Verbesserungen aus 'stored-state' nach 'rebalance-listener' gemerged
authorKai Moritz <kai@juplo.de>
Sat, 13 Aug 2022 08:48:49 +0000 (10:48 +0200)
committerKai Moritz <kai@juplo.de>
Sat, 13 Aug 2022 09:15:22 +0000 (11:15 +0200)
15 files changed:
docker-compose.yml
pom.xml
src/main/java/de/juplo/kafka/Application.java
src/main/java/de/juplo/kafka/ApplicationConfiguration.java [new file with mode: 0644]
src/main/java/de/juplo/kafka/ApplicationHealthIndicator.java
src/main/java/de/juplo/kafka/ApplicationProperties.java
src/main/java/de/juplo/kafka/DriverController.java
src/main/java/de/juplo/kafka/EndlessConsumer.java
src/main/java/de/juplo/kafka/KeyCountingRebalanceListener.java [new file with mode: 0644]
src/main/java/de/juplo/kafka/KeyCountingRecordHandler.java [new file with mode: 0644]
src/main/java/de/juplo/kafka/RecordHandler.java [new file with mode: 0644]
src/main/resources/application.yml
src/test/java/de/juplo/kafka/ApplicationIT.java [new file with mode: 0644]
src/test/java/de/juplo/kafka/ApplicationTests.java [new file with mode: 0644]
src/test/java/de/juplo/kafka/TestRecordHandler.java [new file with mode: 0644]

index 1b067cd..df6b321 100644 (file)
@@ -37,14 +37,13 @@ services:
     command: sleep infinity
 
   producer:
-    image: juplo/endless-producer:1.0-SNAPSHOT
+    image: juplo/endless-long-producer:1.0-SNAPSHOT
     ports:
       - 8080:8080
     environment:
       server.port: 8080
       producer.bootstrap-server: kafka:9092
       producer.client-id: producer
-      producer.topic: test
       producer.throttle-ms: 10
 
 
@@ -55,6 +54,4 @@ services:
     environment:
       server.port: 8080
       consumer.bootstrap-server: kafka:9092
-      consumer.client-id: my-group
       consumer.client-id: consumer
-      consumer.topic: test
diff --git a/pom.xml b/pom.xml
index 9db9d9d..1f5caab 100644 (file)
--- a/pom.xml
+++ b/pom.xml
       <artifactId>spring-boot-starter-test</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.springframework.kafka</groupId>
+      <artifactId>spring-kafka-test</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.awaitility</groupId>
+      <artifactId>awaitility</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <build>
index de4b66d..76c2520 100644 (file)
@@ -1,39 +1,76 @@
 package de.juplo.kafka;
 
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.ApplicationArguments;
+import org.springframework.boot.ApplicationRunner;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
-import org.springframework.boot.context.properties.EnableConfigurationProperties;
-import org.springframework.context.annotation.Bean;
 
-import java.util.concurrent.Executors;
+import javax.annotation.PreDestroy;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.TimeUnit;
 
 
 @SpringBootApplication
-@EnableConfigurationProperties(ApplicationProperties.class)
-public class Application
+@Slf4j
+public class Application implements ApplicationRunner
 {
   @Autowired
-  ApplicationProperties properties;
+  EndlessConsumer endlessConsumer;
+  @Autowired
+  ExecutorService executor;
+
 
+  @Override
+  public void run(ApplicationArguments args) throws Exception
+  {
+    log.info("Starting EndlessConsumer");
+    endlessConsumer.start();
+  }
 
