Merge pull request #14945 from aamolgote/kafka/message-ordering-BAEL-6796

Message Ordering - First Draft.

apache-kafka-2/log4j.properties

@@ -1 +0,0 @@
-log4j.rootLogger=INFO, stdout

apache-kafka-2/pom.xml

@@ -23,11 +23,6 @@
             <artifactId>slf4j-api</artifactId>
             <version>${org.slf4j.version}</version>
         </dependency>
-        <dependency>
-            <groupId>org.slf4j</groupId>
-            <artifactId>slf4j-log4j12</artifactId>
-            <version>${org.slf4j.version}</version>
-        </dependency>
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
@@ -57,6 +52,11 @@
             <version>${lombok.version}</version>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>${jackson.databind.version} </version>
+        </dependency>
     </dependencies>
 
     <properties>
@@ -64,6 +64,7 @@
         <kafka.version>2.8.0</kafka.version>
         <testcontainers-kafka.version>1.15.3</testcontainers-kafka.version>
         <testcontainers-jupiter.version>1.15.3</testcontainers-jupiter.version>
+        <jackson.databind.version>2.15.2</jackson.databind.version>
     </properties>
 
 </project>

apache-kafka-2/src/main/java/com/baeldung/kafka/message/ordering/Config.java

@@ -0,0 +1,11 @@
+package com.baeldung.kafka.message.ordering;
+
+public class Config {
+    public static final String CONSUMER_VALUE_DESERIALIZER_SERIALIZED_CLASS = "value.deserializer.serializedClass";
+    public static final String MULTI_PARTITION_TOPIC = "multi_partition_topic";
+    public static final String SINGLE_PARTITION_TOPIC = "single_partition_topic";
+
+    public static final int MULTIPLE_PARTITIONS = 5;
+    public static final int SINGLE_PARTITION = 1;
+    public static final short REPLICATION_FACTOR = 1;
+}

apache-kafka-2/src/main/java/com/baeldung/kafka/message/ordering/payload/UserEvent.java

@@ -0,0 +1,61 @@
+package com.baeldung.kafka.message.ordering.payload;
+
+import java.util.Objects;
+
+public class UserEvent implements Comparable<UserEvent> {
+    private String userEventId;
+    private long eventNanoTime;
+    private long globalSequenceNumber;
+
+    @SuppressWarnings("unused")
+    public UserEvent() {
+        // Required for Jackson Serialization and Deserialization
+    }
+
+    public UserEvent(String userEventId) {
+        this.userEventId = userEventId;
+    }
+
+    public String getUserEventId() {
+        return userEventId;
+    }
+
+    public long getEventNanoTime() {
+        return eventNanoTime;
+    }
+
+    public void setEventNanoTime(long eventNanoTime) {
+        this.eventNanoTime = eventNanoTime;
+    }
+
+    public long getGlobalSequenceNumber() {
+        return globalSequenceNumber;
+    }
+
+    public void setGlobalSequenceNumber(long globalSequenceNumber) {
+        this.globalSequenceNumber = globalSequenceNumber;
+    }
+
+    @Override
+    public int compareTo(UserEvent other) {
+        return Long.compare(this.globalSequenceNumber, other.globalSequenceNumber);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof UserEvent)) {
+            return false;
+        }
+        UserEvent userEvent = (UserEvent) obj;
+        return this.globalSequenceNumber == userEvent.globalSequenceNumber;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(globalSequenceNumber);
+    }
+}
+

apache-kafka-2/src/main/java/com/baeldung/kafka/message/ordering/serialization/JacksonDeserializer.java

@@ -0,0 +1,34 @@
+package com.baeldung.kafka.message.ordering.serialization;
+
+import com.baeldung.kafka.message.ordering.Config;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import org.apache.kafka.common.serialization.Deserializer;
+
+import java.util.Map;
+
+/**
+ * Configured via {@link org.apache.kafka.clients.consumer.ConsumerConfig#VALUE_DESERIALIZER_CLASS_CONFIG}
+ */
+public class JacksonDeserializer<T> implements Deserializer<T> {
+    private final ObjectMapper objectMapper = new ObjectMapper();
+    private Class<T> type;
+
+    @Override
+    public void configure(Map<String, ?> configs, boolean isKey) {
+        this.type = (Class<T>) configs.get(Config.CONSUMER_VALUE_DESERIALIZER_SERIALIZED_CLASS);
+    }
+
+    @Override
+    public T deserialize(String topic, byte[] bytes) {
+        if (bytes == null) {
+            return null;
+        }
+        try {
+            return objectMapper.readValue(bytes, type);
+        } catch (Exception e) {
+            throw new RuntimeException("Error deserializing value", e);
+        }
+    }
+}
+

apache-kafka-2/src/main/java/com/baeldung/kafka/message/ordering/serialization/JacksonSerializer.java

