private void commitOffsetsForAckedTuples() {
// Find offsets that are ready to be committed for every topic partition
final Map<TopicPartition, OffsetAndMetadata> nextCommitOffsets = new HashMap<>();
for (Map.Entry<TopicPartition, OffsetEntry> tpOffset : acked.entrySet()) {
final OffsetAndMetadata nextCommitOffset = tpOffset.getValue().findNextCommitOffset();
if (nextCommitOffset != null) {
nextCommitOffsets.put(tpOffset.getKey(), nextCommitOffset);
}
}
// Commit offsets that are ready to be committed for every topic partition
if (!nextCommitOffsets.isEmpty()) {
kafkaConsumer.commitSync(nextCommitOffsets);
LOG.debug("Offsets successfully committed to Kafka [{}]", nextCommitOffsets);
// Instead of iterating again, it would be possible to commit and update the state for each
// TopicPartition
// in the prior loop, but the multiple network calls should be more expensive than iterating
// twice over a small loop
for (Map.Entry<TopicPartition, OffsetEntry> tpOffset : acked.entrySet()) {
final OffsetEntry offsetEntry = tpOffset.getValue();
offsetEntry.commit(nextCommitOffsets.get(tpOffset.getKey()));
}
} else {
LOG.trace("No offsets to commit. {}", this);
}
}
private static void processRecords(KafkaConsumer<String, String> consumer)
throws InterruptedException {
while (true) {
ConsumerRecords<String, String> records = consumer.poll(100);
long lastOffset = 0;
for (ConsumerRecord<String, String> record : records) {
System.out.printf(
"\n\roffset = %d, key = %s, value = %s", record.offset(), record.key(), record.value());
lastOffset = record.offset();
}
System.out.println("lastOffset read: " + lastOffset);
process();
// Below call is important to control the offset commit. Do this call after you
// finish processing the business process to get the at least once guarantee.
consumer.commitSync();
}
}