-  @Bean
-  public EndlessConsumer consumer()
+  @PreDestroy
+  public void shutdown()
   {
-    EndlessConsumer consumer =
-        new EndlessConsumer(
-            Executors.newFixedThreadPool(1),
-            properties.getBootstrapServer(),
-            properties.getGroupId(),
-            properties.getClientId(),
-            properties.getTopic(),
-            properties.getAutoOffsetReset());
-
-    consumer.start();
-
-    return consumer;
+    try
+    {
+      log.info("Stopping EndlessConsumer");
+      endlessConsumer.stop();
+    }
+    catch (IllegalStateException e)
+    {
+      log.info("Was already stopped: {}", e.toString());
+    }
+    catch (Exception e)
+    {
+      log.error("Unexpected exception while stopping EndlessConsumer: {}", e);
+    }
+
+    try
+    {
+      log.info("Shutting down the ExecutorService.");
+      executor.shutdown();
+      log.info("Waiting 5 seconds for the ExecutorService to terminate...");
+      executor.awaitTermination(5, TimeUnit.SECONDS);
+    }
+    catch (InterruptedException e)
+    {
+      log.error("Exception while waiting for the termination of the ExecutorService: {}", e);
+    }
+    finally
+    {
+      if (!executor.isTerminated())
+      {
+        log.warn("Forcing shutdown of ExecutorService!");
+        executor
+            .shutdownNow()
+            .forEach(runnable -> log.warn("Unprocessed task: {}", runnable.getClass().getSimpleName()));
+      }
+      log.info("Shutdow of ExecutorService finished");
+    }
   }
 
+
   public static void main(String[] args)
   {
     SpringApplication.run(Application.class, args);
diff --git a/src/main/java/de/juplo/kafka/ApplicationConfiguration.java b/src/main/java/de/juplo/kafka/ApplicationConfiguration.java
new file mode 100644 (file)
index 0000000..7a0a8ad
--- /dev/null
@@ -0,0 +1,76 @@
+package de.juplo.kafka;
+
+import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.common.serialization.LongDeserializer;
+import org.apache.kafka.common.serialization.StringDeserializer;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import java.util.Properties;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+
+@Configuration
+@EnableConfigurationProperties(ApplicationProperties.class)
+public class ApplicationConfiguration
+{
+  @Bean
+  public KeyCountingRecordHandler keyCountingRecordHandler()
+  {
+    return new KeyCountingRecordHandler();
+  }
+
+  @Bean
+  public KeyCountingRebalanceListener keyCountingRebalanceListener(
+      KeyCountingRecordHandler keyCountingRecordHandler,
+      ApplicationProperties properties)
+  {
+    return new KeyCountingRebalanceListener(
+        keyCountingRecordHandler,
+        properties.getClientId());
+  }
+
+  @Bean
+  public EndlessConsumer<String, Long> endlessConsumer(
+      KafkaConsumer<String, Long> kafkaConsumer,
+      ExecutorService executor,
+      KeyCountingRebalanceListener keyCountingRebalanceListener,
+      KeyCountingRecordHandler keyCountingRecordHandler,
+      ApplicationProperties properties)
+  {
+    return
+        new EndlessConsumer<>(
+            executor,
+            properties.getClientId(),
+            properties.getTopic(),
+            kafkaConsumer,
+            keyCountingRebalanceListener,
+            keyCountingRecordHandler);
+  }
+
+  @Bean
+  public ExecutorService executor()
+  {
+    return Executors.newSingleThreadExecutor();
+  }
+
+  @Bean(destroyMethod = "close")
+  public KafkaConsumer<String, Long> kafkaConsumer(ApplicationProperties properties)
+  {
+    Properties props = new Properties();
+
+    props.put("bootstrap.servers", properties.getBootstrapServer());
+    props.put("partition.assignment.strategy", "org.apache.kafka.clients.consumer.CooperativeStickyAssignor");
+    props.put("group.id", properties.getGroupId());
+    props.put("client.id", properties.getClientId());
+    props.put("auto.offset.reset", properties.getAutoOffsetReset());
+    props.put("auto.commit.interval.ms", (int)properties.getCommitInterval().toMillis());
+    props.put("metadata.max.age.ms", "1000");
+    props.put("key.deserializer", StringDeserializer.class.getName());
+    props.put("value.deserializer", LongDeserializer.class.getName());
+
+    return new KafkaConsumer<>(props);
+  }
+}
index ab9782c..dc3a26e 100644 (file)
@@ -10,7 +10,7 @@ import org.springframework.stereotype.Component;
 @RequiredArgsConstructor
 public class ApplicationHealthIndicator implements HealthIndicator
 {
-  private final EndlessConsumer consumer;
+  private final EndlessConsumer<String, Long> consumer;
 
 
   @Override
index fa731c5..14e928f 100644 (file)
@@ -7,6 +7,7 @@ import org.springframework.validation.annotation.Validated;
 
 import javax.validation.constraints.NotEmpty;
 import javax.validation.constraints.NotNull;
+import java.time.Duration;
 
