import org.apache.kafka.clients.consumer.Consumer;
import org.apache.kafka.common.TopicPartition;
+import java.time.Clock;
+import java.time.Duration;
+import java.time.Instant;
import java.util.*;
@RequiredArgsConstructor
@Slf4j
-public class ApplicationRebalanceListener implements CommittingConsumerRebalanceListener
+public class ApplicationRebalanceListener implements RebalanceListener
{
private final ApplicationRecordHandler recordHandler;
private final AdderResults adderResults;
private final StateRepository stateRepository;
private final String id;
+ private final String topic;
+ private final Clock clock;
+ private final Duration commitInterval;
private final Consumer consumer;
private final Set<Integer> partitions = new HashSet<>();
+ private Instant lastCommit = Instant.EPOCH;
private boolean commitsEnabled = true;
@Override
stateRepository
.findById(Integer.toString(partition))
.orElse(new StateDocument(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);
+ log.info(
+ "{} - Seeking to offset {} for partition {}",
+ id,
+ document.offset,
+ partition);
+ }
recordHandler.addPartition(partition, document.state);
for (String user : document.state.keySet())
{
@Override
public void onPartitionsRevoked(Collection<TopicPartition> partitions)
{
- if (commitsEnabled)
- {
- log.info("{} - Commiting offsets for all previously assigned partitions", id);
- try
- {
- consumer.commitSync();
- }
- catch (Exception e)
- {
- log.warn("{} - Could not commit offsets in onPartitionsRevoked():", id, e);
- }
- }
-
partitions.forEach(tp ->
{
Integer partition = tp.partition();
log.info("{} - removing partition: {}", id, partition);
this.partitions.remove(partition);
- Map<String, AdderResult> state = recordHandler.removePartition(partition);
- for (String user : state.keySet())
+ if (commitsEnabled)
{
+ Map<String, AdderResult> state = recordHandler.removePartition(partition);
+ Long offset = consumer.position(tp);
log.info(
- "{} - Saved state for partition={}|user={}: {}",
+ "{} - offset of next unseen message for partition {} is {}",
id,
partition,
- user,
- state.get(user));
+ offset);
+ for (String user : state.keySet())
+ {
+ log.info(
+ "{} - Saved state for partition={}|user={}: {}",
+ id,
+ partition,
+ user,
+ state.get(user));
+ }
+ Map<String, List<AdderResult>> results = adderResults.removePartition(partition);
+ stateRepository.save(new StateDocument(partition, state, results, offset));
+ }
+ else
+ {
+ log.info("{} - Offset commits are disabled! Last commit: {}", id, lastCommit);
}
- Map<String, List<AdderResult>> results = adderResults.removePartition(partition);
- stateRepository.save(new StateDocument(partition, state, results));
});
}
+
+ @Override
+ public void beforeNextPoll()
+ {
+ if (!commitsEnabled)
+ {
+ log.info("{} - Offset commits are disabled! Last commit: {}", id, lastCommit);
+ return;
+ }
+
+ if (lastCommit.plus(commitInterval).isBefore(clock.instant()))
+ {
+ partitions
+ .stream()
+ .forEach(partition ->
+ {
+ log.info("{} - persisting state & offset for partition: {}", id, partition);
+ Map<String, AdderResult> state = recordHandler.getState(partition).getState();
+ Long offset = consumer.position(new TopicPartition(topic, partition));
+ log.info(
+ "{} - offset of next unseen message for partition {} is {}",
+ id,
+ partition,
+ offset);
+ for (String user : state.keySet())
+ {
+ log.info(
+ "{} - Saved state for partition={}|user={}: {}",
+ id,
+ partition,
+ user,
+ state.get(user));
+ }
+ Map<String, List<AdderResult>> results = adderResults.getState(partition);
+ stateRepository.save(new StateDocument(partition, state, results, offset));
+ });
+
+ lastCommit = clock.instant();
+ }
+ }
+
@Override
public void enableCommits()
{