[KAFKA-14303] Producer.send without record key and batch.size=0 goes into infinite loop

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.3.0, 3.3.1
• Fix Version/s: 3.4.0, 3.3.2
• Component/s: clients, producer
• Labels: Partitioner bug client producer regresion
• Assignee: Igor Soarez
• Reporter: Igor Soarez
• Created: 14/Oct/22 10:24
• Updated: 27/Dec/22 01:32
• Resolved: 28/Nov/22 19:25

Description

3.3 has broken previous producer behavior.

A call to producer.send(record) with a record without a key and configured with batch.size=0 never returns.

Reproducer:

class ProducerIssueTest extends IntegrationTestHarness {
  override protected def brokerCount = 1
  @Test
  def testProduceWithBatchSizeZeroAndNoRecordKey(): Unit = {
    val topicName = "foo"
    createTopic(topicName)
    val overrides = new Properties
    overrides.put(ProducerConfig.BATCH_SIZE_CONFIG, 0)
    val producer = createProducer(keySerializer = new StringSerializer, valueSerializer = new StringSerializer, overrides)
    val record = new ProducerRecord[String, String](topicName, null, "hello")
    val future = producer.send(record) // goes into infinite loop here
    future.get(10, TimeUnit.SECONDS)
  }
} 

 

Documentation for producer configuration states batch.size=0 as a valid value:

Valid Values: [0,...]

and recommends its use directly:

A small batch size will make batching less common and may reduce throughput (a batch size of zero will disable batching entirely).

Issue Links

• duplicates: KAFKA-14553 RecordAccumulator hangs in infinite NOP loop
• links to: GitHub Pull Request #12752
• links to: GitHub Pull Request #12872