 
 @ConfigurationProperties(prefix = "consumer")
@@ -30,4 +31,6 @@ public class ApplicationProperties
   @NotNull
   @NotEmpty
   private String autoOffsetReset;
+  @NotNull
+  private Duration commitInterval;
 }
index 1fb2a1b..f6ff47f 100644 (file)
@@ -2,11 +2,7 @@ package de.juplo.kafka;
 
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.HttpStatus;
-import org.springframework.web.bind.annotation.ExceptionHandler;
-import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.PostMapping;
-import org.springframework.web.bind.annotation.ResponseStatus;
-import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.bind.annotation.*;
 
 import java.util.Map;
 import java.util.concurrent.ExecutionException;
@@ -17,6 +13,7 @@ import java.util.concurrent.ExecutionException;
 public class DriverController
 {
   private final EndlessConsumer consumer;
+  private final KeyCountingRecordHandler keyCountingRecordHandler;
 
 
   @PostMapping("start")
@@ -33,9 +30,9 @@ public class DriverController
 
 
   @GetMapping("seen")
-  public Map<Integer, Map<String, Integer>> seen()
+  public Map<Integer, Map<String, Long>> seen()
   {
-    return consumer.getSeen();
+    return keyCountingRecordHandler.getSeen();
   }
 
 
index c2d4447..c7579b8 100644 (file)
@@ -1,13 +1,11 @@
 package de.juplo.kafka;
 
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.apache.kafka.clients.consumer.ConsumerRebalanceListener;
-import org.apache.kafka.clients.consumer.ConsumerRecord;
-import org.apache.kafka.clients.consumer.ConsumerRecords;
-import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.clients.consumer.*;
 import org.apache.kafka.common.TopicPartition;
+import org.apache.kafka.common.errors.RecordDeserializationException;
 import org.apache.kafka.common.errors.WakeupException;
-import org.apache.kafka.common.serialization.StringDeserializer;
 
 import javax.annotation.PreDestroy;
 import java.time.Duration;
@@ -20,101 +18,41 @@ import java.util.concurrent.locks.ReentrantLock;
 
 
 @Slf4j
-public class EndlessConsumer implements Runnable
+@RequiredArgsConstructor
+public class EndlessConsumer<K, V> implements Runnable
 {
   private final ExecutorService executor;
-  private final String bootstrapServer;
-  private final String groupId;
   private final String id;
   private final String topic;
-  private final String autoOffsetReset;
+  private final Consumer<K, V> consumer;
+  private final ConsumerRebalanceListener consumerRebalanceListener;
+  private final RecordHandler<K, V> handler;
 
   private final Lock lock = new ReentrantLock();
   private final Condition condition = lock.newCondition();
   private boolean running = false;
   private Exception exception;
   private long consumed = 0;
-  private KafkaConsumer<String, String> consumer = null;
 
 
-  private final Map<Integer, Map<String, Integer>> seen = new HashMap<>();
-
-
-  public EndlessConsumer(
-      ExecutorService executor,
-      String bootstrapServer,
-      String groupId,
-      String clientId,
-      String topic,
-      String autoOffsetReset)
-  {
-    this.executor = executor;
-    this.bootstrapServer = bootstrapServer;
-    this.groupId = groupId;
-    this.id = clientId;
-    this.topic = topic;
-    this.autoOffsetReset = autoOffsetReset;
-  }
 
   @Override
   public void run()
   {
     try
     {
-      Properties props = new Properties();
-      props.put("bootstrap.servers", bootstrapServer);
-      props.put("group.id", groupId);
-      props.put("client.id", id);
-      props.put("auto.offset.reset", autoOffsetReset);
-      props.put("metadata.max.age.ms", "1000");
-      props.put("key.deserializer", StringDeserializer.class.getName());
-      props.put("value.deserializer", StringDeserializer.class.getName());
-
-      this.consumer = new KafkaConsumer<>(props);
-
       log.info("{} - Subscribing to topic {}", id, topic);
-      consumer.subscribe(Arrays.asList(topic), new ConsumerRebalanceListener()
-      {
-        @Override
-        public void onPartitionsRevoked(Collection<TopicPartition> partitions)
-        {
-          partitions.forEach(tp ->
-          {
-            log.info("{} - removing partition: {}", id, tp);
-            Map<String, Integer> removed = seen.remove(tp.partition());
-            for (String key : removed.keySet())
-            {
-              log.info(
-                  "{} - Seen {} messages for partition={}|key={}",
-                  id,
-                  removed.get(key),
-                  tp.partition(),
-                  key);
-            }
-          });
-        }
-
-        @Override
-        public void onPartitionsAssigned(Collection<TopicPartition> partitions)
-        {
-          partitions.forEach(tp ->
-          {
-            log.info("{} - adding partition: {}", id, tp);
-            seen.put(tp.partition(), new HashMap<>());
-          });
-        }
-      });
+      consumer.subscribe(Arrays.asList(topic), consumerRebalanceListener);
 
