Question about the Log Compaction

[阮良]

Hi all 


I am confused about the Log Compaction logic，use OffsetMap to deduplicating the 
log.   in my opinion when there is a hash conflict , data may be lost
Eg： Record1(key1,offset1)  Record2(key2,offset2)
Conditionhash(key1) == hash(key2)   &&  (offset1 < offset2)  
Result  Record1 will be remove by mistake 


Did I misunderstand the implementation logic?please give me some guidance, 
thank you very much


1：OffsetMap  put logic does not deal with the hash collision, if hash(key1) == 
hash(key2)key1 will be overwrire








2：the logic of retain record 

Question for KafkaRequestHandler

[阮良]

Hi Folks, 
   I am confused about the code below ，why the IO thread set the daemon ?   
in my thought , daemon thread is not suitable for some importment work 


def createHandler(id: Int): Unit = synchronized {
runnables += new KafkaRequestHandler(id, brokerId, aggregateIdleMeter, 
threadPoolSize, requestChannel, apis, time)
  KafkaThread.daemon("kafka-request-handler-" + id, runnables(id)).start()
}

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[阮良]

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