How to manually control the offset commit with camel-kafka?

Question

I\'m using the camel kafka component and I\'m unclear what is happening under the hood with committing the offsets. As can be seen below, I\'m aggregating records and I thin

Answer 1

You can control manual offset commit even in multi threaded route (using aggregator for exemple) by using offset repository (Camel Documentation)

@Override
public void configure() throws Exception {
      // The route
      from(kafkaEndpoint())
            .routeId(ROUTE_ID)
            // Some processors...
            // Commit kafka offset
            .process(MyRoute::commitKafka)
            // Continue or not...
            .to(someEndpoint());
}

private String kafkaEndpoint() {
    return new StringBuilder("kafka:")
            .append(kafkaConfiguration.getTopicName())
            .append("?brokers=")
            .append(kafkaConfiguration.getBootstrapServers())
            .append("&groupId=")
            .append(kafkaConfiguration.getGroupId())
            .append("&clientId=")
            .append(kafkaConfiguration.getClientId())
            .append("&autoCommitEnable=")
            .append(false)
            .append("&allowManualCommit=")
            .append(true)
            .append("&autoOffsetReset=")
            .append("earliest")
            .append("&offsetRepository=")
            .append("#fileStore")
            .toString();

}

@Bean(name = "fileStore", initMethod = "start", destroyMethod = "stop")
private FileStateRepository fileStore() {
    FileStateRepository fileStateRepository = 
    FileStateRepository.fileStateRepository(new File(kafkaConfiguration.getOffsetFilePath()));
    fileStateRepository.setMaxFileStoreSize(10485760); // 10MB max

    return fileStateRepository;
}

private static void commitKafka(Exchange exchange) {
    KafkaManualCommit manual = exchange.getIn().getHeader(KafkaConstants.MANUAL_COMMIT, KafkaManualCommit.class);
    manual.commitSync();
}