Thanks Priyanka.

Thanks all for sharing your help. For now I was able to fix my serialization 
issues. :)

Regards,
Raja.

From: Priyanka Gugale 
<[email protected]<mailto:[email protected]>>
Reply-To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Date: Monday, June 20, 2016 at 3:28 AM
To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Subject: Re: Kafka input operator

Hi Raja,

I have opened a pull 
request<https://github.com/apache/apex-malhar/pull/323/files> in Malhar to add 
emitTuple method to AbstractKafkaInputOperator which has KafkaMessage 
parameter. The KafkaMessage has both partitionId and offset along with the 
message. Once this gets merged, you can override only emitTuple method in your 
subclass and convert "Message" into String or bytes array. So now you won't 
have variable access problem as well as serialization issues.

-Priyanka

On Mon, Jun 20, 2016 at 3:59 AM, Thomas Weise 
<[email protected]<mailto:[email protected]>> wrote:
kafka.message.Message is the problem, MutablePair has a no-arg constructor and 
should be serializable for Kryo,


On Sun, Jun 19, 2016 at 3:10 PM, <[email protected]<mailto:[email protected]>> 
wrote:
The Pairs in Apache common are not Kryo serializable. You can use other pair 
data structure. For example KeyValuePair in Malhar library

Siyuan

Sent from my iPhone

On Jun 19, 2016, at 14:58, Raja.Aravapalli 
<[email protected]<mailto:[email protected]>> wrote:


Hi Priyanka,

I am writing to read the messages in the next operator with input port defined 
like the below,


public transient DefaultInputPort<MutablePair<Message, MutablePair<Long, 
Integer>>> input = new DefaultInputPort<MutablePair<Message, MutablePair<Long, 
Integer>>>()

Application is failing with below exception:


2016-06-19 16:54:45,498 ERROR codec.DefaultStatefulStreamCodec 
(DefaultStatefulStreamCodec.java:fromDataStatePair(98)) - Catastrophic Error: 
Execution halted due to Kryo exception!
com.esotericsoftware.kryo.KryoException: Class cannot be created (missing 
no-arg constructor): kafka.message.Message
Serialization trace:
left (org.apache.commons.lang3.tuple.MutablePair)
        at 
com.esotericsoftware.kryo.Kryo$DefaultInstantiatorStrategy.newInstantiatorOf(Kryo.java:1228)
        at com.esotericsoftware.kryo.Kryo.newInstantiator(Kryo.java:1049)
        at com.esotericsoftware.kryo.Kryo.newInstance(Kryo.java:1058)


Any help please.

Regards,
Raja.

From: "Raja.Aravapalli" 
<[email protected]<mailto:[email protected]>>
Reply-To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Date: Sunday, June 19, 2016 at 12:22 AM
To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Subject: Re: Kafka input operator


Thanks for the response Priyanka…

But, when I try to put in my own package, some of the protected variables are 
not accessible!!!!


Regards,
Raja.

From: Priyanka Gugale 
<[email protected]<mailto:[email protected]>>
Reply-To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Date: Saturday, June 18, 2016 at 10:29 AM
To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Subject: Re: Kafka input operator


Hi,

Yes sure, you can use any package name you want. In fact better you put this 
class outside Malhar jar. Just keep the Malhar jar in your class path.

-Priyanka

On Jun 17, 2016 8:03 PM, "Raja.Aravapalli" 
<[email protected]<mailto:[email protected]>> wrote:

Hi Priyanka,

Can this be done from a class outside the package 
“com.datatorrent.contrib.kafka;” ?

I don’t want to disturb the source :(



Regards,
Raja.

From: "Raja.Aravapalli" 
<[email protected]<mailto:[email protected]>>
Date: Friday, June 17, 2016 at 5:38 AM
To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Subject: Re: Kafka input operator


Hi Priyanka,

I am using kafka version 0.8.x.

Awesome. Yes. This is what is want. I shall test this and share my updates. 
Having one kafka operator like this in Malhar, will be a very good one. I don’t 
see such availability in Storm as well!!



Regards,
Raja.

From: Priyanka Gugale 
<[email protected]<mailto:[email protected]>>
Reply-To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Date: Friday, June 17, 2016 at 2:05 AM
To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Subject: Re: Kafka input operator

Hi Raja,

I have quickly wrote an operator to fulfill your requirement. The code is 
available 
here<https://github.com/apache/apex-malhar/compare/master...DT-Priyanka:Kafka-input-updates>.
 Let me know if this addresses your usecase.

-Priyanka

On Fri, Jun 17, 2016 at 11:32 AM, Priyanka Gugale 
<[email protected]<mailto:[email protected]>> wrote:
Hi Raja,

You will need to update other places as well (I guess it's replay other than 
emitTuples) . But I think it is not feasible to replicate emitTuples code in 
subclass as many of the parent class variables are private. I would try to 
figure out if there is any other way.

Can you please confirm which Kafka version you are using?

-Priyanka

On Thu, Jun 16, 2016 at 8:39 PM, Raja.Aravapalli 
<[email protected]<mailto:[email protected]>> wrote:

Hi Chaitanya,

Would the below changes you proposed enough to retrieve partition & offset ?

I see emitTuple(Message msg) is being called at various places in the code… 
please advise. Thank you.


Regards,
Raja.

From: "Raja.Aravapalli" 
<[email protected]<mailto:[email protected]>>
Date: Tuesday, June 14, 2016 at 9:50 PM
To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Subject: Re: Kafka input operator


Thanks for the response Chaitanya. I will follow the suggestions to retrieve 
Kafka partitionId & offset!!


Regards,
Raja.

From: Chaitanya Chebolu 
<[email protected]<mailto:[email protected]>>
Reply-To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Date: Monday, June 13, 2016 at 3:06 AM
To: "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Subject: Re: Kafka input operator

Hi Raja,

   I think you are using 0.8 version of kafka operator. There is no such 
operator in Malhar.  To meet your requirement, please do as below:

  Create a new class which extend from AbstractKafkaInputOperator. Override the 
API "void emitTuples()" and create the output port of type 
MutablePair<Message,MutablePair<long,int>>

Copy the emitTuples() from AbstractKafkaInputOperator and change the below line:
emitTuple(message.msg) to
outputPort.emit(new MutablePair<>(message.getMsg(),new 
MutablePair<>(message.getOffset(),message.getKafkaPart().getPartitionId())));

Regards,
Chaitanya


On Sat, Jun 11, 2016 at 7:56 PM, Raja.Aravapalli 
<[email protected]<mailto:[email protected]>> wrote:

Hi

Does anyone have an idea, if any of the existing kafka input operators give the 
ability to retrieve  kafka Partition ID & Offset a particular message came 
from, along with the messages ?


Thanks a lot in advance.


Regards,
Raja.





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