package de.juplo.kafka;
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.common.TopicPartition;
import org.apache.kafka.common.errors.WakeupException;
import org.apache.kafka.common.serialization.StringDeserializer;
import javax.annotation.PreDestroy;
import java.time.Duration;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Properties;
+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;
@Slf4j
public class EndlessConsumer implements Runnable
{
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 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 Map<Integer, Map<String, Integer>> seen;
+
+ private final Map<Integer, Map<String, Integer>> seen = new HashMap<>();
public EndlessConsumer(
ExecutorService executor,
+ PartitionStatisticsRepository repository,
String bootstrapServer,
String groupId,
String clientId,
String autoOffsetReset)
{
this.executor = executor;
+ this.repository = repository;
this.bootstrapServer = bootstrapServer;
this.groupId = groupId;
this.id = clientId;
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());
this.consumer = new KafkaConsumer<>(props);
log.info("{} - Subscribing to topic {}", id, topic);
- consumer.subscribe(Arrays.asList(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);
+ }
+ repository.save(new StatisticsDocument(tp.partition(), removed, consumer.position(tp)));
+ });
+ }
- seen = new HashMap<>();
+ @Override
+ public void onPartitionsAssigned(Collection<TopicPartition> partitions)
+ {
+ partitions.forEach(tp ->
+ {
+ log.info("{} - adding partition: {}", id, tp);
+ StatisticsDocument document =
+ repository
+ .findById(Integer.toString(tp.partition()))
+ .orElse(new StatisticsDocument(tp.partition()));
+ consumer.seek(tp, document.offset);
+ seen.put(tp.partition(), document.statistics);
+ });
+ }
+ });
while (true)
{
);
Integer partition = record.partition();
- String key = record.key();
-
- if (!seen.containsKey(partition))
- seen.put(partition, new HashMap<>());
-
+ String key = record.key() == null ? "NULL" : record.key();
Map<String, Integer> byKey = seen.get(partition);
if (!byKey.containsKey(key))
seenByKey++;
byKey.put(key, seenByKey);
}
+
+ seen.forEach((partiton, statistics) -> repository.save(
+ new StatisticsDocument(
+ partiton,
+ statistics,
+ consumer.position(new TopicPartition(topic, partiton)))));
}
}
catch(WakeupException e)
{
log.info("{} - RIIING!", id);
+ shutdown();
}
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);
+ }
+ }
- for (Integer partition : seen.keySet())
- {
- Map<String, Integer> byKey = seen.get(partition);
- for (String key : byKey.keySet())
- {
- log.info(
- "{} - Seen {} messages for partition={}|key={}",
- id,
- byKey.get(key),
- partition,
- key);
- }
- }
- seen = null;
+ private void shutdown()
+ {
+ shutdown(null);
+ }
- log.info("{} - Consumer-Thread exiting", id);
+ private void shutdown(Exception e)
+ {
+ lock.lock();
+ try
+ {
+ running = false;
+ exception = e;
+ condition.signal();
+ }
+ finally
+ {
+ lock.unlock();
}
}
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
{
- 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
{
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);
}
}
+
+ public boolean running()
+ {
+ lock.lock();
+ try
+ {
+ return running;
+ }
+ finally
+ {
+ lock.unlock();
+ }
+ }
+
+ public Optional<Exception> exitStatus()
+ {
+ lock.lock();
+ try
+ {
+ if (running)
+ throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
+
+ return Optional.ofNullable(exception);
+ }
+ finally
+ {
+ lock.unlock();
+ }
+ }
}
projects / demos / kafka / training / blobdiff