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https://issues.apache.org/jira/browse/KAFKA-1194?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16580774#comment-16580774
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Harald Kirsch commented on KAFKA-1194:
--------------------------------------
As far as I understand the issue, it might have to do with this JDK bug:
[https://bugs.openjdk.java.net/browse/JDK-4724038] which says that once a file
is mapped into memory, there is not really a way to unmap it. One has to hope
for the finalize() method to run eventually. On Windows, the effect is that
files are kept locked and cannot be deleted. The bug was opened in 2002 :), so
without someone really knowledgeable digging into this, the situation will
hardly improve :(
The Lucene folks seem to be able to deal with this somehow, or they can just
wait long enough for their mmapped index files to get unmapped. More background
for anyone interested might be found via:
https://issues.apache.org/jira/browse/LUCENE-6989
> The kafka broker cannot delete the old log files after the configured time
> --------------------------------------------------------------------------
>
> Key: KAFKA-1194
> URL: https://issues.apache.org/jira/browse/KAFKA-1194
> Project: Kafka
> Issue Type: Bug
> Components: log
> Affects Versions: 0.10.0.0, 0.11.0.0, 1.0.0
> Environment: window
> Reporter: Tao Qin
> Priority: Critical
> Labels: features, patch, windows
> Attachments: KAFKA-1194.patch, Untitled.jpg, kafka-1194-v1.patch,
> kafka-1194-v2.patch, screenshot-1.png
>
> Original Estimate: 72h
> Remaining Estimate: 72h
>
> We tested it in windows environment, and set the log.retention.hours to 24
> hours.
> # The minimum age of a log file to be eligible for deletion
> log.retention.hours=24
> After several days, the kafka broker still cannot delete the old log file.
> And we get the following exceptions:
> [2013-12-19 01:57:38,528] ERROR Uncaught exception in scheduled task
> 'kafka-log-retention' (kafka.utils.KafkaScheduler)
> kafka.common.KafkaStorageException: Failed to change the log file suffix from
> to .deleted for log segment 1516723
> at kafka.log.LogSegment.changeFileSuffixes(LogSegment.scala:249)
> at kafka.log.Log.kafka$log$Log$$asyncDeleteSegment(Log.scala:638)
> at kafka.log.Log.kafka$log$Log$$deleteSegment(Log.scala:629)
> at kafka.log.Log$$anonfun$deleteOldSegments$1.apply(Log.scala:418)
> at kafka.log.Log$$anonfun$deleteOldSegments$1.apply(Log.scala:418)
> at
> scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:59)
> at scala.collection.immutable.List.foreach(List.scala:76)
> at kafka.log.Log.deleteOldSegments(Log.scala:418)
> at
> kafka.log.LogManager.kafka$log$LogManager$$cleanupExpiredSegments(LogManager.scala:284)
> at
> kafka.log.LogManager$$anonfun$cleanupLogs$3.apply(LogManager.scala:316)
> at
> kafka.log.LogManager$$anonfun$cleanupLogs$3.apply(LogManager.scala:314)
> at
> scala.collection.TraversableLike$WithFilter$$anonfun$foreach$1.apply(TraversableLike.scala:743)
> at scala.collection.Iterator$class.foreach(Iterator.scala:772)
> at
> scala.collection.JavaConversions$JIteratorWrapper.foreach(JavaConversions.scala:573)
> at scala.collection.IterableLike$class.foreach(IterableLike.scala:73)
> at
> scala.collection.JavaConversions$JListWrapper.foreach(JavaConversions.scala:615)
> at
> scala.collection.TraversableLike$WithFilter.foreach(TraversableLike.scala:742)
> at kafka.log.LogManager.cleanupLogs(LogManager.scala:314)
> at
> kafka.log.LogManager$$anonfun$startup$1.apply$mcV$sp(LogManager.scala:143)
> at kafka.utils.KafkaScheduler$$anon$1.run(KafkaScheduler.scala:100)
> at
> java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
> at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:304)
> at
> java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:178)
> at
> java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
> at java.lang.Thread.run(Thread.java:724)
> I think this error happens because kafka tries to rename the log file when it
> is still opened. So we should close the file first before rename.
> The index file uses a special data structure, the MappedByteBuffer. Javadoc
> describes it as:
> A mapped byte buffer and the file mapping that it represents remain valid
> until the buffer itself is garbage-collected.
> Fortunately, I find a forceUnmap function in kafka code, and perhaps it can
> be used to free the MappedByteBuffer.
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