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.Clock;
import java.time.Duration;
+import java.time.Instant;
import java.util.*;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Future;
-import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.regex.Pattern;
@Slf4j
-public class EndlessConsumer implements Runnable
+@RequiredArgsConstructor
+public class EndlessConsumer implements ConsumerRebalanceListener, Runnable
{
+ final static Pattern PATTERN = Pattern.compile("\\W+");
+
+
private final ExecutorService executor;
private final PartitionStatisticsRepository repository;
- private final String bootstrapServer;
- private final String groupId;
private final String id;
private final String topic;
- private final String autoOffsetReset;
+ private final Clock clock;
+ private final Duration commitInterval;
+ private final Consumer<String, String> consumer;
- private AtomicBoolean running = new AtomicBoolean();
+ 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 Future<?> future = null;
- private final Map<TopicPartition, PartitionStatistics> seen = new HashMap<>();
+ private final Map<Integer, Map<String, Map<String, Long>>> seen = new HashMap<>();
- public EndlessConsumer(
- ExecutorService executor,
- PartitionStatisticsRepository repository,
- String bootstrapServer,
- String groupId,
- String clientId,
- String topic,
- String autoOffsetReset)
+ @Override
+ public void onPartitionsRevoked(Collection<TopicPartition> partitions)
{
- this.executor = executor;
- this.repository = repository;
- this.bootstrapServer = bootstrapServer;
- this.groupId = groupId;
- this.id = clientId;
- this.topic = topic;
- this.autoOffsetReset = autoOffsetReset;
+ partitions.forEach(tp ->
+ {
+ Integer partition = tp.partition();
+ Long newOffset = consumer.position(tp);
+ log.info(
+ "{} - removing partition: {}, offset of next message {})",
+ id,
+ partition,
+ newOffset);
+ Map<String, Map<String, Long>> removed = seen.remove(partition);
+ repository.save(new StatisticsDocument(partition, removed, consumer.position(tp)));
+ });
}
@Override
- public void run()
+ public void onPartitionsAssigned(Collection<TopicPartition> partitions)
{
- try
+ partitions.forEach(tp ->
{
- Properties props = new Properties();
- props.put("bootstrap.servers", bootstrapServer);
- props.put("group.id", groupId);
- props.put("client.id", id);
- props.put("enable.auto.commit", false);
- 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());
+ Integer partition = tp.partition();
+ Long offset = consumer.position(tp);
+ log.info("{} - adding partition: {}, offset={}", id, partition, offset);
+ StatisticsDocument document =
+ repository
+ .findById(Integer.toString(partition))
+ .orElse(new StatisticsDocument(partition));
+ if (document.offset >= 0)
+ {
+ // Only seek, if a stored offset was found
+ // Otherwise: Use initial offset, generated by Kafka
+ consumer.seek(tp, document.offset);
+ }
+ seen.put(partition, document.statistics);
+ });
+ }
- this.consumer = new KafkaConsumer<>(props);
+ @Override
+ public void run()
+ {
+ try
+ {
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);
- PartitionStatistics removed = seen.remove(tp);
- for (KeyCounter counter : removed.getStatistics())
- {
- log.info(
- "{} - Seen {} messages for partition={}|key={}",
- id,
- counter.getResult(),
- removed.getPartition(),
- counter.getKey());
- }
- repository.save(new StatisticsDocument(removed, consumer.position(tp)));
- });
- }
+ consumer.subscribe(Arrays.asList(topic), this);
- @Override
- public void onPartitionsAssigned(Collection<TopicPartition> partitions)
- {
- partitions.forEach(tp ->
- {
- log.info("{} - adding partition: {}", id, tp);
- StatisticsDocument document =
- repository
- .findById(tp.toString())
- .orElse(new StatisticsDocument(tp));
- consumer.seek(tp, document.offset);
- seen.put(tp, new PartitionStatistics(document));
- });
- }
- });
+ Instant lastCommit = clock.instant();
while (true)
{
log.info("{} - Received {} messages", id, records.count());
for (ConsumerRecord<String, String> record : records)
{
- consumed++;
log.info(
"{} - {}: {}/{} - {}={}",