       while (true)
       {
-        ConsumerRecords<String, String> records =
+        ConsumerRecords<K, V> records =
             consumer.poll(Duration.ofSeconds(1));
 
         // Do something with the data...
         log.info("{} - Received {} messages", id, records.count());
-        for (ConsumerRecord<String, String> record : records)
+        for (ConsumerRecord<K, V> record : records)
         {
-          consumed++;
           log.info(
               "{} - {}: {}/{} - {}={}",
               id,
@@ -125,24 +63,32 @@ public class EndlessConsumer implements Runnable
               record.value()
           );
 
-          Integer partition = record.partition();
-          String key = record.key() == null ? "NULL" : record.key();
-          Map<String, Integer> byKey = seen.get(partition);
+          handler.accept(record);
 
-          if (!byKey.containsKey(key))
-            byKey.put(key, 0);
-
-          int seenByKey = byKey.get(key);
-          seenByKey++;
-          byKey.put(key, seenByKey);
+          consumed++;
         }
       }
     }
     catch(WakeupException e)
     {
-      log.info("{} - RIIING!", id);
+      log.info("{} - RIIING! Request to stop consumption - commiting current offsets!", id);
+      consumer.commitSync();
       shutdown();
     }
+    catch(RecordDeserializationException e)
+    {
+      TopicPartition tp = e.topicPartition();
+      long offset = e.offset();
+      log.error(
+          "{} - Could not deserialize  message on topic {} with offset={}: {}",
+          id,
+          tp,
+          offset,
+          e.getCause().toString());
+
+      consumer.commitSync();
+      shutdown(e);
+    }
     catch(Exception e)
     {
       log.error("{} - Unexpected error: {}", id, e.toString(), e);
@@ -150,8 +96,6 @@ public class EndlessConsumer implements Runnable
     }
     finally
     {
-      log.info("{} - Closing the KafkaConsumer", id);
-      consumer.close();
       log.info("{} - Consumer-Thread exiting", id);
     }
   }
@@ -166,9 +110,25 @@ public class EndlessConsumer implements Runnable
     lock.lock();
     try
     {
-      running = false;
-      exception = e;
-      condition.signal();
+      try
+      {
+        log.info("{} - Unsubscribing from topic {}", id, topic);
+        consumer.unsubscribe();
+      }
+      catch (Exception ue)
+      {
+        log.error(
+            "{} - Error while unsubscribing from topic {}: {}",
+            id,
+            topic,
+            ue.toString());
+      }
+      finally
+      {
+        running = false;
+        exception = e;
+        condition.signal();
+      }
     }
     finally
     {
@@ -176,11 +136,6 @@ public class EndlessConsumer implements Runnable
     }
   }
 
-  public Map<Integer, Map<String, Integer>> getSeen()
-  {
-    return seen;
-  }
-
   public void start()
   {
     lock.lock();
@@ -200,7 +155,7 @@ public class EndlessConsumer implements Runnable
     }
   }
 
