[
https://issues.apache.org/jira/browse/FLINK-9349?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16479387#comment-16479387
]
ASF GitHub Bot commented on FLINK-9349:
---------------------------------------
Github user tzulitai commented on a diff in the pull request:
https://github.com/apache/flink/pull/6040#discussion_r189031464
--- Diff:
flink-connectors/flink-connector-kafka-0.9/src/test/java/org/apache/flink/streaming/connectors/kafka/internal/Flink9349Test.java
---
@@ -0,0 +1,207 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.streaming.connectors.kafka.internal;
+
+import org.apache.flink.api.common.serialization.SimpleStringSchema;
+import org.apache.flink.core.testutils.MultiShotLatch;
+import org.apache.flink.core.testutils.OneShotLatch;
+import org.apache.flink.metrics.groups.UnregisteredMetricsGroup;
+import org.apache.flink.streaming.api.functions.source.SourceFunction;
+import
org.apache.flink.streaming.connectors.kafka.internals.KafkaCommitCallback;
+import
org.apache.flink.streaming.connectors.kafka.internals.KafkaTopicPartition;
+import
org.apache.flink.streaming.connectors.kafka.internals.KafkaTopicPartitionStateSentinel;
+import org.apache.flink.streaming.runtime.tasks.TestProcessingTimeService;
+import
org.apache.flink.streaming.util.serialization.KeyedDeserializationSchema;
+import
org.apache.flink.streaming.util.serialization.KeyedDeserializationSchemaWrapper;
+
+import org.apache.kafka.clients.consumer.ConsumerRecords;
+import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.invocation.InvocationOnMock;
+import org.mockito.stubbing.Answer;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
+
+import static org.junit.Assert.assertFalse;
+import static org.mockito.Mockito.anyLong;
+import static org.powermock.api.mockito.PowerMockito.doAnswer;
+import static org.powermock.api.mockito.PowerMockito.mock;
+import static org.powermock.api.mockito.PowerMockito.when;
+import static org.powermock.api.mockito.PowerMockito.whenNew;
+
+/**
+ * Unit tests for the {@link Flink9349Test}.
+ */
+@RunWith(PowerMockRunner.class)
+@PrepareForTest(KafkaConsumerThread.class)
+public class Flink9349Test {
+ @Test
+ public void testConcurrentPartitionsDiscoveryAndLoopFetching() throws
Exception {
+
+ // test data
+ final KafkaTopicPartition testPartition = new
KafkaTopicPartition("test", 42);
+ final Map<KafkaTopicPartition, Long> testCommitData = new
HashMap<>();
+ testCommitData.put(testPartition, 11L);
+
+ // to synchronize when the consumer is in its blocking method
+ final OneShotLatch sync = new OneShotLatch();
+
+ // ----- the mock consumer with blocking poll calls ----
+ final MultiShotLatch blockerLatch = new MultiShotLatch();
+
+ KafkaConsumer<?, ?> mockConsumer = mock(KafkaConsumer.class);
+ when(mockConsumer.poll(anyLong())).thenAnswer(new
Answer<ConsumerRecords<?, ?>>() {
+
+ @Override
+ public ConsumerRecords<?, ?> answer(InvocationOnMock
invocation) throws InterruptedException {
+ sync.trigger();
+ blockerLatch.await();
+ return ConsumerRecords.empty();
+ }
+ });
+
+ doAnswer(new Answer<Void>() {
+ @Override
+ public Void answer(InvocationOnMock invocation) {
+ blockerLatch.trigger();
+ return null;
+ }
+ }).when(mockConsumer).wakeup();
+
+ // make sure the fetcher creates the mock consumer
+
whenNew(KafkaConsumer.class).withAnyArguments().thenReturn(mockConsumer);
