stateRepository.save(
+ if (lastCommit.plus(commitInterval).isBefore(clock.instant()))
+ {
- state,
- consumer.position(new TopicPartition(topic, partiton)))));
++ log.debug("Storing data, last commit: {}", lastCommit);
++ recordHandler.getState().forEach((partiton, statistics) -> stateRepository.save(
+ new StateDocument(
+ partiton,
-
- @Override
- public void enableCommits()
- {
- commitsEnabled = true;
- }
-
- @Override
- public void disableCommits()
- {
- commitsEnabled = false;
- }
++ statistics)));
+ lastCommit = clock.instant();
+ }
+ }
+ }
--- /dev/null
- StateRepository stateRepository;
- @Autowired
+ package de.juplo.kafka;
+
+ import lombok.extern.slf4j.Slf4j;
+ import org.apache.kafka.clients.consumer.ConsumerRecord;
+ import org.apache.kafka.clients.consumer.KafkaConsumer;
+ import org.apache.kafka.clients.producer.KafkaProducer;
+ import org.apache.kafka.clients.producer.ProducerRecord;
+ import org.apache.kafka.common.TopicPartition;
+ import org.apache.kafka.common.errors.RecordDeserializationException;
+ import org.apache.kafka.common.serialization.*;
+ import org.apache.kafka.common.utils.Bytes;
+ import org.junit.jupiter.api.*;
+ import org.springframework.beans.factory.annotation.Autowired;
+ import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+ import org.springframework.boot.test.autoconfigure.data.mongo.AutoConfigureDataMongo;
+ import org.springframework.boot.test.context.ConfigDataApplicationContextInitializer;
+ import org.springframework.boot.test.context.TestConfiguration;
+ import org.springframework.context.annotation.Import;
+ import org.springframework.kafka.test.context.EmbeddedKafka;
+ import org.springframework.test.context.TestPropertySource;
+ import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
+
+ import java.time.Duration;
+ import java.util.*;
+ import java.util.concurrent.ExecutorService;
+ import java.util.function.BiConsumer;
+ import java.util.function.Consumer;
+ import java.util.stream.Collectors;
+ import java.util.stream.IntStream;
+
+ import static de.juplo.kafka.GenericApplicationTests.PARTITIONS;
+ import static de.juplo.kafka.GenericApplicationTests.TOPIC;
+ import static org.assertj.core.api.Assertions.*;
+ import static org.awaitility.Awaitility.*;
+
+
+ @SpringJUnitConfig(initializers = ConfigDataApplicationContextInitializer.class)
+ @TestPropertySource(
+ properties = {
+ "consumer.bootstrap-server=${spring.embedded.kafka.brokers}",
+ "consumer.topic=" + TOPIC,
+ "consumer.commit-interval=1s",
+ "spring.mongodb.embedded.version=4.4.13" })
+ @EmbeddedKafka(topics = TOPIC, partitions = PARTITIONS)
+ @EnableAutoConfiguration
+ @AutoConfigureDataMongo
+ @Slf4j
+ abstract class GenericApplicationTests<K, V>
+ {
+ public static final String TOPIC = "FOO";
+ public static final int PARTITIONS = 10;
+
+
+ @Autowired
+ KafkaConsumer<K, V> kafkaConsumer;
+ @Autowired
+ Consumer<ConsumerRecord<K, V>> consumer;
+ @Autowired
+ ApplicationProperties properties;
+ @Autowired
+ ExecutorService executor;
+ @Autowired
- Integer partition = tp.partition();
- StateDocument document =
- stateRepository
- .findById(partition.toString())
- .orElse(new StateDocument(partition));
- document.offset = offset;
- stateRepository.save(document);
+ PollIntervalAwareConsumerRebalanceListener rebalanceListener;
+ @Autowired
+ RecordHandler<K, V> recordHandler;
+
+ KafkaProducer<Bytes, Bytes> testRecordProducer;
+ KafkaConsumer<Bytes, Bytes> offsetConsumer;
+ EndlessConsumer<K, V> endlessConsumer;
+ Map<TopicPartition, Long> oldOffsets;
+ Map<TopicPartition, Long> newOffsets;
+ Set<ConsumerRecord<K, V>> receivedRecords;
+
+
+ final RecordGenerator recordGenerator;
+ final Consumer<ProducerRecord<Bytes, Bytes>> messageSender;
+
