[jira] [Created] (KAFKA-2236) offset request reply racing with segment rolling

["Alfred Landrum (JIRA)" <ji...@apache.org>]

Alfred Landrum created KAFKA-2236:
-------------------------------------

             Summary: offset request reply racing with segment rolling
                 Key: KAFKA-2236
                 URL: https://issues.apache.org/jira/browse/KAFKA-2236
             Project: Kafka
          Issue Type: Bug
          Components: core
    Affects Versions: 0.8.2.0
         Environment: Linux x86_64, java.1.7.0_72, discovered using librdkafka based client.
            Reporter: Alfred Landrum
            Priority: Critical


My use case with kafka involves an aggressive retention policy that rolls segment files frequently. My librdkafka based client sees occasional errors to offset requests, showing up in the broker log like:

[2015-06-02 02:33:38,047] INFO Rolled new log segment for 'receiver-93b40462-3850-47c1-bcda-8a3e221328ca-50' in 1 ms. (kafka.log.Log)
[2015-06-02 02:33:38,049] WARN [KafkaApi-0] Error while responding to offset request (kafka.server.KafkaApis)
java.lang.ArrayIndexOutOfBoundsException: 3
        at kafka.server.KafkaApis.fetchOffsetsBefore(KafkaApis.scala:469)
        at kafka.server.KafkaApis.fetchOffsets(KafkaApis.scala:449)
        at kafka.server.KafkaApis$$anonfun$17.apply(KafkaApis.scala:411)
        at kafka.server.KafkaApis$$anonfun$17.apply(KafkaApis.scala:402)
        at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
        at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
        at scala.collection.immutable.Map$Map1.foreach(Map.scala:109)
        at scala.collection.TraversableLike$class.map(TraversableLike.scala:244)
        at scala.collection.AbstractTraversable.map(Traversable.scala:105)
        at kafka.server.KafkaApis.handleOffsetRequest(KafkaApis.scala:402)
        at kafka.server.KafkaApis.handle(KafkaApis.scala:61)
        at kafka.server.KafkaRequestHandler.run(KafkaRequestHandler.scala:59)
        at java.lang.Thread.run(Thread.java:745)


quoting Guozhang Wang's reply to my query on the users list:

"I check the 0.8.2 code and may probably find a bug related to your issue.
Basically, segsArray.last.size is called multiple times during handling
offset requests, while segsArray.last could get concurrent appends. Hence
it is possible that in line 461, if(segsArray.last.size > 0) returns false
while later in line 468, if(segsArray.last.size > 0) could return true."


http://mail-archives.apache.org/mod_mbox/kafka-users/201506.mbox/%3CCAHwHRrUK-3wdoEAaFbsD0E859Ea0gXixfxgDzF8E3%3D_8r7K%2Bpw%40mail.gmail.com%3E




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