-  public synchronized void stop() throws ExecutionException, InterruptedException
+  public synchronized void stop() throws InterruptedException
   {
     lock.lock();
     try
@@ -223,22 +178,7 @@ public class EndlessConsumer implements Runnable
   public void destroy() throws ExecutionException, InterruptedException
   {
     log.info("{} - Destroy!", id);
-    try
-    {
-      stop();
-    }
-    catch (IllegalStateException e)
-    {
-      log.info("{} - Was already stopped", id);
-    }
-    catch (Exception e)
-    {
-      log.error("{} - Unexpected exception while trying to stop the consumer", id, e);
-    }
-    finally
-    {
-      log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
-    }
+    log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
   }
 
   public boolean running()
diff --git a/src/main/java/de/juplo/kafka/KeyCountingRebalanceListener.java b/src/main/java/de/juplo/kafka/KeyCountingRebalanceListener.java
new file mode 100644 (file)
index 0000000..0ad1f31
--- /dev/null
@@ -0,0 +1,50 @@
+package de.juplo.kafka;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.kafka.clients.consumer.ConsumerRebalanceListener;
+import org.apache.kafka.common.TopicPartition;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+
+
+@RequiredArgsConstructor
+@Slf4j
+public class KeyCountingRebalanceListener implements ConsumerRebalanceListener
+{
+  private final KeyCountingRecordHandler handler;
+  private final String id;
+
+  @Override
+  public void onPartitionsAssigned(Collection<TopicPartition> partitions)
+  {
+    partitions.forEach(tp ->
+    {
+      Integer partition = tp.partition();
+      log.info("{} - adding partition: {}", id, partition);
+      handler.addPartition(partition, new HashMap<>());
+    });
+  }
+
+  @Override
+  public void onPartitionsRevoked(Collection<TopicPartition> partitions)
+  {
+    partitions.forEach(tp ->
+    {
+      Integer partition = tp.partition();
+      log.info("{} - removing partition: {}", id, partition);
+      Map<String, Long> removed = handler.removePartition(partition);
+      for (String key : removed.keySet())
+      {
+        log.info(
+            "{} - Seen {} messages for partition={}|key={}",
+            id,
+            removed.get(key),
+            partition,
+            key);
+      }
+    });
+  }
+}
diff --git a/src/main/java/de/juplo/kafka/KeyCountingRecordHandler.java b/src/main/java/de/juplo/kafka/KeyCountingRecordHandler.java
new file mode 100644 (file)
index 0000000..099dcf7
--- /dev/null
@@ -0,0 +1,46 @@
+package de.juplo.kafka;
+
+import lombok.extern.slf4j.Slf4j;
+import org.apache.kafka.clients.consumer.ConsumerRecord;
+
+import java.util.HashMap;
+import java.util.Map;
+
+
+@Slf4j
+public class KeyCountingRecordHandler implements RecordHandler<String, Long>
+{
+  private final Map<Integer, Map<String, Long>> seen = new HashMap<>();
+
+
+  @Override
+  public void accept(ConsumerRecord<String, Long> record)
+  {
+    Integer partition = record.partition();
+    String key = record.key() == null ? "NULL" : record.key().toString();
+    Map<String, Long> byKey = seen.get(partition);
+
+    if (!byKey.containsKey(key))
+      byKey.put(key, 0l);
+
+    long seenByKey = byKey.get(key);
+    seenByKey++;
+    byKey.put(key, seenByKey);
+  }
+
+  public void addPartition(Integer partition, Map<String, Long> statistics)
+  {
+    seen.put(partition, statistics);
+  }
+
+  public Map<String, Long> removePartition(Integer partition)
+  {
+    return seen.remove(partition);
+  }
+
+
+  public Map<Integer, Map<String, Long>> getSeen()
+  {
+    return seen;
+  }
+}
diff --git a/src/main/java/de/juplo/kafka/RecordHandler.java b/src/main/java/de/juplo/kafka/RecordHandler.java
new file mode 100644 (file)
index 0000000..327ac9f
--- /dev/null
@@ -0,0 +1,10 @@
+package de.juplo.kafka;
+
+import org.apache.kafka.clients.consumer.ConsumerRecord;
+
+import java.util.function.Consumer;
+
+
+public interface RecordHandler<K, V> extends Consumer<ConsumerRecord<K,V>>
+{
+}
index 9f3cb81..f8bfe7e 100644 (file)
@@ -4,6 +4,7 @@ consumer:
   client-id: DEV
   topic: test
   auto-offset-reset: earliest
+  commit-interval: 5s
 management:
   endpoint:
     shutdown:
diff --git a/src/test/java/de/juplo/kafka/ApplicationIT.java b/src/test/java/de/juplo/kafka/ApplicationIT.java
new file mode 100644 (file)
index 0000000..2e6ac7d
--- /dev/null
@@ -0,0 +1,41 @@
+package de.juplo.kafka;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.boot.test.web.server.LocalServerPort;
+import org.springframework.kafka.test.context.EmbeddedKafka;
+
+import static de.juplo.kafka.ApplicationTests.TOPIC;
+
+
+@SpringBootTest(
+    webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT,
+    properties = {