+ public GenericApplicationTests(RecordGenerator recordGenerator)
+ {
+ this.recordGenerator = recordGenerator;
+ this.messageSender = (record) -> sendMessage(record);
+ }
+
+
+ /** Tests methods */
+
+ @Test
+ void commitsCurrentOffsetsOnSuccess()
+ {
+ int numberOfGeneratedMessages =
+ recordGenerator.generate(false, false, messageSender);
+
+ await(numberOfGeneratedMessages + " records received")
+ .atMost(Duration.ofSeconds(30))
+ .pollInterval(Duration.ofSeconds(1))
+ .until(() -> receivedRecords.size() >= numberOfGeneratedMessages);
+
+ await("Offsets committed")
+ .atMost(Duration.ofSeconds(10))
+ .pollInterval(Duration.ofSeconds(1))
+ .untilAsserted(() ->
+ {
+ checkSeenOffsetsForProgress();
+ compareToCommitedOffsets(newOffsets);
+ });
+
+ assertThatExceptionOfType(IllegalStateException.class)
+ .isThrownBy(() -> endlessConsumer.exitStatus())
+ .describedAs("Consumer should still be running");
+
+ recordGenerator.assertBusinessLogic();
+ }
+
+ @Test
+ @SkipWhenErrorCannotBeGenerated(poisonPill = true)
+ void commitsOffsetOfErrorForReprocessingOnDeserializationError()
+ {
+ int numberOfGeneratedMessages =
+ recordGenerator.generate(true, false, messageSender);
+
+ await("Consumer failed")
+ .atMost(Duration.ofSeconds(30))
+ .pollInterval(Duration.ofSeconds(1))
+ .until(() -> !endlessConsumer.running());
+
+ checkSeenOffsetsForProgress();
+ compareToCommitedOffsets(newOffsets);
+
+ endlessConsumer.start();
+ await("Consumer failed")
+ .atMost(Duration.ofSeconds(30))
+ .pollInterval(Duration.ofSeconds(1))
+ .until(() -> !endlessConsumer.running());
+
+ checkSeenOffsetsForProgress();
+ compareToCommitedOffsets(newOffsets);
+ assertThat(receivedRecords.size())
+ .describedAs("Received not all sent events")
+ .isLessThan(numberOfGeneratedMessages);
+
+ assertThatNoException()
+ .describedAs("Consumer should not be running")
+ .isThrownBy(() -> endlessConsumer.exitStatus());
+ assertThat(endlessConsumer.exitStatus())
+ .describedAs("Consumer should have exited abnormally")
+ .containsInstanceOf(RecordDeserializationException.class);
+
+ recordGenerator.assertBusinessLogic();
+ }
+
+ @Test
+ @SkipWhenErrorCannotBeGenerated(logicError = true)
+ void doesNotCommitOffsetsOnLogicError()
+ {
+ int numberOfGeneratedMessages =
+ recordGenerator.generate(false, true, messageSender);
+
+ await("Consumer failed")
+ .atMost(Duration.ofSeconds(30))
+ .pollInterval(Duration.ofSeconds(1))
+ .until(() -> !endlessConsumer.running());
+
+ checkSeenOffsetsForProgress();
+ compareToCommitedOffsets(oldOffsets);
+
+ endlessConsumer.start();
+ await("Consumer failed")
+ .atMost(Duration.ofSeconds(30))
+ .pollInterval(Duration.ofSeconds(1))
+ .until(() -> !endlessConsumer.running());
+
+ checkSeenOffsetsForProgress();
+ compareToCommitedOffsets(oldOffsets);
+ assertThat(receivedRecords.size())
+ .describedAs("Received not all sent events")
+ .isLessThan(numberOfGeneratedMessages);
+
+ assertThatNoException()
+ .describedAs("Consumer should not be running")
+ .isThrownBy(() -> endlessConsumer.exitStatus());
+ assertThat(endlessConsumer.exitStatus())
+ .describedAs("Consumer should have exited abnormally")
+ .containsInstanceOf(RuntimeException.class);
+
+ recordGenerator.assertBusinessLogic();
+ }
+
+
+ /** Helper methods for the verification of expectations */
+
+ void compareToCommitedOffsets(Map<TopicPartition, Long> offsetsToCheck)
+ {
+ doForCurrentOffsets((tp, offset) ->
+ {
+ Long expected = offsetsToCheck.get(tp) + 1;
+ log.debug("Checking, if the offset for {} is {}", tp, expected);
+ assertThat(offset)
+ .describedAs("Committed offset corresponds to the offset of the consumer")
+ .isEqualTo(expected);
+ });
+ }
+
+ void checkSeenOffsetsForProgress()
+ {
+ // Be sure, that some messages were consumed...!
