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From Roman Shtykh <rsht...@yahoo.com.INVALID>
Subject Re: kafka connect(copycat) question
Date Thu, 10 Dec 2015 11:34:54 GMT

I just thought it would be helpful to have more detailed information on converters (including
what you described here) on 


On Wednesday, November 11, 2015 6:59 AM, Ewen Cheslack-Postava <ewen@confluent.io> wrote:
Hi Venkatesh,

If you're using the default settings included in the sample configs, it'll
expect JSON data in a special format to support passing schemas along with
the data. This is turned on by default because it makes it possible to work
with a *lot* more connectors and data storage systems (many require
schemas!), though it does mean consuming regular JSON data won't work out
of the box. You can easily switch this off by changing these lines in the
worker config:


to be false instead. However, note that this will only work with connectors
that can work with "schemaless" data. This wouldn't work for, e.g., writing
Avro files in HDFS since they need schema information, but it might work
for other formats. This would allow you to consume JSON data from any topic
it already existed in.

Note that JSON is not the only format you can use. You can also substitute
other implementations of the Converter interface. Confluent has implemented
an Avro version that works well with our schema registry (
The JSON implementation made sense to add as the one included with Kafka
simply because it didn't introduce any other dependencies that weren't
already in Kafka. It's also possible to write implementations for other
formats (e.g. Thrift, Protocol Buffers, Cap'n Proto, MessagePack, and
more), but I'm not aware of anyone who has started to tackle those
converters yet.


On Tue, Nov 10, 2015 at 1:23 PM, Venkatesh Rudraraju <
venkatengineering@gmail.com> wrote:

> Hi,
> I am trying out the new kakfa connect service.
> version : kafka_2.11-
> mode    : standalone
> I have a conceptual question on the service.
> Can I just start a sink connector which reads from Kafka and writes to say
> HDFS ?
> From what I have tried, it's expecting a source-connector as well because
> the sink-connector is expecting a particular pattern of the message in
> kafka-topic.
> Thanks,
> Venkat



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