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https://issues.apache.org/jira/browse/KAFKA-2235?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14971848#comment-14971848
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Ivan Simoneko commented on KAFKA-2235:
--------------------------------------
The core problem is that offset map is limited by number of messages while
segment is limited by size in bytes and this patch doesn't fix it. But the way
it handles the problem (just throws exception end stops compacting) is
consistent with other errors in compactor.
> LogCleaner offset map overflow
> ------------------------------
>
> Key: KAFKA-2235
> URL: https://issues.apache.org/jira/browse/KAFKA-2235
> Project: Kafka
> Issue Type: Bug
> Components: core, log
> Affects Versions: 0.8.1, 0.8.2.0
> Reporter: Ivan Simoneko
> Assignee: Ivan Simoneko
> Fix For: 0.9.0.0
>
> Attachments: KAFKA-2235_v1.patch, KAFKA-2235_v2.patch
>
>
> We've seen log cleaning generating an error for a topic with lots of small
> messages. It seems that cleanup map overflow is possible if a log segment
> contains more unique keys than empty slots in offsetMap. Check for baseOffset
> and map utilization before processing segment seems to be not enough because
> it doesn't take into account segment size (number of unique messages in the
> segment).
> I suggest to estimate upper bound of keys in a segment as a number of
> messages in the segment and compare it with the number of available slots in
> the map (keeping in mind desired load factor). It should work in cases where
> an empty map is capable to hold all the keys for a single segment. If even a
> single segment no able to fit into an empty map cleanup process will still
> fail. Probably there should be a limit on the log segment entries count?
> Here is the stack trace for this error:
> 2015-05-19 16:52:48,758 ERROR [kafka-log-cleaner-thread-0]
> kafka.log.LogCleaner - [kafka-log-cleaner-thread-0], Error due to
> java.lang.IllegalArgumentException: requirement failed: Attempt to add a new
> entry to a full offset map.
> at scala.Predef$.require(Predef.scala:233)
> at kafka.log.SkimpyOffsetMap.put(OffsetMap.scala:79)
> at
> kafka.log.Cleaner$$anonfun$kafka$log$Cleaner$$buildOffsetMapForSegment$1.apply(LogCleaner.scala:543)
> at
> kafka.log.Cleaner$$anonfun$kafka$log$Cleaner$$buildOffsetMapForSegment$1.apply(LogCleaner.scala:538)
> at scala.collection.Iterator$class.foreach(Iterator.scala:727)
> at kafka.utils.IteratorTemplate.foreach(IteratorTemplate.scala:32)
> at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)
> at kafka.message.MessageSet.foreach(MessageSet.scala:67)
> at
> kafka.log.Cleaner.kafka$log$Cleaner$$buildOffsetMapForSegment(LogCleaner.scala:538)
> at
> kafka.log.Cleaner$$anonfun$buildOffsetMap$3.apply(LogCleaner.scala:515)
> at
> kafka.log.Cleaner$$anonfun$buildOffsetMap$3.apply(LogCleaner.scala:512)
> at scala.collection.immutable.Stream.foreach(Stream.scala:547)
> at kafka.log.Cleaner.buildOffsetMap(LogCleaner.scala:512)
> at kafka.log.Cleaner.clean(LogCleaner.scala:307)
> at
> kafka.log.LogCleaner$CleanerThread.cleanOrSleep(LogCleaner.scala:221)
> at kafka.log.LogCleaner$CleanerThread.doWork(LogCleaner.scala:199)
> at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:60)
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