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https://issues.apache.org/jira/browse/HIVE-21218?focusedWorklogId=397920&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-397920
]
ASF GitHub Bot logged work on HIVE-21218:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 04/Mar/20 22:28
Start Date: 04/Mar/20 22:28
Worklog Time Spent: 10m
Work Description: b-slim commented on pull request #933: HIVE-21218:
Adding support for Confluent Kafka Avro message format
URL: https://github.com/apache/hive/pull/933#discussion_r387973124
##########
File path: kafka-handler/README.md
##########
@@ -50,6 +50,9 @@ ALTER TABLE
SET TBLPROPERTIES (
"kafka.serde.class" = "org.apache.hadoop.hive.serde2.avro.AvroSerDe");
```
+
+If you use Confluent Avro serialzier/deserializer with Schema Registry you may
want to remove 5 bytes from beginning that represents magic byte + schema ID
from registry.
Review comment:
@davidov541 please help me understand this, the first 5 bytes on the record
am guessing it is a schema id that can be used to fetch schema from the
registry ?
**If that is correct then I think we should not call this confluent and let
me explain why.**
Imagine in the near/far future someone implement a full fledge Avro reader
that uses those five bytes to figure out schema from the schema registry what
shall we call this now ? Confluent V2 ? that is why I think it is confusing.
Thus in my opinion it is better to call it skip, and document how this can be
used to read data from Confluent Avro SerDe. Please let me know if this makes
sense to you.
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Issue Time Tracking
-------------------
Worklog Id: (was: 397920)
Time Spent: 9h 10m (was: 9h)
> KafkaSerDe doesn't support topics created via Confluent Avro serializer
> -----------------------------------------------------------------------
>
> Key: HIVE-21218
> URL: https://issues.apache.org/jira/browse/HIVE-21218
> Project: Hive
> Issue Type: Bug
> Components: kafka integration, Serializers/Deserializers
> Affects Versions: 3.1.1
> Reporter: Milan Baran
> Assignee: David McGinnis
> Priority: Major
> Labels: pull-request-available
> Attachments: HIVE-21218.2.patch, HIVE-21218.3.patch,
> HIVE-21218.4.patch, HIVE-21218.5.patch, HIVE-21218.patch
>
> Time Spent: 9h 10m
> Remaining Estimate: 0h
>
> According to [Google
> groups|https://groups.google.com/forum/#!topic/confluent-platform/JYhlXN0u9_A]
> the Confluent avro serialzier uses propertiary format for kafka value -
> <magic_byte 0x00><4 bytes of schema ID><regular avro bytes for object that
> conforms to schema>.
> This format does not cause any problem for Confluent kafka deserializer which
> respect the format however for hive kafka handler its bit a problem to
> correctly deserialize kafka value, because Hive uses custom deserializer from
> bytes to objects and ignores kafka consumer ser/deser classes provided via
> table property.
> It would be nice to support Confluent format with magic byte.
> Also it would be great to support Schema registry as well.
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