Kafka 0.9 How to re-consume message when manually committing offset with a KafkaConsumer

Question

I am writing a consumer that manually commits the offset once a series of records are commited to Mongo.
In the case of a Mongo error or any other error an attempt is made to persit the record to an error processing collection for replay at a later date. If Mongo is down then I want the consumer to stop processing for a period of time before trying to read the records from the uncommited offset from Kakfa.
The below sample works but I would like to know what the best practice for this scenario is?

while (true) {
    boolean commit = false;
    try {
        ConsumerRecords<K, V> records = consumer.poll(consumerTimeout);
        kafkaMessageProcessor.processRecords(records);
        commit = true;
    }
    catch (Exception e) {
        logger.error("Unable to consume closing consumer and restarting", e);
        try {
           consumer.close();
        }
        catch (Exception consumerCloseError) {
            logger.error("Unable to close consumer", consumerCloseError);
        }
        logger.error(String.format("Attempting recovery in  [%d] milliseconds.", recoveryInterval), e);
        Thread.sleep(recoveryInterval);
        consumer = createConsumer(properties);
    }
    if (commit) {
        consumer.commitSync();
    }

}

private KafkaConsumer<K, V> createConsumer(Properties properties) {
    KafkaConsumer<K, V> consumer = new KafkaConsumer<K, V>(properties);
    consumer.subscribe(topics);
    return consumer;
}

If I don't recreate the consumer I get the following error.

o.a.k.c.c.internals.AbstractCoordinator  : Marking the coordinator 2147483647 dead.
o.a.k.c.c.internals.ConsumerCoordinator  : Error ILLEGAL_GENERATION occurred while committing offsets for group test.consumer

Answer 1

Here is my code using client version 0.10.0 .

Seem is ok for you demand.

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;

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.OffsetAndMetadata;
import org.apache.kafka.clients.consumer.OffsetCommitCallback;
import org.apache.kafka.common.TopicPartition;
import org.apache.kafka.common.serialization.StringDeserializer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class MessageProcesser implements Runnable {

    private static Logger logger = LoggerFactory.getLogger(MessageProcesser.class);

    private final ExecutorService pool = Executors.newFixedThreadPool(4);

    private final KafkaConsumer<String, String> consumer;

    private final String topic;

    private final AtomicBoolean closed = new AtomicBoolean(false);

    public MessageProcesser(String groupId, String topic, String kafkaServer) {
        this.topic = topic;
        Properties props = new Properties();
        props.put("bootstrap.servers", kafkaServer);
        props.put("group.id", groupId);
        props.put("key.deserializer", StringDeserializer.class.getName());
        props.put("value.deserializer", StringDeserializer.class.getName());
        props.put("enable.auto.commit", "false");
        this.consumer = new KafkaConsumer<>(props);
    }

    @Override
    public void run() {
        try {

            consumer.subscribe(Collections.singleton(topic));

            while (true) {
                if (closed.get()) {
                    consumer.close();
                }

                ConsumerRecords<String, String> records = consumer.poll(1000 * 60); 
                for (ConsumerRecord<String, String> record : records) {

                    String value = record.value();
                    if (null == value) {
                        continue;
                    }

                    boolean processResult = false;
                    try {
                        Future<Object> f = pool.submit(new ProcessCommand(value));
                        processResult = (boolean) f.get(100, TimeUnit.MILLISECONDS);
                    } catch (Exception e) {
                        logger.error(e.getMessage(), e);
                    }

                    if (!processResult) {
                        //here if process fail, seek to current offset
                        consumer.seek(new TopicPartition(record.topic(), record.partition()), record.offset());
                    } else {
                        this.commitAsyncOffset(record);
                    }
                }
            }
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
            if (!closed.get()) {
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e1) {
                    // ignore
                }
            }
        }
    }

    public void shutdown() {
        closed.set(true);
    }

    public void commitAsyncOffset(ConsumerRecord<String, String> record) {
        Map<TopicPartition, OffsetAndMetadata> offsets = new HashMap<>();
        offsets.put(new TopicPartition(record.topic(), record.partition()), new OffsetAndMetadata(record.offset() + 1));

        consumer.commitAsync(offsets, new OffsetCommitCallback() {
            @Override
            public void onComplete(Map<TopicPartition, OffsetAndMetadata> offsets, Exception e) {
                if (e != null) {
                    logger.error("kafka offset commit fail. {} {}", offsets, PushUtil.getStackString(e.getStackTrace()));
                }
            }
        });
    }
}