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https://issues.apache.org/jira/browse/KAFKA-1670?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14159749#comment-14159749
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Jun Rao commented on KAFKA-1670:
--------------------------------
The default value in LogConfig is just for unit test (so some smaller values
may make sense). In the full logic, we always pick the broker level value as
the default.
> Corrupt log files for segment.bytes values close to Int.MaxInt
> --------------------------------------------------------------
>
> Key: KAFKA-1670
> URL: https://issues.apache.org/jira/browse/KAFKA-1670
> Project: Kafka
> Issue Type: Bug
> Affects Versions: 0.8.1.1
> Reporter: Ryan Berdeen
> Assignee: Sriharsha Chintalapani
> Priority: Blocker
> Fix For: 0.8.2
>
> Attachments: KAFKA-1670.patch, KAFKA-1670_2014-10-04_20:17:46.patch
>
>
> The maximum value for the topic-level config {{segment.bytes}} is
> {{Int.MaxInt}} (2147483647). *Using this value causes brokers to corrupt
> their log files, leaving them unreadable.*
> We set {{segment.bytes}} to {{2122317824}} which is well below the maximum.
> One by one, the ISR of all partitions shrunk to 1. Brokers would crash when
> restarted, attempting to read from a negative offset in a log file. After
> discovering that many segment files had grown to 4GB or more, we were forced
> to shut down our *entire production Kafka cluster* for several hours while we
> split all segment files into 1GB chunks.
> Looking into the {{kafka.log}} code, the {{segment.bytes}} parameter is used
> inconsistently. It is treated as a *soft* maximum for the size of the segment
> file
> (https://github.com/apache/kafka/blob/0.8.1.1/core/src/main/scala/kafka/log/LogConfig.scala#L26)
> with logs rolled only after
> (https://github.com/apache/kafka/blob/0.8.1.1/core/src/main/scala/kafka/log/Log.scala#L246)
> they exceed this value. However, much of the code that deals with log files
> uses *ints* to store the size of the file and the position in the file.
> Overflow of these ints leads the broker to append to the segments
> indefinitely, and to fail to read these segments for consuming or recovery.
> This is trivial to reproduce:
> {code}
> $ bin/kafka-topics.sh --topic segment-bytes-test --create
> --replication-factor 2 --partitions 1 --zookeeper zkhost:2181
> $ bin/kafka-topics.sh --topic segment-bytes-test --alter --config
> segment.bytes=2147483647 --zookeeper zkhost:2181
> $ yes "Int.MaxValue is a ridiculous bound on file size in 2014" |
> bin/kafka-console-producer.sh --broker-list localhost:6667 zkhost:2181
> --topic segment-bytes-test
> {code}
> After running for a few minutes, the log file is corrupt:
> {code}
> $ ls -lh data/segment-bytes-test-0/
> total 9.7G
> -rw-r--r-- 1 root root 10M Oct 3 19:39 00000000000000000000.index
> -rw-r--r-- 1 root root 9.7G Oct 3 19:39 00000000000000000000.log
> {code}
> We recovered the data from the log files using a simple Python script:
> https://gist.github.com/also/9f823d9eb9dc0a410796
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