import org.apache.kafka.common.TopicPartition;
import org.apache.kafka.common.errors.RecordDeserializationException;
import org.apache.kafka.common.errors.WakeupException;
+import org.springframework.context.ConfigurableApplicationContext;
-import javax.annotation.PreDestroy;
import java.time.Duration;
import java.util.*;
-import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
-import java.util.concurrent.locks.Condition;
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReentrantLock;
@Slf4j
public class EndlessConsumer<K, V> implements Runnable
{
private final ExecutorService executor;
+ private final ConfigurableApplicationContext applicationContext;
private final String id;
private final String topic;
private final Consumer<K, V> consumer;
- private final java.util.function.Consumer<ConsumerRecord<K, V>> handler;
+ private final ConsumerRebalanceListener rebalanceListener;
+ private final RecordHandler<K, V> recordHandler;
- private final Lock lock = new ReentrantLock();
- private final Condition condition = lock.newCondition();
private boolean running = false;
- private Exception exception;
+ private Exception exception = null;
private long consumed = 0;
- private final Map<Integer, Map<String, Long>> seen = new HashMap<>();
- private final Map<Integer, Long> offsets = new HashMap<>();
@Override
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 ->
- {
- Integer partition = tp.partition();
- Long newOffset = consumer.position(tp);
- Long oldOffset = offsets.remove(partition);
- log.info(
- "{} - removing partition: {}, consumed {} records (offset {} -> {})",
- id,
- partition,
- newOffset - oldOffset,
- oldOffset,
- newOffset);
- Map<String, Long> removed = seen.remove(partition);
- for (String key : removed.keySet())
- {
- log.info(
- "{} - Seen {} messages for partition={}|key={}",
- id,
- removed.get(key),
- partition,
- key);
- }
- });
- }
-
- @Override
- public void onPartitionsAssigned(Collection<TopicPartition> partitions)
- {
- partitions.forEach(tp ->
- {
- Integer partition = tp.partition();
- Long offset = consumer.position(tp);
- log.info("{} - adding partition: {}, offset={}", id, partition, offset);
- offsets.put(partition, offset);
- seen.put(partition, new HashMap<>());
- });
- }
- });
+ consumer.subscribe(Arrays.asList(topic), rebalanceListener);
while (true)
{
record.value()
);
- handler.accept(record);
+ recordHandler.accept(record);
consumed++;
-
- 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);
}
}
}
catch(WakeupException e)
{
log.info("{} - RIIING! Request to stop consumption - commiting current offsets!", id);
- consumer.commitSync();
- shutdown();
}
catch(RecordDeserializationException e)
{
tp,
offset,
e.getCause().toString());
-
- consumer.commitSync();
- shutdown(e);
+ this.exception = e;
}
catch(Exception e)
{
log.error("{} - Unexpected error: {}", id, e.toString(), e);
- shutdown(e);
+ this.exception = e;
+ log.info("{} - Unsubscribing...", id);
+ consumer.unsubscribe();
}
finally
{
+ running = false;
+ log.info("{} - Closing the consumer...", id);
+ consumer.close();
+ log.info("{} - Shutting down the app...", id);
+ applicationContext.close();
log.info("{} - Consumer-Thread exiting", id);
}
}
- 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, Long>> getSeen()
- {
- return seen;
- }
-
public void start()
{
- lock.lock();
- try
- {
- if (running)
- throw new IllegalStateException("Consumer instance " + id + " is already running!");
-
- 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
- {
- lock.lock();
- try
- {
- if (!running)
- throw new IllegalStateException("Consumer instance " + id + " is not running!");
+ if (running)
+ throw new IllegalStateException("Consumer instance " + id + " is already running!");
- log.info("{} - Stopping", id);
- consumer.wakeup();
- condition.await();
- log.info("{} - Stopped - consumed {} messages so far", id, consumed);
- }
- finally
- {
- lock.unlock();
- }
+ log.info("{} - Starting - consumed {} messages before", id, consumed);
+ running = true;
+ executor.submit(this);
}
- @PreDestroy
- public void destroy() throws ExecutionException, InterruptedException
+ public void stop()
{
- 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);
- }
+ consumer.wakeup();
}
-
public boolean running()
{
- lock.lock();
- try
- {
- return running;
- }
- finally
- {
- lock.unlock();
- }
+ return running;
}
public Optional<Exception> exitStatus()
{
- lock.lock();
- try
- {
- if (running)
- throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
+ if (running)
+ throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
- return Optional.ofNullable(exception);
- }
- finally
- {
- lock.unlock();
- }
+ return Optional.ofNullable(exception);
}
}
projects / demos / kafka / training / blobdiff