@@ -0,0 +1,24 @@
+package com.baeldung.kafka.message.ordering.serialization;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import org.apache.kafka.common.serialization.Serializer;
+
+/**
+ * Configured via {@link org.apache.kafka.clients.producer.ProducerConfig#VALUE_SERIALIZER_CLASS_CONFIG}
+ */
+public class JacksonSerializer<T> implements Serializer<T> {
+    private final ObjectMapper objectMapper = new ObjectMapper();
+
+    @Override
+    public byte[] serialize(String topic, T data) {
+        if (data == null) {
+            return null;
+        }
+        try {
+            return objectMapper.writeValueAsBytes(data);
+        } catch (Exception e) {
+            throw new RuntimeException("Error serializing value", e);
+        }
+    }
+}

apache-kafka-2/src/test/java/com/baeldung/kafka/message/ordering/ExternalSequenceWithTimeWindowLiveTest.java

@@ -0,0 +1,126 @@
+package com.baeldung.kafka.message.ordering;
+
+import com.baeldung.kafka.message.ordering.payload.UserEvent;
+import com.baeldung.kafka.message.ordering.serialization.JacksonDeserializer;
+import com.baeldung.kafka.message.ordering.serialization.JacksonSerializer;
+
+import org.apache.kafka.clients.admin.*;
+import org.apache.kafka.clients.consumer.ConsumerConfig;
+import org.apache.kafka.clients.consumer.ConsumerRecords;
+import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.clients.producer.KafkaProducer;
+import org.apache.kafka.clients.producer.ProducerConfig;
+import org.apache.kafka.clients.producer.ProducerRecord;
+import org.apache.kafka.clients.producer.RecordMetadata;
+import org.apache.kafka.common.serialization.LongDeserializer;
+import org.apache.kafka.common.serialization.LongSerializer;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.testcontainers.containers.KafkaContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+import org.testcontainers.utility.DockerImageName;
+
+import java.time.Duration;
+import java.util.*;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+
+import com.google.common.collect.ImmutableList;
+
+import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
+
+@Testcontainers
+public class ExternalSequenceWithTimeWindowLiveTest {
+
+    private static Admin admin;
+    private static KafkaProducer<Long, UserEvent> producer;
+    private static KafkaConsumer<Long, UserEvent> consumer;
+    private static final Duration TIMEOUT_WAIT_FOR_MESSAGES = Duration.ofSeconds(5);
+    private static final long BUFFER_PERIOD_NS = Duration.ofSeconds(5)
+        .toNanos();
+    private static Logger logger = LoggerFactory.getLogger(ExternalSequenceWithTimeWindowLiveTest.class);
+
+    @Container
+    private static final KafkaContainer KAFKA_CONTAINER = new KafkaContainer(DockerImageName.parse("confluentinc/cp-kafka:latest"));
+
+    @BeforeAll
+    static void setup() throws ExecutionException, InterruptedException {
+        KAFKA_CONTAINER.addExposedPort(9092);
+
+        Properties adminProperties = new Properties();
+        adminProperties.put(AdminClientConfig.BOOTSTRAP_SERVERS_CONFIG, KAFKA_CONTAINER.getBootstrapServers());
+
+        Properties producerProperties = new Properties();
+        producerProperties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, KAFKA_CONTAINER.getBootstrapServers());
+        producerProperties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, LongSerializer.class.getName());
+        producerProperties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, JacksonSerializer.class.getName());