+ Set<TopicPartition> withProgress = new HashSet<>();
+ partitions().forEach(tp ->
+ {
+ Long oldOffset = oldOffsets.get(tp) + 1;
+ Long newOffset = newOffsets.get(tp) + 1;
+ if (!oldOffset.equals(newOffset))
+ {
+ log.debug("Progress for {}: {} -> {}", tp, oldOffset, newOffset);
+ withProgress.add(tp);
+ }
+ });
+ assertThat(withProgress)
+ .describedAs("Some offsets must have changed, compared to the old offset-positions")
+ .isNotEmpty();
+ }
+
+
+ /** Helper methods for setting up and running the tests */
+
+ void seekToEnd()
+ {
+ offsetConsumer.assign(partitions());
++ offsetConsumer.seekToEnd(partitions());
+ partitions().forEach(tp ->
+ {
++ // seekToEnd() works lazily: it only takes effect on poll()/position()
+ Long offset = offsetConsumer.position(tp);
+ log.info("New position for {}: {}", tp, offset);
- partitions().forEach(tp ->
- {
- String partition = Integer.toString(tp.partition());
- Optional<Long> offset = stateRepository.findById(partition).map(document -> document.offset);
- consumer.accept(tp, offset.orElse(0l));
- });
+ });
++ // The new positions must be commited!
++ offsetConsumer.commitSync();
+ offsetConsumer.unsubscribe();
+ }
+
+ void doForCurrentOffsets(BiConsumer<TopicPartition, Long> consumer)
+ {
++ offsetConsumer.assign(partitions());
++ partitions().forEach(tp -> consumer.accept(tp, offsetConsumer.position(tp)));
++ offsetConsumer.unsubscribe();
+ }
+
+ List<TopicPartition> partitions()
+ {
+ return
+ IntStream
+ .range(0, PARTITIONS)
+ .mapToObj(partition -> new TopicPartition(TOPIC, partition))
+ .collect(Collectors.toList());
+ }
+
+
+ public interface RecordGenerator
+ {
+ int generate(
+ boolean poisonPills,
+ boolean logicErrors,
+ Consumer<ProducerRecord<Bytes, Bytes>> messageSender);
+
+ default boolean canGeneratePoisonPill()
+ {
+ return true;
+ }
+
+ default boolean canGenerateLogicError()
+ {
+ return true;
+ }
+
+ default void assertBusinessLogic()
+ {
+ log.debug("No business-logic to assert");
+ }
+ }
+
+ void sendMessage(ProducerRecord<Bytes, Bytes> record)
+ {
+ testRecordProducer.send(record, (metadata, e) ->
+ {
+ if (metadata != null)
+ {
+ log.debug(
+ "{}|{} - {}={}",
+ metadata.partition(),
+ metadata.offset(),
+ record.key(),
+ record.value());
+ }
+ else
+ {
+ log.warn(
+ "Exception for {}={}: {}",
+ record.key(),
+ record.value(),
+ e.toString());
+ }
+ });
+ }
+
+
+ @BeforeEach
+ public void init()
+ {
+ Properties props;
+ props = new Properties();
+ props.put("bootstrap.servers", properties.getBootstrapServer());
+ props.put("linger.ms", 100);
+ props.put("key.serializer", BytesSerializer.class.getName());
+ props.put("value.serializer", BytesSerializer.class.getName());
+ testRecordProducer = new KafkaProducer<>(props);
+
+ props = new Properties();
+ props.put("bootstrap.servers", properties.getBootstrapServer());
+ props.put("client.id", "OFFSET-CONSUMER");
+ props.put("group.id", properties.getGroupId());
+ props.put("key.deserializer", BytesDeserializer.class.getName());
+ props.put("value.deserializer", BytesDeserializer.class.getName());
+ offsetConsumer = new KafkaConsumer<>(props);
+
+ seekToEnd();
+
+ oldOffsets = new HashMap<>();
+ newOffsets = new HashMap<>();
+ receivedRecords = new HashSet<>();
+
+ doForCurrentOffsets((tp, offset) ->
+ {
+ oldOffsets.put(tp, offset - 1);
+ newOffsets.put(tp, offset - 1);
+ });
+
+ TestRecordHandler<K, V> captureOffsetAndExecuteTestHandler =
+ new TestRecordHandler<K, V>(recordHandler)
+ {
+ @Override
+ public void onNewRecord(ConsumerRecord<K, V> record)
+ {
+ newOffsets.put(
+ new TopicPartition(record.topic(), record.partition()),
+ record.offset());
+ receivedRecords.add(record);
+ }
+ };
+
+ endlessConsumer =
+ new EndlessConsumer<>(
+ executor,
+ properties.getClientId(),
+ properties.getTopic(),
+ kafkaConsumer,
+ rebalanceListener,
+ captureOffsetAndExecuteTestHandler);
+
+ endlessConsumer.start();
+ }
+
+ @AfterEach
+ public void deinit()
+ {
+ try
+ {
+ endlessConsumer.stop();
+ testRecordProducer.close();
+ offsetConsumer.close();
+ }
+ catch (Exception e)
+ {
+ log.info("Exception while stopping the consumer: {}", e.toString());
+ }
+ }
+
+
+ @TestConfiguration
+ @Import(ApplicationConfiguration.class)
+ public static class Configuration
+ {
+ }
+ }
projects / demos / kafka / training / commitdiff