RivenSun created KAFKA-13663:
--------------------------------
Summary: IllegalMonitorStateException in
ProducerMetadata.awaitUpdate
Key: KAFKA-13663
URL: https://issues.apache.org/jira/browse/KAFKA-13663
Project: Kafka
Issue Type: Bug
Components: clients
Affects Versions: 3.0.0
Reporter: RivenSun
Assignee: Guozhang Wang
Since our service kafka-clients was upgraded to {*}2.8.1{*}, sometimes the
producer will throw an exception when sending a message, and once this
exception occurs, it will continue and will not recover by itself.
{code:java}
java.lang.IllegalMonitorStateException: current thread is not owner
at java.base/java.lang.Object.wait(Native Method)
at
org.apache.kafka.common.utils.SystemTime.waitObject(SystemTime.java:55)
at
org.apache.kafka.clients.producer.internals.ProducerMetadata.awaitUpdate(ProducerMetadata.java:119)
at
org.apache.kafka.clients.producer.KafkaProducer.waitOnMetadata(KafkaProducer.java:1047)
at
org.apache.kafka.clients.producer.KafkaProducer.doSend(KafkaProducer.java:906)
at
org.apache.kafka.clients.producer.KafkaProducer.send(KafkaProducer.java:885)
{code}
The version of kafka-clients used before is {*}2.2.2{*}, and this exception has
never occurred
Comparing the changes in the kafkaClient source code, I found that there is a
change, it is very likely that this is a *regression bug.*
In version 2.2.2, the `Metadata#awaitUpdate` method is called in
`KafkaProducer#waitOnMetadata`
But since version {*}2.3.0{*}, `ProducerMetadata#awaitUpdate` is called in
`KafkaProducer#waitOnMetadata`
The most crucial point is:
`Object#wait(long timeoutMillis)` method,
In the `Metadata#awaitUpdate` method, thread safety is ensured by the
`synchronized` keyword on the `Metadata#awaitUpdate` method;
In the `ProducerMetadata#awaitUpdate` method, in addition to the `synchronized`
on the `ProducerMetadata#awaitUpdate` method, {color:#FF0000}*there is a second
`synchronized` in the `SystemTime#waitObject` method;*{color}
Although we all know that `synchronized` is reentrant, it is not clear whether
the implementation of `ProducerMetadata#awaitUpdate` is inconsistent in
different versions of JDK, resulting in this exception; what is certain is that
this exception has never occurred before the 2.2.2 version of KafkaProducer
h2. Suggestion:
We can keep only one `synchronized` and remove the `synchronized` on the
`ProducerMetadata#awaitUpdate` method
--
This message was sent by Atlassian Jira
(v8.20.1#820001)
