C0urante commented on code in PR #11778: URL: https://github.com/apache/kafka/pull/11778#discussion_r890724606
########## connect/runtime/src/main/java/org/apache/kafka/connect/storage/KafkaConfigBackingStore.java: ########## @@ -309,16 +342,71 @@ public void start() { @Override public void stop() { log.info("Closing KafkaConfigBackingStore"); - try { - configLog.stop(); - } finally { - if (ownTopicAdmin != null) { - ownTopicAdmin.close(); - } + + if (fencableProducer != null) { + Utils.closeQuietly(() -> fencableProducer.close(Duration.ZERO), "fencable producer for config topic"); } + Utils.closeQuietly(ownTopicAdmin, "admin for config topic"); + Utils.closeQuietly(configLog::stop, "KafkaBasedLog for config topic"); + log.info("Closed KafkaConfigBackingStore"); } + @Override + public void claimWritePrivileges() { + if (usesFencableWriter && fencableProducer == null) { + try { + fencableProducer = createFencableProducer(); + fencableProducer.initTransactions(); + } catch (Exception e) { + if (fencableProducer != null) { + Utils.closeQuietly(() -> fencableProducer.close(Duration.ZERO), "fencable producer for config topic"); + fencableProducer = null; + } + throw new ConnectException("Failed to create and initialize fencable producer for config topic", e); + } + } + } + + private Map<String, Object> baseProducerProps(WorkerConfig workerConfig) { + Map<String, Object> producerProps = new HashMap<>(workerConfig.originals()); + String kafkaClusterId = ConnectUtils.lookupKafkaClusterId(workerConfig); + producerProps.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName()); + producerProps.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, ByteArraySerializer.class.getName()); + producerProps.put(ProducerConfig.DELIVERY_TIMEOUT_MS_CONFIG, Integer.MAX_VALUE); + ConnectUtils.addMetricsContextProperties(producerProps, workerConfig, kafkaClusterId); + return producerProps; + } + + // Visible for testing + Map<String, Object> fencableProducerProps(DistributedConfig workerConfig) { + Map<String, Object> result = new HashMap<>(baseProducerProps(workerConfig)); + + // Always require producer acks to all to ensure durable writes + result.put(ProducerConfig.ACKS_CONFIG, "all"); + // Don't allow more than one in-flight request to prevent reordering on retry Review Comment: 🤦 ########## connect/runtime/src/main/java/org/apache/kafka/connect/storage/KafkaConfigBackingStore.java: ########## @@ -547,6 +663,27 @@ KafkaBasedLog<String, byte[]> setupAndCreateKafkaBasedLog(String topic, final Wo return createKafkaBasedLog(topic, producerProps, consumerProps, new ConsumeCallback(), topicDescription, adminSupplier); } + private void maybeSendFencably(String key, byte[] value) { + if (!usesFencableWriter) { + configLog.send(key, value); + return; + } + + if (fencableProducer == null) { + throw new IllegalStateException("Cannot produce to config topic without claiming write privileges first"); + } + + try { + fencableProducer.beginTransaction(); + fencableProducer.send(new ProducerRecord<>(topic, key, value)); + fencableProducer.commitTransaction(); + } catch (ProducerFencedException e) { + log.warn("Failed to write to config topic as producer was fenced out", e); + fencableProducer = null; Review Comment: Yes, we should close it in this case. I originally wanted to be more conservative about other cases, but after thinking it over, I'd rather not risk getting into a bad state with a transactional producer that can't be fixed and requires a new one. Given the expected low frequency of writes to the config topic, it's probably fine to also close the producer and then construct a new one in `claimWritePrivileges` in this case. Good catch! -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org