+        "consumer.bootstrap-server=${spring.embedded.kafka.brokers}",
+        "consumer.topic=" + TOPIC,
+        "spring.mongodb.embedded.version=4.4.13" })
+@EmbeddedKafka(topics = TOPIC)
+public class ApplicationIT
+{
+  public static final String TOPIC = "FOO";
+
+  @LocalServerPort
+  private int port;
+
+  @Autowired
+  private TestRestTemplate restTemplate;
+
+
+
+  @Test
+  public void   testApplicationStartup()
+  {
+    restTemplate.getForObject(
+        "http://localhost:" + port + "/actuator/health",
+        String.class
+        )
+        .contains("UP");
+  }
+}
diff --git a/src/test/java/de/juplo/kafka/ApplicationTests.java b/src/test/java/de/juplo/kafka/ApplicationTests.java
new file mode 100644 (file)
index 0000000..5b13b7d
--- /dev/null
@@ -0,0 +1,345 @@
+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.context.ConfigDataApplicationContextInitializer;
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.context.annotation.Bean;
+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.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.function.BiConsumer;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+import static de.juplo.kafka.ApplicationTests.PARTITIONS;
+import static de.juplo.kafka.ApplicationTests.TOPIC;
+import static org.assertj.core.api.Assertions.*;
+import static org.awaitility.Awaitility.*;
+
+
+@SpringJUnitConfig(initializers = ConfigDataApplicationContextInitializer.class)
+@TestMethodOrder(MethodOrderer.OrderAnnotation.class)
+@TestPropertySource(
+               properties = {
+                               "consumer.bootstrap-server=${spring.embedded.kafka.brokers}",
+                               "consumer.topic=" + TOPIC,
+                               "consumer.commit-interval=1s" })
+@EmbeddedKafka(topics = TOPIC, partitions = PARTITIONS)
+@EnableAutoConfiguration
+@Slf4j
+class ApplicationTests
+{
+       public static final String TOPIC = "FOO";
+       public static final int PARTITIONS = 10;
+
+
+       StringSerializer stringSerializer = new StringSerializer();
+
+       @Autowired
+       Serializer valueSerializer;
+       @Autowired
+       KafkaProducer<String, Bytes> kafkaProducer;
+       @Autowired
+       KafkaConsumer<String, Long> kafkaConsumer;
+       @Autowired
+       KafkaConsumer<Bytes, Bytes> offsetConsumer;
+       @Autowired
+       ApplicationProperties properties;
+       @Autowired
+       ExecutorService executor;
+       @Autowired
+       KeyCountingRebalanceListener keyCountingRebalanceListener;
+       @Autowired
+       KeyCountingRecordHandler keyCountingRecordHandler;
+
+       EndlessConsumer<String, Long> endlessConsumer;
+       Map<TopicPartition, Long> oldOffsets;
+       Map<TopicPartition, Long> newOffsets;
+       Set<ConsumerRecord<String, Long>> receivedRecords;
+
+
+       /** Tests methods */
+
+       @Test
+       void commitsCurrentOffsetsOnSuccess() throws ExecutionException, InterruptedException
+       {
+               send100Messages((partition, key, counter) ->
+               {
+                       Bytes value = new Bytes(valueSerializer.serialize(TOPIC, counter));
+                       return new ProducerRecord<>(TOPIC, partition, key, value);
+               });
+
+               await("100 records received")
+                               .atMost(Duration.ofSeconds(30))
+                               .pollInterval(Duration.ofSeconds(1))
+                               .until(() -> receivedRecords.size() >= 100);
+
+               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");
+       }
+
+       @Test
+       void commitsOffsetOfErrorForReprocessingOnDeserializationError()
+       {
+               send100Messages((partition, key, counter) ->
+               {
+                       Bytes value = counter == 77
+                                       ? new Bytes(stringSerializer.serialize(TOPIC, "BOOM!"))
+                                       : new Bytes(valueSerializer.serialize(TOPIC, counter));
+                       return new ProducerRecord<>(TOPIC, partition, key, value);
+               });
+
+               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(100);
+
+               assertThatNoException()
+                               .describedAs("Consumer should not be running")
+                               .isThrownBy(() -> endlessConsumer.exitStatus());
+               assertThat(endlessConsumer.exitStatus())
+                               .describedAs("Consumer should have exited abnormally")
+                               .containsInstanceOf(RecordDeserializationException.class);
+       }
+
+
+       /** 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);
+               });