id,
record.value()
);
- TopicPartition partition = new TopicPartition(record.topic(), record.partition());
- String key = record.key() == null ? "NULL" : record.key();
- seen.get(partition).increment(key);
+ consumed++;
+
+ Integer partition = record.partition();
+ String user = record.key();
+ Map<String, Map<String, Long>> users = seen.get(partition);
+
+ Map<String, Long> words = users.get(user);
+ if (words == null)
+ {
+ words = new HashMap<>();
+ users.put(user, words);
+ }
+
+ for (String word : PATTERN.split(record.value()))
+ {
+ Long num = words.get(word);
+ if (num == null)
+ {
+ num = 1l;
+ }
+ else
+ {
+ num++;
+ }
+ words.put(word, num);
+ }
}
- seen.forEach((tp, statistics) -> repository.save(new StatisticsDocument(statistics, consumer.position(tp))));
+ if (lastCommit.plus(commitInterval).isBefore(clock.instant()))
+ {
+ log.debug("Storing data and offsets, last commit: {}", lastCommit);
+ seen.forEach((partiton, statistics) -> repository.save(
+ new StatisticsDocument(
+ partiton,
+ statistics,
+ consumer.position(new TopicPartition(topic, partiton)))));
+ lastCommit = clock.instant();
+ }
}
}
catch(WakeupException e)
{
- log.info("{} - RIIING!", id);
+ log.info("{} - RIIING! Request to stop consumption - commiting current offsets!", id);
+ 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());
+
+ shutdown(e);
}
catch(Exception e)
{
log.error("{} - Unexpected error: {}", id, e.toString(), e);
- running.set(false); // Mark the instance as not running
+ shutdown(e);
}
finally
{
- log.info("{} - Closing the KafkaConsumer", id);
- consumer.close();
log.info("{} - Consumer-Thread exiting", id);
}
}
- public Map<TopicPartition, PartitionStatistics> getSeen()
+ private void shutdown()
+ {
+ shutdown(null);
+ }
+
+ private void shutdown(Exception e)
+ {
+ lock.lock();
+ try
+ {
+ 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
+ {
+ lock.unlock();
+ }
+ }
+
+ public Map<Integer, Map<String, Map<String, Long>>> getSeen()
{
return seen;
}
- public synchronized void start()
+ public void start()
{
- boolean stateChanged = running.compareAndSet(false, true);
- if (!stateChanged)
- throw new RuntimeException("Consumer instance " + id + " is already running!");
+ lock.lock();
+ try
+ {
+ if (running)
+ throw new IllegalStateException("Consumer instance " + id + " is already running!");
- log.info("{} - Starting - consumed {} messages before", id, consumed);
- future = executor.submit(this);
+ log.info("{} - Starting - consumed {} messages before", id, consumed);
+ running = true;
+ exception = null;
+ executor.submit(this);
+ }
+ finally
+ {
+ lock.unlock();
+ }
}
- public synchronized void stop() throws ExecutionException, InterruptedException
+ public synchronized void stop() throws InterruptedException
{
- boolean stateChanged = running.compareAndSet(true, false);
- if (!stateChanged)
- throw new RuntimeException("Consumer instance " + id + " is not running!");
-
- log.info("{} - Stopping", id);
- consumer.wakeup();
- future.get();
- log.info("{} - Stopped - consumed {} messages so far", id, consumed);
+ lock.lock();
+ try
+ {
+ if (!running)
+ throw new IllegalStateException("Consumer instance " + id + " is not running!");
+
+ log.info("{} - Stopping", id);
+ consumer.wakeup();
+ condition.await();
+ log.info("{} - Stopped - consumed {} messages so far", id, consumed);
+ }
+ finally
+ {
+ lock.unlock();
+ }
}
@PreDestroy
public void destroy() throws ExecutionException, InterruptedException
{
log.info("{} - Destroy!", id);
+ log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
+ }
+
+ public boolean running()
+ {
+ lock.lock();
try
{
- stop();
+ return running;
+ }
+ finally
+ {
+ lock.unlock();
}
- catch (IllegalStateException e)
+ }
+
+ public Optional<Exception> exitStatus()
+ {
+ lock.lock();
+ try
{
- log.info("{} - Was already stopped", id);
+ if (running)
+ throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
+
+ return Optional.ofNullable(exception);
}
finally
{
- log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
+ lock.unlock();
}
}
}
projects / demos / kafka / training / blobdiff