[KAFKA-9504] Memory leak in KafkaMetrics registered to MBean

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 2.4.0
• Component/s: clients
• Assignee: Unassigned
• Reporter: Andreas Holmén
• Created: 04/Feb/20 08:59
• Updated: 12/Mar/24 18:23
• Resolved: 12/Mar/24 18:23

Description

After close() called on a KafkaConsumer some registered MBeans are not unregistered causing leak.

 

 

import static org.apache.kafka.clients.consumer.ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG;
import java.lang.management.ManagementFactory;
import java.util.HashMap;
import java.util.Map;
import javax.management.MBeanServer;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.common.serialization.ByteArrayDeserializer;
public class Leaker {
 private static String bootstrapServers = "hostname:9092";
 
 public static void main(String[] args) throws InterruptedException {
  MBeanServer mBeanServer = ManagementFactory.getPlatformMBeanServer();
  Map<String, Object> props = new HashMap<>();
  props.put(BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
 
  int beans = mBeanServer.getMBeanCount();
  for (int i = 0; i < 100; i++) {
   KafkaConsumer<byte[], byte[]> consumer = new KafkaConsumer<>(props, new ByteArrayDeserializer(), new ByteArrayDeserializer());
   consumer.close();
  }
  int newBeans = mBeanServer.getMBeanCount();
  System.out.println("\nbeans delta: " + (newBeans - beans));
 }
}