Github user tillrohrmann commented on a diff in the pull request: https://github.com/apache/flink/pull/3278#discussion_r100030377 --- Diff: flink-connectors/flink-connector-kafka-base/src/test/java/org/apache/flink/streaming/connectors/kafka/FlinkKafkaProducerBaseTest.java --- @@ -293,6 +293,61 @@ public void run() { testHarness.close(); } + /** + * This test is meant to assure that testAtLeastOnceProducer is valid by testing that if flushing is disabled, + * the snapshot method does indeed finishes without waiting for pending records; + * we set a timeout because the test will not finish if the logic is broken + */ + @Test(timeout=5000) + public void testDoesNotWaitForPendingRecordsIfFlushingDisabled() throws Throwable { + final OneShotLatch inputLatch = new OneShotLatch(); + + final DummyFlinkKafkaProducer<String> producer = new DummyFlinkKafkaProducer<>( + FakeStandardProducerConfig.get(), null, inputLatch, 100, new AtomicBoolean(false)); + producer.setFlushOnCheckpoint(false); + + final OneInputStreamOperatorTestHarness<String, Object> testHarness = + new OneInputStreamOperatorTestHarness<>(new StreamSink(producer)); + + testHarness.open(); + + List<Callback> pending = producer.getProducerInstance().getPending(); + + for (int i = 0; i < 100; i++) { + testHarness.processElement(new StreamRecord<>("msg-" + i)); + } + + inputLatch.await(); + + // make sure that all callbacks have not been completed + Assert.assertEquals(100, pending.size()); + + // use a separate thread to continuously monitor whether snapshotting has returned + final Tuple1<Throwable> runnableError = new Tuple1<>(null); + Thread snapshotThread = new Thread(new Runnable() { + @Override + public void run() { + try { + testHarness.snapshot(123L, 123L); + } catch (Exception e) { + runnableError.f0 = e; + } + } + }); --- End diff -- Why this additional `Thread`? I think calling directly `testHarness.snapshot` is perfectly fine. Whether you block on this call or on the `Thread.join` does not make a difference.
--- If your project is set up for it, you can reply to this email and have your reply appear on GitHub as well. If your project does not have this feature enabled and wishes so, or if the feature is enabled but not working, please contact infrastructure at infrastruct...@apache.org or file a JIRA ticket with INFRA. ---