[jira] [Created] (KAFKA-8448) Too many kafka.log.Log instances (Memory Leak)

["Juan Olivares (JIRA)" <ji...@apache.org>]

Juan Olivares created KAFKA-8448:
------------------------------------

             Summary: Too many kafka.log.Log instances (Memory Leak)
                 Key: KAFKA-8448
                 URL: https://issues.apache.org/jira/browse/KAFKA-8448
             Project: Kafka
          Issue Type: Bug
    Affects Versions: 2.2.0
         Environment: Red Hat 4.4.7-16, java version "1.8.0_152", kafka_2.12-2.2.0
            Reporter: Juan Olivares


We have a custom Kafka health check which creates a topic add some ACLs (read/write topic and group), produce & consume a single message and then quickly remove it and all the related ACLs created.

We have observed that # of instances of {{kafka.log.Log}} keep growing, while there's no evidence of topics being leaked, neither running {{/opt/kafka/bin/kafka-topics.sh --zookeeper localhost:2181 --describe}} , nor looking at the disk directory where topics are stored.

After looking at the heapdump we've observed the following
 - None of the {{kafka.log.Log}} references ({{currentLogs}}, {{logsToBeDeleted }} and {{logsToBeDeleted}}) in {{kafka.log.LogManager}} is holding the big amount of {{kafka.log.Log}} instances.
 - The only reference preventing {{kafka.log.Log}} to be Garbage collected seems to be {{java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue}} which contains schedule tasks created with the name {{PeriodicProducerExpirationCheck}}.

I can see in the code that for every {{kafka.log.Log}} a task with this name is scheduled.
{code:java}
  scheduler.schedule(name = "PeriodicProducerExpirationCheck", fun = () => {
    lock synchronized {
      producerStateManager.removeExpiredProducers(time.milliseconds)
    }
  }, period = producerIdExpirationCheckIntervalMs, delay = producerIdExpirationCheckIntervalMs, unit = TimeUnit.MILLISECONDS)
{code}

However it seems those tasks are never unscheduled/cancelled



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)