+
+        Properties consumerProperties = new Properties();
+        consumerProperties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, KAFKA_CONTAINER.getBootstrapServers());
+        consumerProperties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, LongDeserializer.class.getName());
+        consumerProperties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, JacksonDeserializer.class.getName());
+        consumerProperties.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
+        consumerProperties.put(Config.CONSUMER_VALUE_DESERIALIZER_SERIALIZED_CLASS, UserEvent.class);
+        consumerProperties.put(ConsumerConfig.GROUP_ID_CONFIG, "test-group");
+        admin = Admin.create(adminProperties);
+        producer = new KafkaProducer<>(producerProperties);
+        consumer = new KafkaConsumer<>(consumerProperties);
+        admin.createTopics(ImmutableList.of(new NewTopic(Config.MULTI_PARTITION_TOPIC, Config.MULTIPLE_PARTITIONS, Config.REPLICATION_FACTOR)))
+            .all()
+            .get();
+    }
+
+    @AfterAll
+    static void destroy() {
+        KAFKA_CONTAINER.stop();
+    }
+
+    @Test
+    void givenMultiplePartitions_whenPublishedToKafkaAndConsumedWithExtSeqNumberAndTimeWindow_thenCheckForMessageOrder() throws ExecutionException, InterruptedException {
+        List<UserEvent> sentUserEventList = new ArrayList<>();
+        List<UserEvent> receivedUserEventList = new ArrayList<>();
+        for (long sequenceNumber = 1; sequenceNumber <= 10; sequenceNumber++) {
+            UserEvent userEvent = new UserEvent(UUID.randomUUID()
+                .toString());
+            userEvent.setEventNanoTime(System.nanoTime());
+            userEvent.setGlobalSequenceNumber(sequenceNumber);
+            Future<RecordMetadata> future = producer.send(new ProducerRecord<>(Config.MULTI_PARTITION_TOPIC, sequenceNumber, userEvent));
+            sentUserEventList.add(userEvent);
+            RecordMetadata metadata = future.get();
+            logger.info("User Event ID: " + userEvent.getUserEventId() + ", Partition : " + metadata.partition());
+        }
+
+        consumer.subscribe(Collections.singletonList(Config.MULTI_PARTITION_TOPIC));
+        List<UserEvent> buffer = new ArrayList<>();
+        long lastProcessedTime = System.nanoTime();
+        ConsumerRecords<Long, UserEvent> records = consumer.poll(TIMEOUT_WAIT_FOR_MESSAGES);
+        records.forEach(record -> {
+            buffer.add(record.value());
+        });
+        while (!buffer.isEmpty()) {
+            if (System.nanoTime() - lastProcessedTime > BUFFER_PERIOD_NS) {
+                processBuffer(buffer, receivedUserEventList);
+                lastProcessedTime = System.nanoTime();
+            }
+            records = consumer.poll(TIMEOUT_WAIT_FOR_MESSAGES);
+            records.forEach(record -> {
+                buffer.add(record.value());
+            });
+        }
+        assertThat(receivedUserEventList).isEqualTo(sentUserEventList)
+            .containsExactlyElementsOf(sentUserEventList);
+    }
+
+    private static void processBuffer(List<UserEvent> buffer, List<UserEvent> receivedUserEventList) {
+        Collections.sort(buffer);
+        buffer.forEach(userEvent -> {
+            receivedUserEventList.add(userEvent);
+            logger.info("Processing message with Global Sequence number: " + userEvent.getGlobalSequenceNumber() + ", User Event Id: " + userEvent.getUserEventId());
+        });
+        buffer.clear();
+    }
+}

