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https://issues.apache.org/jira/browse/HIVE-12175?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15025953#comment-15025953
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Prasanth Jayachandran commented on HIVE-12175:
----------------------------------------------
May be we should list all the custom serializers that hive uses in the
documentation and provide note to user saying if any other serializer is
required at runtime then runtime exception might be thrown on failure of object
creation.
> Upgrade Kryo version to 3.0.x
> -----------------------------
>
> Key: HIVE-12175
> URL: https://issues.apache.org/jira/browse/HIVE-12175
> Project: Hive
> Issue Type: Improvement
> Components: Serializers/Deserializers
> Affects Versions: 2.0.0
> Reporter: Prasanth Jayachandran
> Assignee: Prasanth Jayachandran
> Fix For: 2.0.0
>
> Attachments: HIVE-12175.1.patch, HIVE-12175.2.patch,
> HIVE-12175.3.patch, HIVE-12175.3.patch, HIVE-12175.4.patch,
> HIVE-12175.5.patch, HIVE-12175.6.patch
>
>
> Current version of kryo (2.22) has some issue (refer exception below and in
> HIVE-12174) with serializing ArrayLists generated using Arrays.asList(). We
> need to either replace all occurrences of Arrays.asList() or change the
> current StdInstantiatorStrategy. This issue is fixed in later versions and
> kryo community recommends using DefaultInstantiatorStrategy with fallback to
> StdInstantiatorStrategy. More discussion about this issue is here
> https://github.com/EsotericSoftware/kryo/issues/216. Alternatively, custom
> serilization/deserilization class can be provided for Arrays.asList.
> Also, kryo 3.0 introduced unsafe based serialization which claims to have
> much better performance for certain types of serialization.
> Exception:
> {code}
> Caused by: java.lang.NullPointerException
> at java.util.Arrays$ArrayList.size(Arrays.java:2847)
> at java.util.AbstractList.add(AbstractList.java:108)
> at
> org.apache.hive.com.esotericsoftware.kryo.serializers.CollectionSerializer.read(CollectionSerializer.java:112)
> at
> org.apache.hive.com.esotericsoftware.kryo.serializers.CollectionSerializer.read(CollectionSerializer.java:18)
> at
> org.apache.hive.com.esotericsoftware.kryo.Kryo.readObject(Kryo.java:694)
> at
> org.apache.hive.com.esotericsoftware.kryo.serializers.ObjectField.read(ObjectField.java:106)
> ... 57 more
> {code}
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