+               // 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<K, V>
+       {
+               public ProducerRecord<String, Bytes> generate(int partition, String key, long counter);
+       }
+
+       void send100Messages(RecordGenerator recordGenerator)
+       {
+               long i = 0;
+
+               for (int partition = 0; partition < 10; partition++)
+               {
+                       for (int key = 0; key < 10; key++)
+                       {
+                               ProducerRecord<String, Bytes> record =
+                                               recordGenerator.generate(partition, Integer.toString(partition*10+key%2), ++i);
+
+                               kafkaProducer.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()
+       {
+               seekToEnd();
+
+               oldOffsets = new HashMap<>();
+               newOffsets = new HashMap<>();
+               receivedRecords = new HashSet<>();
+
+               doForCurrentOffsets((tp, offset) ->
+               {
+                       oldOffsets.put(tp, offset - 1);
+                       newOffsets.put(tp, offset - 1);
+               });
+
+               TestRecordHandler<String, Long> captureOffsetAndExecuteTestHandler =
+                               new TestRecordHandler<String, Long>(keyCountingRecordHandler) {
+                                       @Override
+                                       public void onNewRecord(ConsumerRecord<String, Long> record)
+                                       {
+                                               newOffsets.put(
+                                                               new TopicPartition(record.topic(), record.partition()),
+                                                               record.offset());
+                                               receivedRecords.add(record);
+                                       }
+                               };
+
+               endlessConsumer =
+                               new EndlessConsumer<>(
+                                               executor,
+                                               properties.getClientId(),
+                                               properties.getTopic(),
+                                               kafkaConsumer,
+                                               keyCountingRebalanceListener,
+                                               captureOffsetAndExecuteTestHandler);
+
+               endlessConsumer.start();
+       }
+
+       @AfterEach
+       public void deinit()
+       {
+               try
+               {
+                       endlessConsumer.stop();
+               }
+               catch (Exception e)
+               {
+                       log.info("Exception while stopping the consumer: {}", e.toString());
+               }
+       }
+
+
+       @TestConfiguration
+       @Import(ApplicationConfiguration.class)
+       public static class Configuration
+       {
+               @Bean
+               Serializer<Long> serializer()
+               {
+                       return new LongSerializer();
+               }
+
+               @Bean
+               KafkaProducer<String, Bytes> kafkaProducer(ApplicationProperties properties)
+               {
+                       Properties props = new Properties();
+                       props.put("bootstrap.servers", properties.getBootstrapServer());
+                       props.put("linger.ms", 100);
+                       props.put("key.serializer", StringSerializer.class.getName());
+                       props.put("value.serializer", BytesSerializer.class.getName());
+
+                       return new KafkaProducer<>(props);
+               }
+
+               @Bean
+               KafkaConsumer<Bytes, Bytes> offsetConsumer(ApplicationProperties properties)
+               {
+                       Properties 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());
+
+                       return new KafkaConsumer<>(props);
+               }
+       }
+}
diff --git a/src/test/java/de/juplo/kafka/TestRecordHandler.java b/src/test/java/de/juplo/kafka/TestRecordHandler.java
new file mode 100644 (file)
index 0000000..b4efdd6
--- /dev/null
@@ -0,0 +1,22 @@
+package de.juplo.kafka;
+
+import lombok.RequiredArgsConstructor;
+import org.apache.kafka.clients.consumer.ConsumerRecord;
+
+
+@RequiredArgsConstructor
+public abstract class TestRecordHandler<K, V> implements RecordHandler<K, V>
+{
+  private final RecordHandler<K, V> handler;
+
+
+  public abstract void onNewRecord(ConsumerRecord<K, V> record);
+
+
+  @Override
+  public void accept(ConsumerRecord<K, V> record)
+  {
+    this.onNewRecord(record);
+    handler.accept(record);
+  }
+}