apache-kafka-2/src/test/java/com/baeldung/kafka/message/ordering/MultiplePartitionLiveTest.java

@@ -0,0 +1,105 @@
+package com.baeldung.kafka.message.ordering;
+
+import com.baeldung.kafka.message.ordering.payload.UserEvent;
+import com.baeldung.kafka.message.ordering.serialization.JacksonDeserializer;
+import com.baeldung.kafka.message.ordering.serialization.JacksonSerializer;
+
+import org.apache.kafka.clients.admin.*;
+import org.apache.kafka.clients.consumer.ConsumerConfig;
+import org.apache.kafka.clients.consumer.ConsumerRecords;
+import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.clients.producer.KafkaProducer;
+import org.apache.kafka.clients.producer.ProducerConfig;
+import org.apache.kafka.clients.producer.ProducerRecord;
+import org.apache.kafka.clients.producer.RecordMetadata;
+import org.apache.kafka.common.serialization.LongDeserializer;
+import org.apache.kafka.common.serialization.LongSerializer;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.testcontainers.containers.KafkaContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+import org.testcontainers.utility.DockerImageName;
+
+import java.time.Duration;
+import java.util.*;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+
+import com.google.common.collect.ImmutableList;
+
+import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
+
+@Testcontainers
+public class MultiplePartitionLiveTest {
+
+    private static Admin admin;
+    private static KafkaProducer<Long, UserEvent> producer;
+    private static KafkaConsumer<Long, UserEvent> consumer;
+    private static final Duration TIMEOUT_WAIT_FOR_MESSAGES = Duration.ofSeconds(5);
+
+    private static Logger logger = LoggerFactory.getLogger(MultiplePartitionLiveTest.class);
+    @Container
+    private static final KafkaContainer KAFKA_CONTAINER = new KafkaContainer(DockerImageName.parse("confluentinc/cp-kafka:latest"));
+
+    @BeforeAll
+    static void setup() throws ExecutionException, InterruptedException {
+        KAFKA_CONTAINER.addExposedPort(9092);
+
+        Properties adminProperties = new Properties();
+        adminProperties.put(AdminClientConfig.BOOTSTRAP_SERVERS_CONFIG, KAFKA_CONTAINER.getBootstrapServers());
+
+        Properties producerProperties = new Properties();
+        producerProperties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, KAFKA_CONTAINER.getBootstrapServers());
+        producerProperties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, LongSerializer.class.getName());
+        producerProperties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, JacksonSerializer.class.getName());
+
+        Properties consumerProperties = new Properties();
+        consumerProperties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, KAFKA_CONTAINER.getBootstrapServers());
+        consumerProperties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, LongDeserializer.class.getName());
+        consumerProperties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, JacksonDeserializer.class.getName());
+        consumerProperties.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
+        consumerProperties.put(Config.CONSUMER_VALUE_DESERIALIZER_SERIALIZED_CLASS, UserEvent.class);
+        consumerProperties.put(ConsumerConfig.GROUP_ID_CONFIG, "test-group");
+        admin = Admin.create(adminProperties);
+        producer = new KafkaProducer<>(producerProperties);
+        consumer = new KafkaConsumer<>(consumerProperties);
+        admin.createTopics(ImmutableList.of(new NewTopic(Config.MULTI_PARTITION_TOPIC, Config.MULTIPLE_PARTITIONS, Config.REPLICATION_FACTOR)))
+            .all()
+            .get();
+    }
+
+    @AfterAll
+    static void destroy() {
+        KAFKA_CONTAINER.stop();
+    }
+
+    @Test
+    void givenMultiplePartitions_whenPublishedToKafkaAndConsumed_thenCheckForMessageOrder() throws ExecutionException, InterruptedException {
+        List<UserEvent> sentUserEventList = new ArrayList<>();
+        List<UserEvent> receivedUserEventList = new ArrayList<>();
+        for (long sequenceNumber = 1; sequenceNumber <= 10; sequenceNumber++) {
+            UserEvent userEvent = new UserEvent(UUID.randomUUID()
+                .toString());
+            userEvent.setGlobalSequenceNumber(sequenceNumber);
+            userEvent.setEventNanoTime(System.nanoTime());
+            Future<RecordMetadata> future = producer.send(new ProducerRecord<>(Config.MULTI_PARTITION_TOPIC, sequenceNumber, userEvent));
+            sentUserEventList.add(userEvent);
+            RecordMetadata metadata = future.get();
+            logger.info("User Event ID: " + userEvent.getUserEventId() + ", Partition : " + metadata.partition());
+        }
+
+        consumer.subscribe(Collections.singletonList(Config.MULTI_PARTITION_TOPIC));
+        ConsumerRecords<Long, UserEvent> records = consumer.poll(TIMEOUT_WAIT_FOR_MESSAGES);
+        records.forEach(record -> {
+            UserEvent userEvent = record.value();
+            receivedUserEventList.add(userEvent);
+            logger.info("User Event ID: " + userEvent.getUserEventId());
+        });
+        assertThat(receivedUserEventList).isNotEqualTo(sentUserEventList)
+            .containsExactlyInAnyOrderElementsOf(sentUserEventList);
+    }
+}

apache-kafka-2/src/test/java/com/baeldung/kafka/message/ordering/SinglePartitionLiveTest.java