+
+ // ----- create the test fetcher -----
+
+ @SuppressWarnings("unchecked")
+ SourceFunction.SourceContext<String> sourceContext =
mock(SourceFunction.SourceContext.class);
+ Map<KafkaTopicPartition, Long> partitionsWithInitialOffsets =
+ Collections.singletonMap(new
KafkaTopicPartition("test", 42), KafkaTopicPartitionStateSentinel.GROUP_OFFSET);
+ KeyedDeserializationSchema<String> schema = new
KeyedDeserializationSchemaWrapper<>(new SimpleStringSchema());
+
+ final Kafka09Fetcher<String> fetcher = new Kafka09Fetcher<>(
+ sourceContext,
+ partitionsWithInitialOffsets,
+ null, /* periodic watermark extractor */
+ null, /* punctuated watermark extractor */
+ new TestProcessingTimeService(),
+ 10, /* watermark interval */
+ this.getClass().getClassLoader(),
+ "task_name",
+ schema,
+ new Properties(),
+ 0L,
+ new UnregisteredMetricsGroup(),
+ new UnregisteredMetricsGroup(),
+ false);
+
+ // ----- run the fetcher -----
+
+ final AtomicReference<Throwable> error = new
AtomicReference<>();
+ int fetchTasks = 2;
+ final CountDownLatch latch = new CountDownLatch(fetchTasks);
+ ExecutorService service =
Executors.newFixedThreadPool(fetchTasks + 1);
+
+ service.submit(new Thread("fetcher runner ") {
+ @Override
+ public void run() {
+ try {
+ latch.await();
+ fetcher.runFetchLoop();
+ } catch (Throwable t) {
+ error.set(t);
+ }
+ }
+ });
+ for (int i = 0; i < fetchTasks; i++) {
+ service.submit(new Thread("add partitions " + i) {
+
+ @Override
+ public void run() {
+ try {
+ List<KafkaTopicPartition>
newPartitions = new ArrayList<>();
+ for (int i = 0; i < 1000; i++) {
+
newPartitions.add(testPartition);
+ }
+
fetcher.addDiscoveredPartitions(newPartitions);
+ latch.countDown();
+ //latch.await();
+ for (int i = 0; i < 100; i++) {
+
fetcher.addDiscoveredPartitions(newPartitions);
+ Thread.sleep(1L);
+ }
+ } catch (Throwable t) {
+ error.set(t);
+ }
+ }
+ });
+ }
+
+ service.awaitTermination(1L, TimeUnit.SECONDS);
+
+ // wait until the fetcher has reached the method of interest
+ sync.await();
+
+ // ----- trigger the offset commit -----
--- End diff --
I don't think this is required for the scope of interest of this test, is
it?
> KafkaConnector Exception while fetching from multiple kafka topics
> -------------------------------------------------------------------
>
> Key: FLINK-9349
> URL: https://issues.apache.org/jira/browse/FLINK-9349
> Project: Flink
> Issue Type: Bug
> Components: Kafka Connector
> Affects Versions: 1.4.0, 1.5.0
> Reporter: Vishal Santoshi
> Assignee: Sergey Nuyanzin
> Priority: Critical
> Attachments: Flink9349Test.java
>
>
> ./flink-connectors/flink-connector-kafka-0.9/src/main/java/org/apache/flink/streaming/connectors/kafka/internal/Kafka09Fetcher.java
>
> It seems the List subscribedPartitionStates was being modified when
> runFetchLoop iterated the List.
> This can happen if, e.g., FlinkKafkaConsumer runs the following code
> concurrently:
> kafkaFetcher.addDiscoveredPartitions(discoveredPartitions);
>
> {code:java}
> java.util.ConcurrentModificationException
> at
> java.util.LinkedList$ListItr.checkForComodification(LinkedList.java:966)
> at java.util.LinkedList$ListItr.next(LinkedList.java:888)
> at
> org.apache.flink.streaming.connectors.kafka.internal.Kafka09Fetcher.runFetchLoop(Kafka09Fetcher.java:134)
> {code}
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
