[KAFKA-8012] NullPointerException while truncating at high watermark can crash replica fetcher thread

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 2.2.0, 2.1.1
• Fix Version/s: 2.2.0, 2.1.2
• Component/s: core
• Assignee: Colin Hicks
• Reporter: Colin Hicks
• Created: 27/Feb/19 17:26
• Updated: 01/Mar/19 10:37
• Resolved: 01/Mar/19 00:55

Description

An NPE can occur when the replica fetcher manager simultaneously calls `removeFetcherForPartitions`, removing the corresponding partitionStates, while a replica fetcher thread attempts to truncate the same partition(s) in `truncateToHighWatermark`.

Stack trace for failure case:

java.lang.NullPointerException
at kafka.server.AbstractFetcherThread.$anonfun$truncateToHighWatermark$2(AbstractFetcherThread.scala:213)
at scala.collection.mutable.HashSet.foreach(HashSet.scala:79)
at kafka.server.AbstractFetcherThread.$anonfun$truncateToHighWatermark$1(AbstractFetcherThread.scala:211)
at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
at kafka.utils.CoreUtils$.inLock(CoreUtils.scala:251)
at kafka.server.AbstractFetcherThread.truncateToHighWatermark(AbstractFetcherThread.scala:207)
at kafka.server.AbstractFetcherThread.maybeTruncate(AbstractFetcherThread.scala:173)
at kafka.server.AbstractFetcherThread.doWork(AbstractFetcherThread.scala:112)
at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:82)

 

Issue Links

• is caused by: KAFKA-7897 Invalid use of epoch cache with old message format versions
• links to: GitHub Pull Request #6333