@@ -0,0 +1,109 @@
+package com.baeldung.kafka.message.ordering;
+
+import com.baeldung.kafka.message.ordering.payload.UserEvent;
+import com.baeldung.kafka.message.ordering.serialization.JacksonDeserializer;
+import com.baeldung.kafka.message.ordering.serialization.JacksonSerializer;
+
+import org.apache.kafka.clients.admin.Admin;
+import org.apache.kafka.clients.admin.AdminClientConfig;
+import org.apache.kafka.clients.admin.NewTopic;
+import org.apache.kafka.clients.consumer.ConsumerConfig;
+import org.apache.kafka.clients.consumer.ConsumerRecords;
+import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.clients.producer.KafkaProducer;
+import org.apache.kafka.clients.producer.ProducerConfig;
+import org.apache.kafka.clients.producer.ProducerRecord;
+import org.apache.kafka.clients.producer.RecordMetadata;
+import org.apache.kafka.common.serialization.LongDeserializer;
+import org.apache.kafka.common.serialization.LongSerializer;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.testcontainers.containers.KafkaContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+import org.testcontainers.utility.DockerImageName;
+
+import java.time.Duration;
+import java.util.*;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+
+import com.google.common.collect.ImmutableList;
+
+import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
+
+@Testcontainers
+public class SinglePartitionLiveTest {
+
+    private static Admin admin;
+    private static KafkaProducer<Long, UserEvent> producer;
+    private static KafkaConsumer<Long, UserEvent> consumer;
+
+    private static final Duration TIMEOUT_WAIT_FOR_MESSAGES = Duration.ofSeconds(5);
+
+    private static Logger logger = LoggerFactory.getLogger(SinglePartitionLiveTest.class);
+    @Container
+    private static final KafkaContainer KAFKA_CONTAINER = new KafkaContainer(DockerImageName.parse("confluentinc/cp-kafka:latest"));
+
+    @BeforeAll
+    static void setup() throws ExecutionException, InterruptedException {
+        KAFKA_CONTAINER.addExposedPort(9092);
+
+        Properties adminProperties = new Properties();
+        adminProperties.put(AdminClientConfig.BOOTSTRAP_SERVERS_CONFIG, KAFKA_CONTAINER.getBootstrapServers());
+
+        Properties producerProperties = new Properties();
+        producerProperties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, KAFKA_CONTAINER.getBootstrapServers());
+        producerProperties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, LongSerializer.class.getName());
+        producerProperties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, JacksonSerializer.class.getName());
+
+        Properties consumerProperties = new Properties();
+        consumerProperties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, KAFKA_CONTAINER.getBootstrapServers());
+        consumerProperties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, LongDeserializer.class.getName());
+        consumerProperties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, JacksonDeserializer.class.getName());
+        consumerProperties.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
+        consumerProperties.put(Config.CONSUMER_VALUE_DESERIALIZER_SERIALIZED_CLASS, UserEvent.class);
+        consumerProperties.put(ConsumerConfig.GROUP_ID_CONFIG, "test-group");
+        admin = Admin.create(adminProperties);
+        producer = new KafkaProducer<>(producerProperties);
+        consumer = new KafkaConsumer<>(consumerProperties);
+        admin.createTopics(ImmutableList.of(new NewTopic(Config.SINGLE_PARTITION_TOPIC, Config.SINGLE_PARTITION, Config.REPLICATION_FACTOR)))
+            .all()
+            .get();
+    }
+
+    @AfterAll
+    static void destroy() {
+        KAFKA_CONTAINER.stop();
+    }
+
+    @Test
+    void givenASinglePartition_whenPublishedToKafkaAndConsumed_thenCheckForMessageOrder() throws ExecutionException, InterruptedException {
+        List<UserEvent> sentUserEventList = new ArrayList<>();
+        List<UserEvent> receivedUserEventList = new ArrayList<>();
+        for (long sequenceNumber = 1; sequenceNumber <= 10; sequenceNumber++) {
+            UserEvent userEvent = new UserEvent(UUID.randomUUID()
+                .toString());
+            userEvent.setGlobalSequenceNumber(sequenceNumber);
+            userEvent.setEventNanoTime(System.nanoTime());
+            ProducerRecord<Long, UserEvent> producerRecord = new ProducerRecord<>(Config.SINGLE_PARTITION_TOPIC, userEvent);
+            Future<RecordMetadata> future = producer.send(producerRecord);
+            sentUserEventList.add(userEvent);
+            RecordMetadata metadata = future.get();
+            logger.info("User Event ID: " + userEvent.getUserEventId() + ", Partition : " + metadata.partition());
+        }
+
+        consumer.subscribe(Collections.singletonList(Config.SINGLE_PARTITION_TOPIC));
+        ConsumerRecords<Long, UserEvent> records = consumer.poll(TIMEOUT_WAIT_FOR_MESSAGES);
+        records.forEach(record -> {
+            UserEvent userEvent = record.value();
+            receivedUserEventList.add(userEvent);
+            logger.info("User Event ID: " + userEvent.getUserEventId());
+        });
+        assertThat(receivedUserEventList).isEqualTo(sentUserEventList)
+            .containsExactlyElementsOf(sentUserEventList);
+    }
+}

apache-kafka-2/src/test/resources/logback.xml

@@ -0,0 +1,11 @@
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>