Tomasz Nguyen created KAFKA-12375:
-------------------------------------
Summary: ReplaceStreamThread creates a new consumer with the same
name as the one it's replacing
Key: KAFKA-12375
URL: https://issues.apache.org/jira/browse/KAFKA-12375
Project: Kafka
Issue Type: Bug
Components: streams
Affects Versions: 2.8.0
Reporter: Tomasz Nguyen
Fix For: 2.8.0
I was debugging the kafka-streams soak cluster and noticed that replacing a
stream thread was causing the streams application to fail. I have managed to
find the following stacktrace:
{code:java}
javax.management.InstanceAlreadyExistsException:
kafka.consumer:type=app-info,id=i-0cdac8830ee1b8f01-StreamThread-1-restore-consumer
at com.sun.jmx.mbeanserver.Repository.addMBean(Repository.java:437) at
com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerWithRepository(DefaultMBeanServerInterceptor.java:1898)
at
com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:966)
at
com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:900)
at
com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:324)
at
com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:522)
at
org.apache.kafka.common.utils.AppInfoParser.registerAppInfo(AppInfoParser.java:64)
at
org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:815)
at
org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:666)
at
org.apache.kafka.streams.processor.internals.DefaultKafkaClientSupplier.getRestoreConsumer(DefaultKafkaClientSupplier.java:56)
at
org.apache.kafka.streams.processor.internals.StreamThread.create(StreamThread.java:338)
at
org.apache.kafka.streams.KafkaStreams.createAndAddStreamThread(KafkaStreams.java:896)
at
org.apache.kafka.streams.KafkaStreams.addStreamThread(KafkaStreams.java:977) at
org.apache.kafka.streams.KafkaStreams.replaceStreamThread(KafkaStreams.java:467)
at
org.apache.kafka.streams.KafkaStreams.handleStreamsUncaughtException(KafkaStreams.java:487)
at
org.apache.kafka.streams.KafkaStreams.lambda$setUncaughtExceptionHandler$1(KafkaStreams.java:427)
at
org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:607)
at
org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:555)
{code}
followed by:
{code:java}
Exception in thread "i-0e4d869ffd67ec825-StreamThread-1"
java.util.ConcurrentModificationException: KafkaConsumer is not safe for
multi-threaded access at
org.apache.kafka.clients.consumer.KafkaConsumer.acquire(KafkaConsumer.java:2446)
at
org.apache.kafka.clients.consumer.KafkaConsumer.acquireAndEnsureOpen(KafkaConsumer.java:2430)
at
org.apache.kafka.clients.consumer.KafkaConsumer.enforceRebalance(KafkaConsumer.java:2261)
at
org.apache.kafka.streams.processor.internals.StreamThread.sendShutdownRequest(StreamThread.java:666)
at
org.apache.kafka.streams.KafkaStreams.lambda$handleStreamsUncaughtException$4(KafkaStreams.java:508)
at
org.apache.kafka.streams.KafkaStreams.processStreamThread(KafkaStreams.java:1579)
at
org.apache.kafka.streams.KafkaStreams.handleStreamsUncaughtException(KafkaStreams.java:508)
at
org.apache.kafka.streams.KafkaStreams.lambda$setUncaughtExceptionHandler$1(KafkaStreams.java:427)
at
org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:607)
at
org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:555)
{code}
My understanding so far is that we re-use the consumer name across thread
generations which can hit a few flavours of a race condition. My suggestion
would be to add the generation-id to the consumer name.
This could be done by adding a thread generation id here
https://github.com/apache/kafka/blob/b35ca4349dabb199411cb6bc4c80ef89f19d9328/streams/src/main/java/org/apache/kafka/streams/processor/internals/ClientUtils.java#L66
or by adding an overload here:
https://github.com/apache/kafka/blob/b35ca4349dabb199411cb6bc4c80ef89f19d9328/streams/src/main/java/org/apache/kafka/streams/processor/internals/StreamThread.java#L390
{code:java}
// Some comments here
final Map<String, Object> consumerConfigs =
config.getMainConsumerConfigs(applicationId, getConsumerClientId(threadId),
threadIdx, generationId);
{code}
I have not yet checked if there are any implications to either of these
solutions
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